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Talarico Neto T, Magraner JM, Hahns Júnior HC, Ferreira L, Martinelli Júnior CE, Tourinho Filho H. Biphasic Kinetics of IGF-I and IGFBP-3 in Response to Military Field Training in Brazilian Air Force Recruits. Mil Med 2024:usae097. [PMID: 38687564 DOI: 10.1093/milmed/usae097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/10/2023] [Accepted: 03/14/2024] [Indexed: 05/02/2024] Open
Abstract
INTRODUCTION Insulin-like growth factor type I (IGF-I) has gained considerable notoriety in military training, primarily because it is responsible for energy deficits and sensitive to an inadequate protein intake, which are situations that are commonly experienced in specific military operations. Therefore, this study aimed to assess the kinetics of IGF-I and insulin-like growth factor binding protein type 3 (IGFBP-3) in a 4-day military field training exercise. MATERIALS AND METHODS The sample comprised 12 male soldiers (21.71 ± 1.64 years). Changes were assessed at 3 times: time 1-basal (control week); time 2-after specific military field training; and time 3-1 week after the specific training (control week). Changes in body composition and serum levels of IGF-I and IGFBP-3 were observed. RESULTS The main finding of this study was it verified the biphasic kinetics of both IGF-I and IGFBP-3 at the 3 times observed, that is, a significant drop from time 1 (basal-IGF-I: 189 ng/mL and IGFBP-3: 4.71 mg/L) to time 2 (immediately after military training-IGF-I: 162 ng/mL and IGFBP-3: 4.08 mg/L) and a subsequent recovery of these markers, with a significant increase from time 2 (immediately after military training) to time 3 (a week after military training-IGF-I: 199 ng/mL and IGFBP-3: 4.96 mg/L). CONCLUSIONS It can be concluded that IGF-I and IGFBP-3 levels respond quickly to the stimuli caused by military training, especially after specific field training. However, the same markers quickly return to their basal values after this type of training finishes, simply by following the daily routine of the battalion in the control weeks, with no specific intervention being necessary.
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Affiliation(s)
- Thomaz Talarico Neto
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | - José Maurício Magraner
- Brazilian Air Force Academy-AFA, Pirassununga, SP 13643-000, Brazil
- School of Physical Education-FEF/UNICAMP, State University of Campinas; Cidade Universitária Zeferino Vaz-Barão Geraldo, Campinas, SP 13083-970, Brazil
| | - Higino Carlos Hahns Júnior
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | | | - Carlos Eduardo Martinelli Júnior
- Faculty of Medicine of Ribeirão Preto, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | - Hugo Tourinho Filho
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
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Vikmoen O, Teien HK, Tansø R, Aandstad A, Lander E, Cumming KT, Ellefsen S, Helkala K, Raastad T. Effects of a 10-d Military Field Exercise on Body Composition, Physical Performance, and Muscle Cells in Men and Women. Med Sci Sports Exerc 2024; 56:682-696. [PMID: 37962228 DOI: 10.1249/mss.0000000000003340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
PURPOSE This study aimed to investigate the effects of a demanding military field exercise on physical performance, body composition, and muscle cellular outcomes in men and women. METHODS Ten men (20.5 ± 0.5 yr) and 8 women (21.4 ± 1.4 yr) completed a 10-d field exercise consisting of extensive physical activity with food and sleep restriction. Acquisition of body composition, physical performance, blood, and muscle biopsies samples were done before and 1, 7, and 14 d after the exercise. RESULTS There were no sex differences in the response to the exercise. Body mass was decreased with 5.6% ± 1.8% and fat mass with 31% ± 11% during the exercise. Both were still reduced after 14 d (2.5% ± 2.3%, P < 0.001, and 12.5% ± 7.7%, P < 0.001, respectively). Isometric leg strength did not change. Peak leg extension torque at 240°·s -1 and counter movement jump height were reduced with 4.6% ± 4.8% ( P = 0.012) and 6.7% ± 6.2% ( P < 0.001), respectively, and was still reduced after 14 d (4.3% ± 4.2%, P = 0.002, and 4.1% ± 4.7%, P = 0.030). No changes occurred in fiber CSA, fiber types, proteins involved in calcium handling, or HSP70. During the exercise, αB-crystallin levels decreased by 14% ± 19% ( P = 0.024) in the cytosolic fraction and staining intensity on muscle sections tended to increase (17% ± 25%, P = 0.076). MuRF1 levels in the cytosolic fraction tended to decrease (19% ± 35%) and increased with 85% ± 105% ( P = 0.003) in the cytoskeletal fraction 1 wk after the exercise. CONCLUSIONS The field exercise resulted in reduced body mass and physical performance in both sexes. The ability to produce force at high contraction velocities and explosive strength was more affected than isometric strength, but this was not related to any changes in fiber type composition, fiber area, Ca 2+ handling, or fiber type-specific muscle damage.
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Affiliation(s)
| | - Hilde Kristin Teien
- Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY
| | - Rita Tansø
- Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY
| | - Anders Aandstad
- Norwegian Defence University College, Norwegian Defence Command and Staff College, Section for Military Leadership and Sport, Oslo, NORWAY
| | - Elise Lander
- Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY
| | | | - Stian Ellefsen
- Inland Norway University of Applied Sciences, Faculty for Health and Social Sciences, Lillehammer, NORWAY
| | - Kirsi Helkala
- The Norwegian Defense University College, Norwegian Defence Cyber Academy, Lillehammer, NORWAY
| | - Truls Raastad
- Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY
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Borgenström J, Kyröläinen H, Pihlainen K, Vaara JP, Ojanen T. Effects of male paratroopers' initial body composition on changes in physical performance and recovery during a 20-day winter military field training. Appl Physiol Nutr Metab 2024; 49:437-446. [PMID: 38084583 DOI: 10.1139/apnm-2023-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Changes in physiological markers and physical performance in relation to paratroopers' initial body composition were investigated during a 20-day winter military field training (MFT) and the subsequent 10-day recovery period. Body composition, serum hormone concentrations and enzymatic biomarkers, and physical performance of 58 soldiers were measured before, during, and after MFT. Comparisons were done according to soldiers' body fat percentage before MFT between low-fat (<12% body fat) and high-fat (>12% body fat) groups. Correlations between body fat percentage preceding MFT and changes in muscle mass, physical performance, and serum hormone concentrations and enzymatic biomarkers were investigated. It was hypothesized that soldiers with a higher fat percentage would have smaller decrements in muscle mass, physical performance, and serum testosterone concentration. The change in muscle and fat mass was different between groups (p < 0.001) as the low-fat group lost 0.8 kg of muscle mass and 2.0 kg of fat mass, while there was no change in muscle mass and a loss of 3.7 kg of fat mass in the high-fat group during MFT. Fat percentage before MFT correlated with the changes in muscle mass (R2 = 0.26, p < 0.001), serum testosterone concentration (R2 = 0.22, p < 0.001), and evacuation test time (R2 = 0.10, p < 0.05) during MFT. The change in muscle mass was correlated with the changes in evacuation test time (R2 = 0.11, p < 0.05) and countermovement jump test results (R2 = 0.13, p < 0.01) during MFT. Soldiers with a higher initial fat percentage lost less muscle mass, and had smaller decrements in some aspects of physical performance, as well as in serum testosterone concentration during MFT.
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Affiliation(s)
- Jere Borgenström
- Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
| | - Heikki Kyröläinen
- Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
- Department of Leadership and Military Pedagogy, National Defence University, P.O. Box 7, 00861 Helsinki, Finland
| | - Kai Pihlainen
- Defence Command, Finnish Defence Forces, P.O. Box 919, 00131 Helsinki, Finland
| | - Jani P Vaara
- Department of Leadership and Military Pedagogy, National Defence University, P.O. Box 7, 00861 Helsinki, Finland
| | - Tommi Ojanen
- Finnish Defence Research Agency, Finnish Defence Forces, P.O. Box 5, 04401 Järvenpää, Finland
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O'Leary TJ, Gifford RM, Knight RL, Wright J, Handford S, Venables MC, Reynolds RM, Woods D, Wardle SL, Greeves JP. Sex differences in energy balance, body composition, and metabolic and endocrine markers during prolonged arduous military training. J Appl Physiol (1985) 2024; 136:938-948. [PMID: 38385180 DOI: 10.1152/japplphysiol.00864.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 02/23/2024] Open
Abstract
This study investigated sex differences in energy balance, body composition, and metabolic and endocrine markers during prolonged military training. Twenty-three trainees (14 women) completed 44-wk military training (three terms of 14 wk with 2-wk adventurous training). Dietary intake and total energy expenditure were measured over 10 days during each term by weighed food and doubly labeled water. Body composition was measured by dual-energy X-ray absorptiometry (DXA) at baseline and at the end of each term. Circulating metabolic and endocrine markers were measured at baseline and at the end of terms 2 and 3. Absolute energy intake and total energy expenditure were higher, and energy balance was lower, for men than women (P ≤ 0.008). Absolute energy intake and balance were lower, and total energy expenditure was higher, during term 2 than terms 1 and 3 (P < 0.001). Lean mass did not change with training (P = 0.081). Fat mass and body fat increased from term 1 to terms 2 and 3 (P ≤ 0.045). Leptin increased from baseline to terms 2 and 3 in women (P ≤ 0.002) but not in men (P ≥ 0.251). Testosterone and free androgen index increased from baseline to term 3 (P ≤ 0.018). Free thyroxine (T4) decreased and thyroid-stimulating hormone (TSH) increased from baseline to term 2 and term 3 (P ≤ 0.031). Cortisol decreased from baseline to term 3 (P = 0.030). IGF-I and total triiodothyronine (T3) did not change with training (P ≥ 0.148). Men experienced greater energy deficits than women during military training due to higher total energy expenditure.NEW & NOTEWORTHY Energy deficits are common in military training and can result in endocrine and metabolic disturbances. This study provides first investigation of sex differences in energy balance, body composition, and endocrine and metabolic markers in response to prolonged and arduous military training. Men experienced greater energy deficits than women due to higher energy expenditure, which was not compensated for by increased energy intake. These energy deficits were not associated with decreases in fat or lean mass or metabolic or endocrine function.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
- Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Robert M Gifford
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Rebecca L Knight
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
| | - Jennifer Wright
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
| | - Sally Handford
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
| | - Michelle C Venables
- Medical Research Council, Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Rebecca M Reynolds
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - David Woods
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, United Kingdom
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
- Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
- Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
- Division of Surgery and Interventional Science, UCL, London, United Kingdom
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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Ross JA, Heebner NR. No pain, no gain: The military overtraining hypothesis of musculoskeletal stress and injury. Physiother Theory Pract 2023; 39:2289-2299. [PMID: 35695302 DOI: 10.1080/09593985.2022.2082346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 04/16/2022] [Accepted: 05/21/2022] [Indexed: 10/18/2022]
Abstract
The purpose of this manuscript is to present a model of military overtraining and subsequent injury, discharge, and disability. Military training and combat operations are physically and physiologically demanding, placing great strain on the musculoskeletal system of warfighters. Non-battle musculoskeletal injuries (MSKI) are common and present a serious threat to operational readiness in today's military. MSKI risk stratification and prevention are an active area of research and is steeped in the background of sports science. Here, a model is proposed that incorporates the theory of General Adaptation Syndrome to describe how military training stressors may exceed that of training in traditional athletics and may induce sub-optimal training stressors. Positive feedback loops are discussed to explain how military overtraining (MOT) creates a system of ever-increasing stressors that can only be fully understood in the greater context of all environmental factors leading to overtraining. The Military Overtraining Hypothesis (MOTH) is proposed as a model that encapsulates the elevated MSKI risk in combat arms and other operational military personnel as an effort to broaden understanding of multifactorial military MSKI etiologies and as a tool for researchers and commanders to contextualize MSKI research and risk mitigation interventions.
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Affiliation(s)
- Jeremy A Ross
- Sports Medicine Research Institute, University of Kentucky, Lexington USA
| | - Nicholas R Heebner
- Sports Medicine Research Institute, University of Kentucky, Lexington USA
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Stellingwerff T, Mountjoy M, McCluskey WT, Ackerman KE, Verhagen E, Heikura IA. Review of the scientific rationale, development and validation of the International Olympic Committee Relative Energy Deficiency in Sport Clinical Assessment Tool: V.2 (IOC REDs CAT2)-by a subgroup of the IOC consensus on REDs. Br J Sports Med 2023; 57:1109-1118. [PMID: 37752002 DOI: 10.1136/bjsports-2023-106914] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2023] [Indexed: 09/28/2023]
Abstract
Relative Energy Deficiency in Sport (REDs) has various different risk factors, numerous signs and symptoms and is heavily influenced by one's environment. Accordingly, there is no singular validated diagnostic test. This 2023 International Olympic Committee's REDs Clinical Assessment Tool-V.2 (IOC REDs CAT2) implements a three-step process of: (1) initial screening; (2) severity/risk stratification based on any identified REDs signs/symptoms (primary and secondary indicators) and (3) a physician-led final diagnosis and treatment plan developed with the athlete, coach and their entire health and performance team. The CAT2 also introduces a more clinically nuanced four-level traffic-light (green, yellow, orange and red) severity/risk stratification with associated sport participation guidelines. Various REDs primary and secondary indicators have been identified and 'weighted' in terms of scientific support, clinical severity/risk and methodological validity and usability, allowing for objective scoring of athletes based on the presence or absence of each indicator. Early draft versions of the CAT2 were developed with associated athlete-testing, feedback and refinement, followed by REDs expert validation via voting statements (ie, online questionnaire to assess agreement on each indicator). Physician and practitioner validity and usability assessments were also implemented. The aim of the IOC REDs CAT2 is to assist qualified clinical professionals in the early and accurate diagnosis of REDs, with an appropriate clinical severity and risk assessment, in order to protect athlete health and prevent prolonged and irreversible outcomes of REDs.
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Affiliation(s)
- Trent Stellingwerff
- Canadian Sport Institute Pacific, Victoria, British Columbia, Canada
- Exercise Science, Physical & Health Education, University of Victoria, Victoria, British Columbia, Canada
| | - Margo Mountjoy
- Association for Summer Olympic International Federations (ASOIF), Lausanne, Switzerland
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | | | - Kathryn E Ackerman
- Wu Tsai Female Athlete Program, Division of Sports Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Evert Verhagen
- Amsterdam Collaboration on Health and Safety in Sports and Department of Public and Occupational Health, VU University Medical Centre Amsterdam, Amsterdam, The Netherlands
| | - Ida A Heikura
- Canadian Sport Institute Pacific, Victoria, British Columbia, Canada
- Exercise Science, Physical & Health Education, University of Victoria, Victoria, British Columbia, Canada
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Martins C, S N, Sr C, Jf R, Hunter GR, Gower BA. Association between fat-free mass loss, changes in appetite and weight regain in individuals with obesity. J Nutr 2023; 153:1330-1337. [PMID: 36963504 DOI: 10.1016/j.tjnut.2023.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 03/26/2023] Open
Abstract
BACKGROUND The role of fat-free mass loss (FFML) in modulating weight regain, in individuals with obesity, as well as the potential mechanisms involved, remain inconsistent. AIMS To determine if % FFML following weight loss (WL) is a predictor of weight regain, and to investigate the association between %FFML and changes in appetite markers. METHODS Seventy individuals with obesity (BMI: 36±4kg/m2; age: 44±9 years; 29 males) underwent 8 weeks of a very low-energy diet (550-660 kcal/day), followed by 4 weeks of gradual refeeding and weight stabilization, and a 9-month maintenance program (eucaloric diet). Body weight and body composition (fat mass (FM) and FFM) (primary outcomes), as well as ß-hydroxybutyrate (ßHB) plasma concentration (a marker of ketosis) in fasting and appetite-related hormones (ghrelin, glucagon-like peptide 1, peptide YY, and cholecystokinin) and subjective appetite feelings, in fasting and every 30 minutes after a fixed breakfast for 2.5h (secondary outcomes), were measured at baseline, week 9 and 1 year (and week 13 in 35 subjects (25 males)). The association between FFML, weight regain and changes in appetite was assessed by linear regression. RESULTS WL at week 9 was 17.5±4.3kg and %FFML 20.4±10.6%. Weight regain at 1 year was 1.7±8.2kg (8.8±45.0%). After adjusting for WL and FM at baseline, %FFML at week 9 was not a significant predictor of weight regain. Similar results were seen at week 13. The greater the %FFML at week 9, but not 13, the smaller the reduction, or greater the increase in basal ghrelin concentration (ß:-3.2; 95% CI: -5.0, -1.1; P=0.003), even after adjusting for WL and ß-hydroxybutyrate. CONCLUSION %FFML was not a significant predictor of weight regain at 1-year in individuals with obesity. However, a greater %FFML was accompanied by a greater increase in ghrelin secretion under ketogenic conditions, suggesting a link between FFM and appetite regulation. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov identifier NCT01834859.
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Affiliation(s)
- Catia Martins
- Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), USA; Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Centre for Obesity and Innovation (ObeCe), Clinic of Surgery, St. Olav University Hospital, Trondheim, Norway.
| | - Nymo S
- Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Nord-Trøndelag Hospital Trust, Clinic of Surgery, Namsos Hospital, Norway
| | - Coutinho Sr
- Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Public Health Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo (UiO), Norway
| | - Rehfeld Jf
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Gary R Hunter
- Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), USA
| | - B A Gower
- Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), USA
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Prevalence of low energy availability and associations with seasonal changes in salivary hormones and IgA in elite male Gaelic footballers. Eur J Nutr 2023; 62:1809-1820. [PMID: 36841899 PMCID: PMC9968222 DOI: 10.1007/s00394-023-03112-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 02/07/2023] [Indexed: 02/27/2023]
Abstract
PURPOSE Evidence suggests low energy availability (LEA) is prevalent in elite male Gaelic football (GF) players. Previous research in male and female team sports found LEA may negatively impact endocrine function. The aim of this study was to examine the seasonal variations in energy availability (EA) and its associations with salivary measures in elite male GF players across the competitive season. METHODS Energy availability was assessed using field-based methods in conjunction with salivary testosterone (s-T), cortisol (s-C) and immunoglobin A (s-IgA) concentrations at pre-season (PRE), in-season (IN) and post-season (POST). RESULTS 38% reported LEA at PRE, 33% at IN, and 28.5% at POST. s-C, s-T and s-IgA levels were within normal ranges at PRE, IN and POST. Salivary cortisol declined significantly from PRE to IN, remaining reduced at POST. Salivary testosterone decreased significantly from PRE to IN but was significantly elevated at POST compared to IN. Salivary IgA was significantly greater at POST than IN. No significant associations were found between s-C or s-T and EA at any time point. Pre-season s-IgA exhibited a significant inverse association with PRE EA. Decreased s-IgA flow rate and s-IgA secretion rate were significantly associated with decreased EA at PRE. Reduced carbohydrate (CHO) intake was also associated with decreased s-IgA secretion rate at PRE. CONCLUSION This study suggests that LEA is prevalent in elite male GF players, but is not associated with s-C or s-T. However, EA is associated with s-IgA which may impact the immune system. Therefore, education and interventions surrounding the prevalence and associations of EA should be implemented in this population.
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The Effects of Intermittent Diet Breaks during 25% Energy Restriction on Body Composition and Resting Metabolic Rate in Resistance-Trained Females: A Randomized Controlled Trial. J Hum Kinet 2023; 86:117-132. [PMID: 37181269 PMCID: PMC10170537 DOI: 10.5114/jhk/159960] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The purpose of this study was to examine the effects of intermittent versus continuous energy restriction on body composition, resting metabolic rate, and eating behaviors in resistance-trained females. Thirty-eight resistance-trained females (mean ± standard deviation age: 22.3±4.2 years) were randomized to receive either six weeks of a continuous 25% reduction in energy intake (n= 18), or one week of energy balance after every two weeks of 25% energy restriction (eight weeks total; n= 20). Participants were instructed to ingest 1.8 g protein/kilogram bodyweight per day and completed three weekly supervised resistance training sessions throughout the intervention. There were no differences between groups for changes over time in body composition, resting metabolic rate, or seven of the eight measured eating behavior variables (p > 0.05). However, a significant group-by-time interaction for disinhibition (p < 0.01) from the Three-Factor Eating Questionnaire was observed, with values (± standard error) in the continuous group increasing from 4.91 ± 0.73 to 6.17 ± 0.71, while values in the intermittent group decreased from 6.80 ± 0.68 to 6.05 ± 0.68. Thus, diet breaks do not appear to induce improvements in body composition or metabolic rate in comparison with continuous energy restriction over six weeks of dieting, but may be employed for those who desire a short-term break from an energy-restricted diet without fear of fat regain. While diet breaks may reduce the impact of prolonged energy restriction on measures of disinhibition, they also require a longer time period that may be less appealing for some individuals.
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Berryman CE, McClung HL, Sepowitz JJ, Gaffney‐Stomberg E, Ferrando AA, McClung JP, Pasiakos SM. Testosterone status following short-term, severe energy deficit is associated with fat-free mass loss in U.S. Marines. Physiol Rep 2022; 10:e15461. [PMID: 36117330 PMCID: PMC9483439 DOI: 10.14814/phy2.15461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023] Open
Abstract
The objective of this study was to determine metabolic and physiological differences between males with low testosterone (LT) versus those with normal testosterone (NT) following a period of severe energy deficit. In this secondary analysis, 68 male US Marines (mean ± SD, 24.6 ± 2.4 y) were dichotomized by testosterone concentration (< or ≥ 10.5 nmol/L as determined from a single blood sample collected between 0600-0630 after an 8-10 h overnight fast by automated immunoassay) following 7 days of near complete starvation (~300 kcal consumed/d, ~85% energy deficit) during Survival, Evasion, Resistance, and Escape (SERE) training. Dietary intake was assessed before (PRE) SERE. Body composition (dual-energy x-ray absorptiometry and peripheral quantitative computed tomography) and whole-body protein turnover (15 N alanine) were assessed before (PRE) and after (POST) SERE. Mean testosterone concentrations decreased PRE (17.5 ± 4.7 nmol/L) to POST (9.8 ± 4.0 nmol/L, p < 0.0001). When volunteers were dichotomized by POST testosterone concentrations [NT (n = 24) 14.1 ± 3.4 vs. LT (n = 44): 7.5 ± 1.8 nmol/L, p < 0.0001], PRE BMI, total fat mass, trunk fat mass, and testosterone were greater and the diet quality score and total carbohydrate intake were lower in NT compared to LT (p ≤ 0.05). LT lost more fat-free mass and less fat mass, particularly in the trunk region, compared to NT following SERE (p-interaction≤0.044). Whole-body protein synthesis, net balance, and flux decreased and whole-body protein breakdown increased from PRE to POST in both groups (p-time ≤0.025). Following short-term, severe energy deficit, Marines who exhibited low testosterone had greater fat-free mass loss than those who maintained normal testosterone concentrations. Altering body composition and dietary strategies prior to physical training that elicits severe energy deficit may provide an opportunity to attenuate post-training decrements in testosterone and its associated effects (e.g., loss of lean mass, performance declines, fatigue).
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Affiliation(s)
- Claire E. Berryman
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
- Department of Nutrition and Integrative PhysiologyFlorida State UniversityTallahasseeFloridaUSA
| | - Holly L. McClung
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - John J. Sepowitz
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Erin Gaffney‐Stomberg
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Arny A. Ferrando
- Department of Geriatrics, The Center for Translational Research in Aging & LongevityDonald W. Reynolds Institute of Aging, University of Arkansas for Medical SciencesLittle RockArkansasUSA
| | - James P. McClung
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stefan M. Pasiakos
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Beyl RA, Church DD, Ferrando AA, Pasiakos SM, Rood JC. Testosterone Undecanoate Administration Prevents Declines in Fat-Free Mass but not Physical Performance During Simulated Multi-Stressor Military Operations. J Appl Physiol (1985) 2022; 133:426-442. [PMID: 35796614 PMCID: PMC9359646 DOI: 10.1152/japplphysiol.00190.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CONTEXT Male military personnel conducting strenuous operations experience reduced testosterone, muscle mass, and performance. Pharmacological restoration of normal testosterone may attenuate performance decrements by mitigating muscle loss. Previously, administering testosterone enanthate (200 mg/week) during energy deficit prompted supraphysiological testosterone concentrations and lean mass gain without preventing isokinetic/isometric deterioration. Whether administering a practical dose of testosterone protects muscle and performance during strenuous operations is undetermined. OBJECTIVE Test the effects of a single dose of testosterone on body composition and military-relevant physical performance during a simulated operation. METHODS After a 7-day baseline phase (P1), 32 males (mean±SD; 77.1±12.3 kg, 26.5±4.4 years) received a single dose of either testosterone undecanoate (750 mg; TEST) or placebo (PLA) before a 20-day simulated military operation (P2), followed by a 23-day recovery (P3). Assessments included body composition and physical performance at the end of each phase and circulating endocrine biomarkers throughout the study. RESULTS Total and free testosterone concentrations in TEST were greater than PLA throughout most of P2 (p<0.05), but returned to P1 values during P3. Fat-free mass (FFM) was maintained from P1 to P2 in TEST (mean±SE; 0.41±0.65 kg, p=0.53), but decreased in PLA (-1.85±0.69 kg, p=0.01) and recovered in P3. Regardless of treatment, total body mass and fat mass decreased from P1 to P2 (p<0.05), but did not fully recover by P3. Physical performance decreased during P2 (p<0.05) and recovered by P3, regardless of treatment. CONCLUSIONS Administering testosterone undecanoate before a simulated military operation protected FFM but did not prevent decrements in physical performance.
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Robbie A Beyl
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
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12
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Influence of fat-free mass and resting metabolic rate on increased food reinforcement after exercise training. SPORT SCIENCES FOR HEALTH 2022. [DOI: 10.1007/s11332-021-00876-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Abstract
Purpose
Models of appetite control have been largely based on negative feedback from gut and adipose signaling to central appetite centers. However, contemporary models posit that fat-free mass (FFM) or the energy demand of FFM [i.e., resting metabolic rate (RMR)] may play a primary role in the motivational drive for food intake (i.e., food reinforcement). The relative reinforcing value of food (RRVfood) is associated with energy intake (EI) and increases with an acute energy deficit. Chronic exercise-induced energy deficits lead to alterations in fat mass (FM), FFM, and RMR and provide an opportunity to test whether change in (∆) FM, ∆FFM, ∆usual EI, or ∆RMR are associated with ∆RRVfood.
Methods
Participants (n = 29, BMI = 25–35 kg/m2) engaged in aerobic exercise expending 300 or 600 kcal, 5 days/weeks for 12 weeks. The reinforcing value of food (PMaxfood) was measured via a computer-based operant responding task and RRVfood was calculated as the reinforcing value of food relative to non-eating sedentary behaviors. RMR was determined by indirect calorimetry and body composition by DXA.
Results
Post-training FFM correlated with usual post-training EI (rs = 0.41, p < 0.05), PMaxfood (rs=0.52, p < 0.01), and RMR (rs = 0.85, p < 0.0001). ∆RMR negatively correlated with ∆PMaxfood (rs = − 0.38, p < 0.05) and with ∆RRVfood (rs = − 0.37, p < 0.05). ∆PMaxfood and ∆RRVfood were not associated with ∆FFM (p = 0.71, p = 0.57, respectively).
Conclusions
Reductions in RMR with weight loss may increase food reinforcement as means of restoring FFM and RMR to pre-weight loss amounts. Limiting reductions in RMR during weight loss may benefit weight maintenance by restricting increases in food reinforcement after weight loss.
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13
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Smith SJ, Teo SYM, Lopresti AL, Heritage B, Fairchild TJ. Examining the effects of calorie restriction on testosterone concentrations in men: a systematic review and meta-analysis. Nutr Rev 2021; 80:1222-1236. [PMID: 34613412 DOI: 10.1093/nutrit/nuab072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
CONTEXT Testosterone concentrations decline with age, and lower testosterone concentrations are associated with several morbidities, including sexual dysfunction, obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome. OBJECTIVE Because dietary habits play a critical role in weight regulation and T2DM management, the aim of this systematic review and meta-analysis was to summarize and critically evaluate the evidence from randomized controlled trials to determine the effects of calorie restriction (CR) on testosterone concentrations in men. DATA SOURCES A literature search was conducted across 4 databases, from their inception until March 2020. DATA EXTRACTION The screening and data extraction were completed by 2 authors independently, and in a blinded manner, according to a priori inclusion and exclusion criteria. DATA ANALYSIS Of the 4198 studies identified from the initial search, 7 randomized controlled trials were included for data extraction. Significant increases in total testosterone concentrations were reported in 3 of 4 studies in which CR was examined with overweight or obese men, compared with the control groups. Significant decreases in total testosterone concentrations were reported in 2 of 3 studies in which the effects of CR were examined with normal-weight, healthy men, compared with the control groups. In all 4 studies that examined the effect of CR on sex hormone-binding globulin concentrations, the intervention significantly increased sex hormone-binding globulin concentrations compared with that of the control groups irrespective of body composition. CONCLUSION This systematic review and meta-analysis provide some evidence that CR affects testosterone concentrations in men and this effect depends on their body mass index. PROSPERO registration no. CRD42020173102.
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Affiliation(s)
- Stephen J Smith
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Shaun Y M Teo
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Adrian L Lopresti
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Brody Heritage
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Timothy J Fairchild
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
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14
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Gan LSH, Fan PWP, Zhang J, Nolte HW, Friedl KE, Nindl BC, Lee JKW. Changes in energy balance, body composition, metabolic profile and physical performance in a 62-day Army Ranger training in a hot-humid environment. J Sci Med Sport 2021; 25:89-94. [PMID: 34507882 DOI: 10.1016/j.jsams.2021.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/01/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES To determine the physiological effects of multiple stressors including energy deficit during a 62-day Ranger course in a hot-humid environment. DESIGN Prospective cohort design. METHODS Food intake data were collected daily and energy expenditure at each of the three phases of the course was estimated by the doubly-labeled water method. Anthropometry, hydration status, stress and metabolic hormones, handgrip strength and lower explosive power were measured at the start and at the end of each phase. RESULTS Seventeen male participants (age: 24.5 ± 3.2 years, height: 173.9 ± 5.1 cm, body mass: 69.3 ± 3.2 kg, BMI: 22.9 ± 0.9 kg/m2, percent body fat: 14 ± 5%) completed the study. Mean total daily energy expenditure was 4756 kcal/day and mean daily energy intake was 3882 kcal/day. An 18% energy deficit resulted in an average body mass loss of 4.6 kg, comprising mostly fat mass. Participants with higher baseline adiposity (>15% body fat) lost more fat mass and gained (rather than lost) muscle mass compared to those with lower baseline adiposity. Handgrip strength declined only at the end of Phase I, while lower body explosive power declined progressively throughout the course. Lean mass in arms and legs was correlated with initial grip strength and lower body explosive power, but only at the start of the course. CONCLUSIONS Physiologically demanding Ranger training in an equatorial environment is at least as metabolically demanding and stressful as other similar high-risk training courses, as demonstrated by the stress and metabolic endocrine responses, changes in body composition, and reduction in explosive power. Moreover, the smaller body size of Asian soldiers may confer an energetic advantage over larger sized Western counterparts.
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Affiliation(s)
- Linda S H Gan
- Combat Protection and Performance Programme, Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore
| | - Priscilla W P Fan
- Combat Protection and Performance Programme, Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore
| | - Junren Zhang
- Army Medical Services, Singapore Armed Forces, Singapore
| | - Heinrich W Nolte
- Movement Physiology Research Laboratory, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - Karl E Friedl
- U.S. Army Research Institute of Environmental Medicine, United States
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, United States
| | - Jason K W Lee
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Global Asia Institute, National University of Singapore, Singapore; N.1 Institute for Health, National University of Singapore, Singapore; Institute for Digital Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore.
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15
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Church DD, Ferrando AA, Rood JC, Pasiakos SM. Effects of testosterone undecanoate on performance during multi-stressor military operations: A trial protocol for the Optimizing Performance for Soldiers II study. Contemp Clin Trials Commun 2021; 23:100819. [PMID: 34278044 PMCID: PMC8264529 DOI: 10.1016/j.conctc.2021.100819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022] Open
Abstract
Background Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations. Methods In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood. Conclusions OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS. Trial Registration ClinicalTrials.gov Identifier: NCT04120363.
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Key Words
- Anabolism
- And hypogonadism
- BIA, bioelectrical impedance analysis
- D2O, deuterium
- DSMB, data and safety monitoring board
- DXA, dual-energy x-ray absorptiometry
- ECW, extracellular water
- EDef, energy deficit
- EIEE, exercise-induced energy expenditure
- Energy deficit
- Exercise
- FBR, fractional breakdown rate
- FFM, fat-free mass
- FSR, fractional synthetic rate
- HR, heart rate
- HRR, heart rate reserve
- ICW, intracellular water
- ID, identification
- IRB, Institutional Review Board
- MRE, Meal
- Optimizing Performance for Soldiers Trial I, OPS II
- Optimizing Performance for Soldiers Trial II, PAR-Q+
- Pennington Biomedical Research Center, PLA
- Physical Activity Readiness Questionnaire+, PB
- Ready-to-Eat, OPS I
- Skeletal muscle
- Sleep deprivation
- TBW, total body water
- TDEE, total daily energy expenditure
- TDEI, total daily energy intake
- TEST, testosterone experimental group
- VO2max, maximal cardiorespiratory fitness
- VO2peak, peak oxygen uptake
- WBGT, wet bulb globe temperature
- placebo experimental group, PS
- protein breakdown, PBRC
- protein synthesis, Q
- ratings of perceived exertion, SUSOPS
- repetition maximum, RNA
- respiratory exchange ratio, RM
- ribonucleic acid, RPE
- sustained, multi-stressor military operations
- whole-body nitrogen flux, RER
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
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Conkright WR, Beckner ME, Sinnott AM, Eagle SR, Martin BJ, Lagoy AD, Proessl F, Lovalekar M, Doyle TLA, Agostinelli P, Sekel NM, Flanagan SD, Germain A, Connaboy C, Nindl BC. Neuromuscular Performance and Hormonal Responses to Military Operational Stress in Men and Women. J Strength Cond Res 2021; 35:1296-1305. [PMID: 33780395 DOI: 10.1519/jsc.0000000000004013] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Conkright, WR, Beckner, ME, Sinnott, AM, Eagle, SR, Martin, BJ, Lagoy, AD, Proessl, F, Lovalekar, M, Doyle, TLA, Agostinelli, P, Sekel, NM, Flanagan, SD, Germain, A, Connaboy, C, and Nindl, BC. Neuromuscular performance and hormonal responses to military operational stress in men and women. J Strength Cond Res 35(5): 1296–1305, 2021—Women have recently been integrated into ground close combat positions; however, there are limited data in women in these roles. We aimed to test the hypothesis that there would be no sex-specific neuromuscular responses, but hormonal signaling would be differentially impacted when exposed to simulated military operational stress (SMOS). Neuromuscular performance was assessed daily using a tactical mobility test (TMT) in 54 male and 15 female military members. Blood was drawn before/after TMT. Mood states were assessed each morning. Unloaded 300-m shuttle time increased 6% in both sexes and remained 7% higher after 1 day of recovery compared with baseline (p < 0.05 for both), whereas performance was maintained in other TMT events (p > 0.05). Growth hormone increased in men, but not women, before to after TMT (p < 0.001 vs. p = 0.086). Women experienced a greater decline in insulin-like growth factor-I across days compared with men (
= 0.778 vs. 0.209, respectively, p < 0.001). Brain-derived neurotrophic factor increased significantly in men only from before to after TMT on day 1 (men: +107% vs. women: +10%) but no difference on days 3 or 4. Cortisol increased 69% from before to after TMT when averaged by sex and day. Negative mood states (depression, tension, and anger) and altered hormonal concentrations were associated with poorer TMT performance. Acute SMOS differentially impacted circulating hormonal milieu in men and women, but no differences in physical performance responses. Unloaded 300-m shuttle was negatively impacted while other fitness domains were maintained. Relationships between performance and mood/endocrine signaling highlight the potential for self-report measures and biomarkers to serve as indicators of performance change.
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Affiliation(s)
- William R Conkright
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Meaghan E Beckner
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Aaron M Sinnott
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn R Eagle
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian J Martin
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alice D Lagoy
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Felix Proessl
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tim L A Doyle
- Faculty of Medicine, Health, and Human Sciences, Macquarie University, Sydney, Australia
| | - Phil Agostinelli
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nicole M Sekel
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne Germain
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Christopher Connaboy
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bradley C Nindl
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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Royer SD, Poploski KM, Ross JA, Heebner NR, Abt JP, Sheppard RL, Winters JD. Training Strategies Maintain Performance Characteristics in Marines Selected for Marine Forces Special Operations Individualized Training Course. Mil Med 2021; 187:e1271-e1277. [PMID: 33825899 DOI: 10.1093/milmed/usab124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/15/2021] [Accepted: 03/23/2021] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Marines must complete an intensive Assessment and Selection (A&S) course before becoming a U.S. Marine Forces Special Operations Command (MARSOC) Raider. Following selection, marines are given training recommendations designed to maintain performance characteristics deemed relevant to successfully complete a rigorous 9-month Individualized Training Course (ITC). However, training strategies are individually implemented by the marine, and the time between the two courses is highly irregular, ranging between 2 months and 24 months based on operational factors related to military occupational specialty (MOS). The purpose of this study was to evaluate changes in performance between the completion of A&S and the start of ITC and to examine if the duration between courses and previous MOS influenced changes in performance. MATERIALS AND METHODS Body fat percentage (BF%), anaerobic power (AP), anaerobic capacity (AC), aerobic capacity (VO2max), knee flexion (KF), knee extension (KE), trunk extension (TE), and trunk flexion (TF) isokinetic strength were collected on 38 marines (age: 25.1 ± 2.7 years, height: 1.77 ± 0.05 m, mass: 83.2 ± 7.7 kg, Post-A&S to ITC start: 204.1 ± 68.4 days) following A&S and directly before ITC. RESULTS Pre-ITC students had significantly greater mass (P = .002), BF% (P = .000), and AP (P = .039). There were no significant changes in AC (P = .170), VO2max (P = .259), KF (P = .400), KE (P = .320), TE (P = .178), and TF (P = .643). There was no significant relationship between performance outcomes and time between courses and previous MOS. CONCLUSION Current training strategies appear effective at addressing performance deficits that occur as a result of A&S, while maintaining high levels of KF, KE, TE, TF, AC, and VO2max. However, pre-ITC students still exhibited AP deficits compared to active marine raiders, so forthcoming programming may benefit from an increased emphasis on AP. Assessment of additional selectees at these timepoints, as well as students before A&S may provide valuable information to MARSOC human performance specialists to develop programing, ultimately leading to a higher ITC graduation rate, increased force readiness, and decreased financial burden forcewide.
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Affiliation(s)
- Scott D Royer
- Sports Medicine Research Institute, College of Health Sciences, University of Kentucky, Lexington, KY 40506, USA
| | - Kathleen M Poploski
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jeremy A Ross
- Sports Medicine Research Institute, College of Health Sciences, University of Kentucky, Lexington, KY 40506, USA
| | - Nicholas R Heebner
- Sports Medicine Research Institute, College of Health Sciences, University of Kentucky, Lexington, KY 40506, USA
| | - John P Abt
- Children's Health Andrews Institute for Orthopedics & Sports Medicine, Plano, TX 75024, USA
| | - Ryan L Sheppard
- United States Marine Forces Special Operations Command, Camp Lejeune, NC 28547, USA
| | - Joshua D Winters
- Sports Medicine Research Institute, College of Health Sciences, University of Kentucky, Lexington, KY 40506, USA
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18
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Miles-Chan JL, Isacco L. Weight cycling practices in sport: A risk factor for later obesity? Obes Rev 2021; 22 Suppl 2:e13188. [PMID: 33372395 DOI: 10.1111/obr.13188] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022]
Abstract
Weight cycling, repeated cycles of weight loss and weight regain over time, is commonplace amongst many population groups. Although the effect of weight cycling on future obesity and cardiometabolic risk is still hotly debated, evidence does indicate that individuals who were normal weight prior to weight cycling are more susceptible to its adverse consequences than those who were overweight or with obesity. Athletes, and particularly those who compete in the so-called weight-sensitive sports, are prone to dieting and weight cycling practice owing to the competitive advantage to be gained from manipulating their body weight. However, in comparison with the general population, athletes tend to be leaner and weight loss phases more rapid and superimposed on a background of a high level of physical activity. In this context, it can be questioned whether weight cycling in this subpopulation will indeed increase risk for future obesity. It is perhaps surprising that despite recognition that athletes commonly partake in weight cycling during their career, studies are scarce and firm conclusions regarding the effect of this practice on future cardiometabolic risk remain to be drawn. In this review, we examine weight cycling prevalence and strategies in athletes and the current evidence relating to its short- and long-term consequences. In addition, a conceptual framework relating the dynamics of weight loss and recovery to athlete characteristics will be discussed, highlighting the need for well-controlled, prospective studies in this specific subpopulation.
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Affiliation(s)
- Jennifer L Miles-Chan
- Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Laurie Isacco
- AME2P Laboratory (AME2P, EA 3533), CRNH Auvergne, Clermont Auvergne University, Clermont-Ferrand, France.,Research Unit EA3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance Health Innovation Platform, University of Bourgogne Franche-Comté, Besançon, France
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19
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Dulloo AG. Physiology of weight regain: Lessons from the classic Minnesota Starvation Experiment on human body composition regulation. Obes Rev 2021; 22 Suppl 2:e13189. [PMID: 33543573 DOI: 10.1111/obr.13189] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022]
Abstract
Since its publication in 1950, the Biology of Human Starvation, which describes the classic longitudinal Minnesota Experiment of semistarvation and refeeding in healthy young men, has been the undisputed source of scientific reference about the impact of long-term food deprivation on human physiology and behavior. It has been a guide in developing famine and refugee relief programs for international agencies, in exploring the effects of food deprivation on the cognitive and social functioning of those with anorexia nervosa and bulimia nervosa, and in gaining insights into metabolic adaptations that undermine obesity therapy and cachexia rehabilitation. In more recent decades, the application of a systems approach to the analysis of its data on longitudinal changes in body composition, basal metabolic rate, and food intake during the 24 weeks of semistarvation and 20 weeks of refeeding has provided rare insights into the multitude of control systems that govern the regulation of body composition during weight regain. These have underscored an internal (autoregulatory) control of lean-fat partitioning (highly sensitive to initial adiposity), which operates during weight loss and weight regain and revealed the existence of feedback loops between changes in body composition and the control of food intake and adaptive thermogenesis for the purpose of accelerating the recovery of fat mass and fat-free mass. This paper highlights the general features and design of this grueling experiment of simulated famine that has allowed the unmasking of fundamental control systems in human body composition autoregulation. The integration of its outcomes constitutes the "famine reactions" that drive the normal physiology of weight regain and obesity relapse and provides a mechanistic "autoregulation-based" explanation of how dieting and weight cycling, transition to sedentarity, or developmental programming may predispose to obesity. It also provides a system physiology framework for research toward elucidating proteinstatic and adipostatic mechanisms that control hunger-appetite and adaptive thermogenesis, with major implications for a better understanding (and management) of cachexia, obesity, and cardiometabolic diseases.
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Affiliation(s)
- Abdul G Dulloo
- Faculty of Science and Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, Fribourg, Switzerland
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20
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O'Leary TJ, Walsh NP, Casey A, Izard RM, Tang JCY, Fraser WD, Greeves JP. Supplementary Energy Increases Bone Formation during Arduous Military Training. Med Sci Sports Exerc 2021; 53:394-403. [PMID: 32701874 DOI: 10.1249/mss.0000000000002473] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE This study aimed to investigate the effect of supplementary energy on bone formation and resorption during arduous military training in energy deficit. METHODS Thirty male soldiers completed an 8-wk military combat course (mean ± SD, age = 25 ± 3 yr, height = 1.78 ± 0.05 m, body mass = 80.9 ± 7.7 kg). Participants received either the habitual diet (control group, n = 15) or an additional 5.1 MJ·d-1 to eliminate the energy deficit (supplemented group, n = 15). Circulating markers of bone formation and resorption, and reproductive, thyroid, and metabolic status, were measured at baseline and weeks 6 and 8 of training. RESULTS Bone-specific alkaline phosphatase decreased in controls (-4.4 ± 1.9 μg·L-1) and increased in the supplemented group (16.0 ± 6.6 μg·L-1), between baseline and week 8 (P < 0.001). Procollagen type 1 N-terminal propeptide increased between baseline and week 6 for both groups (5.6 ± 8.1 μg·L-1, P = 0.005). Beta carboxy-terminal cross-linking telopeptide of type 1 collagen decreased between baseline and week 8 for both groups (-0.16 ± 0.20 μg·L-1, P < 0.001). Prolactin increased from baseline to week 8 for the supplemented group (148 ± 151 IU·L-1, P = 0.041). The increase in adiponectin from baseline to week 8 was higher in controls (4.3 ± 1.8 mg·L-1, P < 0.001) than that in the supplemented group (1.4 ± 1.0 mg·L-1, P < 0.001). Insulin-like growth factor binding protein-3 was lower at week 8 than baseline for controls (-461 ± 395 ng·mL-1, P < 0.001). CONCLUSION The increase in bone-specific alkaline phosphatase, a marker of bone formation, with supplementation supports a role of energy in osteoblastic activity; the implications for skeletal adaptation and stress fracture risk are unclear. The mechanism is likely through protecting markers of metabolic, but not reproductive or thyroid, function.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, UNITED KINGDOM
| | - Neil P Walsh
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UNITED KINGDOM
| | - Anna Casey
- Army Health and Performance Research, Army Headquarters, Andover, UNITED KINGDOM
| | - Rachel M Izard
- Department of Occupational Medicine, HQ Army Recruiting and Initial Training Command, Upavon, UNITED KINGDOM
| | - Jonathan C Y Tang
- Norwich Medical School, University of East Anglia, Norwich, UNITED KINGDOM
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21
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de Barros TR, Salerno VP, Ponce T, Mainenti MRM. Body Composition Modifications Due to the "Search, Rescue and Survival Training" in Male Military Firefighter Cadets. Mil Med 2021; 187:e160-e166. [PMID: 33399870 DOI: 10.1093/milmed/usaa571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/15/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION To train and prepare cadets for a career as firefighters in Rio de Janeiro, the second-year students of the Officers Training Course are submitted to a Search, Rescue, and Survival Training (SRST) course, which is characterized by long periods of high physical exertion and sleep restriction during a 9-day instruction module, and food restriction during a 7-day survival module. The present study investigated changes in the body composition of 39 male cadets submitted to SRST during training and 4 weeks of recovery with no restrictions in food consumption. MATERIALS AND METHODS Each cadet was evaluated by anthropometric measurements at six time points: pre-SRST; after the first module; after the second module; and after 1, 2, and 4 weeks of recovery. Measurements included body girths and skinfolds, to estimate trunk (chest and waist) and limbs (arm and thigh) dimensions, as well as body composition. Repeated measures ANOVA and Friedman test were applied (depending on each data distribution). RESULTS Statistically significant decreases in body weight (76.2; 69.8-87.2 to 63.9; 58.9-73.5 kg) and fat free mass (FFM, 69.2; 63.7-77.2 to 60.1; 56.2-68.0 kg) were observed following the second module of SRST. Following a single week of recovery, the FFM returned to pre-SRST values. Body weight returned to pre-training levels in 2 weeks. Body fat percentage and mass also significantly decreased during SRST (9.0; 7.7-12.3 to 6.5; 5.1-9.3% and 6.9; 5.6-10.0 to 6.9; 5.6-10.0 kg, respectively), which showed a slower and more gradual recovery that reached pre-SRST values after 4 weeks. The girths of arm, thigh, chest and waist significantly decreased due to SRST. The girths of the limbs (arm and thigh) returned to pre-training values after one month of recovery, while the girths of the trunk (chest and waist) did not return to pre-SRST values during the study period. CONCLUSIONS The findings suggest that men who experience periods of high energy demands and sleep restriction followed by a period of food restriction will endure unavoidable physical consequences that can be mostly reversed by a 1-month recovery.
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Affiliation(s)
- Thiago Ramos de Barros
- Dom Pedro II Military Firefighter Academy, Rio de Janeiro Fire Department, Rio de Janeiro, State of Rio de Janeiro 21660-001, Brazil.,Physical Education College of the Brazilian Army, Brazilian Army, Rio de Janeiro, State of Rio de Janeiro 22291-090, Brazil.,Department of Biosciences Physical Activity, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-599, Brazil
| | - Verônica Pinto Salerno
- Department of Biosciences Physical Activity, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-599, Brazil
| | - Thalita Ponce
- Dom Pedro II Military Firefighter Academy, Rio de Janeiro Fire Department, Rio de Janeiro, State of Rio de Janeiro 21660-001, Brazil.,Department of Biosciences Physical Activity, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-599, Brazil
| | - Míriam Raquel Meira Mainenti
- Physical Education College of the Brazilian Army, Brazilian Army, Rio de Janeiro, State of Rio de Janeiro 22291-090, Brazil
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22
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Bennett AN, Dyball DM, Boos CJ, Fear NT, Schofield S, Bull AMJ, Cullinan P. Study protocol for a prospective, longitudinal cohort study investigating the medical and psychosocial outcomes of UK combat casualties from the Afghanistan war: the ADVANCE Study. BMJ Open 2020; 10:e037850. [PMID: 33127630 PMCID: PMC7604820 DOI: 10.1136/bmjopen-2020-037850] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/16/2020] [Accepted: 09/21/2020] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION The Afghanistan war (2003-2014) was a unique period in military medicine. Many service personnel survived injuries of a severity that would have been fatal at any other time in history; the long-term health outcomes of such injuries are unknown. The ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) study aims to determine the long-term effects on both medical and psychosocial health of servicemen surviving this severe combat related trauma. METHODS AND ANALYSIS ADVANCE is a prospective cohort study. 1200 Afghanistan-deployed male UK military personnel and veterans will be recruited and will be studied at 0, 3, 6, 10, 15 and 20 years. Half are personnel who sustained combat trauma; a comparison group of the same size has been frequency matched based on deployment to Afghanistan, age, sex, service, rank and role. Participants undergo a series of physical health tests and questionnaires through which information is collected on cardiovascular disease (CVD), CVD risk factors, musculoskeletal disease, mental health, functional and social outcomes, quality of life, employment and mortality. ETHICS AND DISSEMINATION The ADVANCE Study has approval from the Ministry of Defence Research Ethics Committee (protocol no:357/PPE/12) agreed 15 January 2013. Its results will be disseminated through manuscripts in clinical/academic journals and presentations at professional conferences, and through participant and stakeholder communications. TRIAL REGISTRATION NUMBER The ADVANCE Study is registered at ISRCTN ID: ISRCTN57285353.
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Affiliation(s)
- Alexander N Bennett
- Academic Department of Military Rehabilitation, Defence Medical Rehabilitation Centre, Stanford Hall, Loughborough, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Daniel Mark Dyball
- Academic Department of Military Rehabilitation, Defence Medical Rehabilitation Centre, Stanford Hall, Loughborough, UK
- King's Centre for Military Health Research, King's College London, London, UK
| | - Christopher J Boos
- Department of Cardiology, University Hospital Dorset, NHS Trust, Poole, UK
| | - Nicola T Fear
- King's Centre for Military Health Research, King's College London, London, UK
- Academic Department for Military Mental Health, King's College London, London, UK
| | - Susie Schofield
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Anthony M J Bull
- Centre for Blast Injury Studies, Imperial College London, London, UK
| | - Paul Cullinan
- Occupational and Environmental Medicine, National Heart and Lung Institute, Imperial College, London, UK
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23
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Hinde KL, O'Leary TJ, Greeves JP, Wardle SL. Measuring Protein Turnover in the Field: Implications for Military Research. Adv Nutr 2020; 12:887-896. [PMID: 33079983 PMCID: PMC8166569 DOI: 10.1093/advances/nmaa123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 11/15/2022] Open
Abstract
Protein turnover reflects the continual synthesis and breakdown of body proteins, and can be measured at a whole-body (i.e. aggregated across all body proteins) or tissue (e.g. skeletal muscle only) level using stable isotope methods. Evaluating protein turnover in free-living environments, such as military training, can help inform protein requirements. We undertook a narrative review of published literature with the aim of reviewing the suitability of, and advancements in, stable isotope methods for measuring protein turnover in field research. The 2 primary approaches for measuring protein turnover are based on precursor- and end-product methods. The precursor method is the gold-standard for measuring acute (over several hours) skeletal muscle protein turnover, whereas the end-product method measures chronic (over several weeks) skeletal muscle protein turnover and provides the opportunity to monitor free-living activities. Both methods require invasive procedures such as the infusion of amino acid tracers and muscle biopsies to assess the uptake of the tracer into tissue. However, the end-product method can also be used to measure acute (over 9-24 h) whole-body protein turnover noninvasively by ingesting 15N-glycine, or equivalent isotope tracers, and collecting urine samples. The end-product method using 15N-glycine is a practical method for measuring whole-body protein turnover in the field over short (24 h) time frames and has been used effectively in recent military field research. Application of this method may improve our understanding of protein kinetics during conditions of high physiological stress in free-living environments such as military training.
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Affiliation(s)
- Katrina L Hinde
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom,Division of Surgery & Interventional Science, University College London, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom,Division of Surgery & Interventional Science, University College London, London, United Kingdom,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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24
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Ross JA, Thomas DT, Winters JD, Royer SD, Halagarda CJ, Sheppard R, Abt J, Heebner NR. Military Protein Intake Related to Strength and Fat Mass Independent of Energy Intake. Mil Med 2020; 185:e1671-e1678. [PMID: 32633753 DOI: 10.1093/milmed/usaa151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION Kinetic military units operate in austere training environments and deprivation not commonly experienced by competitive athletes. Nutritional strategies to protect against decrements in performance and potential injury risk may differ for these two groups. A cross sectional analysis was conducted to determine energy and macronutrient characteristics associated with performance metrics. MATERIALS AND METHODS 78 male subjects (age: 28.4 ± 6.0 years, height: 178.3 ± 6.7 cm, mass: 84.3 ± 9.4 kg, 8.5 ± 5.8 years of service) assigned to Marine Corps Forces Special Operations Command completed a 1-day performance assessment. Body mass, lean body mass, fat mass (FM), aerobic capacity (VO2max), lactate inflection point (LT), anaerobic power, anaerobic capacity, knee flexion strength, knee extension strength, peak knee flexion strength, and peak knee extension strength outcome values were recorded. Dietary intake was collected using automated self-administered 24-hour dietary recall (ASA24). Performance assessment scores were compared with macronutrient intake and controlled for energy intake using analysis of covariance. RESULTS Differences in knee flexion strength, knee extension strength, peak knee flexion strength, and peak knee extension strength were significant across low (LPRO), medium (MPRO), and high (HPRO) protein intake groups (p < 0.05) with LPRO performance metrics significantly lower than both MPRO and HPRO and MPRO significantly lower than HPRO. FM was significantly higher in LPRO than MPRO or HPRO (p < 0.05). Low carbohydrate intake (LCHO) was associated with greater body mass and FM compared with high (HCHO) (p < 0.05). There was no association between fat intake and any variable. CONCLUSIONS Increases in protein intake may have beneficial performance effects independent of total energy intake, while moderate increases in carbohydrate intake may not be sufficient to enhance physical performance in a special operations population.
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Affiliation(s)
- Jeremy A Ross
- Sports Medicine Research Institute, University of Kentucky, 720 Sports Center Dr. Lexington, KY 40506
| | - D Travis Thomas
- Sports Medicine Research Institute, University of Kentucky, 720 Sports Center Dr. Lexington, KY 40506
| | - Joshua D Winters
- Sports Medicine Research Institute, University of Kentucky, 720 Sports Center Dr. Lexington, KY 40506
| | - Scott D Royer
- Sports Medicine Research Institute, University of Kentucky, 720 Sports Center Dr. Lexington, KY 40506
| | | | - Ryan Sheppard
- United States Marine Forces Special Operations Command, SC Box 20116 Camp Lejeune, NC 28542
| | - John Abt
- Children's Health Andrews Institute for Orthopaedics and Sports Medicine, 7211 Preston Rd. Suite T1200, Plano, TX 75024
| | - Nicholas R Heebner
- Sports Medicine Research Institute, University of Kentucky, 720 Sports Center Dr. Lexington, KY 40506
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25
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O'Leary TJ, Wardle SL, Greeves JP. Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military. Front Nutr 2020; 7:142. [PMID: 32984399 PMCID: PMC7477333 DOI: 10.3389/fnut.2020.00142] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/15/2022] Open
Abstract
Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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26
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Pasiakos SM. Nutritional Requirements for Sustaining Health and Performance During Exposure to Extreme Environments. Annu Rev Nutr 2020; 40:221-245. [PMID: 32530730 DOI: 10.1146/annurev-nutr-011720-122637] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary guidelines are formulated to meet minimum nutrient requirements, which prevent deficiencies and maintain health, growth, development, and function. These guidelines can be inadequate and contribute to disrupted homeostasis, lean body mass loss, and deteriorated performance in individuals who are working long, arduous hours with limited access to food in environmentally challenging locations. Environmental extremes can elicit physiological adjustments that alone alter nutrition requirements by upregulating energy expenditure, altering substrate metabolism, and accelerating body water and muscle protein loss. The mechanisms by which the environment, including high-altitude, heat, and cold exposure, alters nutrition requirements have been studied extensively. This contemporary review discusses physiological adjustments to environmental extremes, particularly when those adjustments alter dietary requirements.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760, USA;
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27
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Vikmoen O, Teien HK, Raustøl M, Aandstad A, Tansø R, Gulliksrud K, Skare M, Raastad T. Sex differences in the physiological response to a demanding military field exercise. Scand J Med Sci Sports 2020; 30:1348-1359. [DOI: 10.1111/sms.13689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 03/26/2020] [Accepted: 04/09/2020] [Indexed: 11/26/2022]
Affiliation(s)
- Olav Vikmoen
- Comprehensive Defence Division Norwegian Defence Research Establishment Kjeller Norway
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Hilde Kristin Teien
- Comprehensive Defence Division Norwegian Defence Research Establishment Kjeller Norway
| | - Marius Raustøl
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Anders Aandstad
- Norwegian Defence Command and Staff College Section for Military Leadership and Sport Norwegian Defence University College Oslo Norway
| | - Rita Tansø
- Comprehensive Defence Division Norwegian Defence Research Establishment Kjeller Norway
| | - Kristine Gulliksrud
- Comprehensive Defence Division Norwegian Defence Research Establishment Kjeller Norway
| | - Magnhild Skare
- Faculty of Education Norwegian Defence University College Oslo Norway
| | - Truls Raastad
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
- Norwegian Defence Command and Staff College Section for Military Leadership and Sport Norwegian Defence University College Oslo Norway
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28
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Differential recovery rates of fitness following U.S. Army Ranger training. J Sci Med Sport 2020; 23:529-534. [DOI: 10.1016/j.jsams.2019.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 11/22/2022]
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29
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Øfsteng SJ, Garthe I, Jøsok Ø, Knox S, Helkala K, Knox B, Ellefsen S, Rønnestad BR. No effect of increasing protein intake during military exercise with severe energy deficit on body composition and performance. Scand J Med Sci Sports 2020; 30:865-877. [DOI: 10.1111/sms.13634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/21/2022]
Affiliation(s)
| | - Ina Garthe
- Norwegian Olympic Sport Center Oslo Norway
| | - Øyvind Jøsok
- Inland Norway University of Applied Sciences Lillehammer Norway
- Norwegian Defence Cyber Academy Lillehammer Norway
| | - Silje Knox
- Norwegian Defence Cyber Academy Lillehammer Norway
| | | | - Ben Knox
- Norwegian Defence Cyber Academy Lillehammer Norway
| | - Stian Ellefsen
- Inland Norway University of Applied Sciences Lillehammer Norway
- Innlandet Hospital Trust Brumunddal Norway
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30
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Karl JP, Berryman CE, Harris MN, Lieberman HR, Gadde KM, Rood JC, Pasiakos SM. Effects of Testosterone Supplementation on Ghrelin and Appetite During and After Severe Energy Deficit in Healthy Men. J Endocr Soc 2020; 4:bvaa024. [PMID: 32258956 DOI: 10.1210/jendso/bvaa024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/26/2020] [Indexed: 12/17/2022] Open
Abstract
Background Severe energy deficits cause interrelated reductions in testosterone and fat free mass. Testosterone supplementation may mitigate those decrements, but could also reduce circulating concentrations of the orexigenic hormone ghrelin, thereby exacerbating energy deficit by suppressing appetite. Objective To determine whether testosterone supplementation during severe energy deficit influences fasting and postprandial ghrelin concentrations and appetite. Design and methods Secondary analysis of a randomized, double-blind trial that determined the effects of testosterone supplementation on body composition changes during and following severe energy deficit in nonobese, eugonadal men. Phase 1 (PRE-ED): 14-day run-in; phase 2: 28 days, 55% energy deficit with 200 mg testosterone enanthate weekly (TEST; n = 24) or placebo (PLA; n = 26); phase 3: free-living until body mass recovered (end-of-study; EOS). Fasting and postprandial acyl ghrelin and des-acyl ghrelin concentrations and appetite were secondary outcomes measured during the final week of each phase. Results Fasting acyl ghrelin concentrations, and postprandial acyl and des-acyl ghrelin concentrations increased in PLA during energy deficit then returned to PRE-ED values by EOS, but did not change in TEST (phase-by-group, P < 0.05). Correlations between changes in free testosterone and changes in fasting acyl ghrelin concentrations during energy deficit (ρ = -0.42, P = 0.003) and body mass recovery (ρ = -0.38; P = 0.01) were not mediated by changes in body mass or body composition. Transient increases in appetite during energy deficit were not affected by testosterone treatment. Conclusions Testosterone supplementation during short-term, severe energy deficit in healthy men prevents deficit-induced increases in circulating ghrelin without blunting concomitant increases in appetite. Clinical Trials Registration www.clinicaltrials.gov NCT02734238 (registered 12 April 2016).
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Claire E Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA.,Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Melissa N Harris
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Kishore M Gadde
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Jennifer C Rood
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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31
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How dieting might make some fatter: modeling weight cycling toward obesity from a perspective of body composition autoregulation. Int J Obes (Lond) 2020; 44:1243-1253. [PMID: 32099104 PMCID: PMC7260129 DOI: 10.1038/s41366-020-0547-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/09/2020] [Accepted: 02/06/2020] [Indexed: 01/28/2023]
Abstract
The notion that dieting makes some people fatter has in the past decade gained considerable interest from both epidemiological predictions and biological plausibility. Several large-scale prospective studies have suggested that dieting to lose weight is associated with future weight gain and obesity, with such predictions being stronger and more consistent among dieters who are in the normal range of body weight rather than in those with obesity. Furthermore, the biological plausibility that dieting predisposes people who are lean (rather than those with overweight or obesity) to regain more body fat than what had been lost (referred to as fat overshooting) has recently gained support from a re-analysis of data on body composition during weight loss and subsequent weight recovery from the classic longitudinal Minnesota Starvation Experiment. These have revealed an inverse exponential relationship between the amount of fat overshot and initial adiposity, and have suggested that a temporal desynchronization in the recoveries of fat and lean tissues, in turn residing in differences in lean-fat partitioning during weight loss vs. during weight recovery (with fat recovery faster than lean tissue recovery) is a cardinal feature of fat overshooting. Within a conceptual framework that integrates the relationship between post-dieting fat overshooting with initial adiposity, the extent of weight loss and the differential lean-fat partitioning during weight loss vs. weight recovery, we describe here a mathematical model of weight cycling to predict the excess fat that could be gained through repeated dieting and multiple weight cycles from a standpoint of body composition autoregulation.
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32
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Vrijkotte S, Roelands B, Pattyn N, Meeusen R. The Overtraining Syndrome in Soldiers: Insights from the Sports Domain. Mil Med 2020; 184:e192-e200. [PMID: 30535270 DOI: 10.1093/milmed/usy274] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/22/2018] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION Soldiers are exposed to extreme training regimens in order to optimally prepare for real battle. High attrition rates are a known issue during training courses, especially for elite troops. An underlying factor might be the disbalance between stress/strain and recovery. The aim of this review is to give insight in the current knowledge about functional overreaching (FOR), non-FOR (NFOR), and the overtraining syndrome (OTS) in the military. MATERIALS AND METHODS A systematic literature review was conducted. PubMed, IngentaConnect, Science Direct, and Web of Science were screened for the following keywords and combinations of search terms; military, personnel, OT, soldier. RESULTS Seven studies investigating the effects of OT during training courses were selected. The definitions used for OT varied widely and there is no systematic use of markers to determine FOR, NFOR, or the OTS in the military. CONCLUSIONS Much research on NFOR/OTS has been conducted in the sports domain and the military could make use of these insights to promote a more efficient balance between training load and recovery. It is suggested to regularly test soldiers on physical performance, psychomotor speed and mood using ideally a military-specific test or the 1.5-mile run, psychomotor vigilance test and Profile of Mood States. The two-bout exercise test can be used as a specific test if previous testing indicates the development of NFOR/OTS and can be combined with metabolic and immunological testing to exclude pathological causes.
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Affiliation(s)
- Susan Vrijkotte
- Human Physiology Research Group, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium.,LIFE Department, Vital Signs and Performance Monitoring (VIPER), Royal Military Academy, Avenue de la Renaissancelaan 30, Brussels, Belgium.,Zorggroep Solis, Hermelijn 2, Deventer, The Netherlands
| | - Bart Roelands
- Human Physiology Research Group, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium
| | - Nathalie Pattyn
- Human Physiology Research Group, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium.,LIFE Department, Vital Signs and Performance Monitoring (VIPER), Royal Military Academy, Avenue de la Renaissancelaan 30, Brussels, Belgium.,Department of Experimental and Applied Psychology, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium
| | - Romain Meeusen
- Human Physiology Research Group, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium
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Abstract
The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and female physique athletes in the contest preparation and recovery period. As optimal protein intake is largely related to one’s skeletal muscle mass, current evidence supports a range of 1.8-2.7 g/kg. Furthermore, as a benefit from having adequate carbohydrate to fuel performance and activity, low-end fat intake during contest preparation of 10-25% of calories allows for what calories remain in the “energy budget” to come from carbohydrate to mitigate the negative impact of energy restriction and weight loss on training performance. For nutrient timing, we recommend consuming four or five protein boluses per day with one consumed near training and one prior to sleep. During competition periods, slower rates of weight loss (≤0.5% of body mass per week) are preferable for attenuating the loss of fat-free mass with the use of intermittent energy restriction strategies, such as diet breaks and refeeds, being possibly beneficial. Additionally, physiological and psychological factors are covered, and potential best-practice guidelines are provided for disordered eating and body image concerns since physique athletes present with higher incidences of these issues, which may be potentially exacerbated by certain traditional physique practices. We also review common peaking practices, and the critical transition to the post-competition period.
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Biopsychology of human appetite — understanding the excitatory and inhibitory mechanisms of homeostatic control. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hattersley J, Wilson AJ, Thake CD, Facer-Childs J, Stoten O, Imray C. Metabolic rate and substrate utilisation resilience in men undertaking polar expeditionary travel. PLoS One 2019; 14:e0221176. [PMID: 31415661 PMCID: PMC6695185 DOI: 10.1371/journal.pone.0221176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/31/2019] [Indexed: 11/24/2022] Open
Abstract
The energy expenditure and substrate utilisation were measured in 5 men pre- and post- a 67 day, 1750km unassisted Antarctic traverse from the Hercules Inlet to the Ross Sea Ice via the South pole pulling sledges weighing 120kg whilst experiencing temperatures as low as -57°C. A 36-hours protocol in a whole body calorimeter was employed to measure periods of rest, sleep and three periods of standardised stepping exercises at 80, 100 and 120 steps min-1; participants were fed isocalorically. Unlike previous expeditions where large weight loss was reported, only a modest loss of body weight (7%, P = 0.03) was found; fat tissue was reduced by 53% (P = 0.03) together with a small, but not statistically significant, increase in lean tissue weight (P = 0.18). This loss occurred despite a high-energy intake (6500 kcal/day) designed to match energy expenditure. An energy balance analysis suggested the loss in body weight could be due to the energy requirements of thermoregulation. Differences in energy expenditure [4.9 (0.1) vs 4.5 (0.1) kcal/min. P = 0.03], carbohydrate utilisation [450 (180) vs 569 (195) g/day; P = 0.03] and lipid utilisation [450 (61) vs 388 (127) g/day, P = 0.03] at low levels of exertion were different from pre-expedition values. Only carbohydrate utilisation remained statistically significant when normalised to body weight. The differences in energy expenditure and substrate utilisation between the pre- and post-expedition for other physiological states (sleeping, resting, higher levels of exercise, etc) were small and not statistically significant. Whilst inter-subject variability was large, there was a tendency for increased carbohydrate utilisation, post-expedition, when fasted that decreased upon feeding.
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Affiliation(s)
- John Hattersley
- Coventry NIHR CRF Human Metabolic Research Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
- School of Engineering, University of Warwick, Coventry, United Kingdom
- Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
- * E-mail:
| | - Adrian J. Wilson
- Coventry NIHR CRF Human Metabolic Research Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
- Department of Physics, University of Warwick, Coventry, United Kingdom
| | - C. Doug Thake
- Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | - Jamie Facer-Childs
- Institute of Child Health, University College London, London, United Kingdom
| | - Oliver Stoten
- Emergency Department, Royal Bournemouth Hospital, Bournemouth, Uinted Kingdom
| | - Chris Imray
- Coventry NIHR CRF Human Metabolic Research Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
- Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
- Department of Vascular and Renal Transplant Surgery, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
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Effects of testosterone supplementation on body composition and lower-body muscle function during severe exercise- and diet-induced energy deficit: A proof-of-concept, single centre, randomised, double-blind, controlled trial. EBioMedicine 2019; 46:411-422. [PMID: 31358477 PMCID: PMC6711889 DOI: 10.1016/j.ebiom.2019.07.059] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/23/2019] [Accepted: 07/23/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Severe energy deficits during military operations, produced by significant increases in exercise and limited dietary intake, result in conditions that degrade lean body mass and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. METHODS We conducted a three-phase, proof-of-concept, single centre, randomised, double-blind, placebo-controlled trial (CinicalTrials.gov, NCT02734238) of non-obese men: 14-d run-in, free-living, eucaloric diet phase; 28-d live-in, 55% exercise- and diet-induced energy deficit phase with (200 mg testosterone enanthate per week, Testosterone, n = 24) or without (Placebo, n = 26) exogenous testosterone; and 14-d recovery, free-living, ad libitum diet phase. Body composition was the primary end point; secondary endpoints included lower-body muscle function and health-related biomarkers. FINDINGS Following energy deficit, lean body mass increased in Testosterone and remained stable in Placebo, such that lean body mass significantly differed between groups [mean difference between groups (95% CI), 2.5 kg (3.3, 1.6); P < .0001]. Fat mass decreased similarly in both treatment groups [0.2 (-0.4, 0.7), P = 1]. Change in lean body mass was associated with change in total testosterone (r = 0.71, P < .0001). Supplemental testosterone had no effect on lower-body muscle function or health-related biomarkers. INTERPRETATION Findings suggest that supplemental testosterone may increase lean body mass during short-term severe energy deficit in non-obese, young men, but it does not appear to attenuate lower-body functional decline. FUNDING Collaborative Research to Optimize Warfighter Nutrition projects I and II, Joint Program Committee-5, funded by the US Department of Defence.
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Helms ER, Prnjak K, Linardon J. Towards a Sustainable Nutrition Paradigm in Physique Sport: A Narrative Review. Sports (Basel) 2019; 7:sports7070172. [PMID: 31315180 PMCID: PMC6681103 DOI: 10.3390/sports7070172] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/02/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022] Open
Abstract
Physique athletes strive for low body fat with high lean mass and have higher body image and eating disorder rates than the general population, and even other weightlifting populations. Whether athletes with a background or tendency to develop these issues are drawn to the sport, or whether it drives these higher incidences, is unknown. However, the biological drive of cyclical energy restriction may contribute to binge-eating behavior. Additionally, requisite monitoring, manipulation, comparison, and judgement of one's physique may contribute to body image concerns. Contest preparation necessitates manipulating body composition through energy restriction and increased expenditure, requiring dietary restraint and nutrition, exercise, and physique assessment. Thus, competitors are at mental health risk due to (1) pre-existing or predispositions to develop body image or eating disorders; (2) biological effects of energy restriction on eating psychology; and (3) dietary restraint attitudes and resultant physique, exercise, and nutrition monitoring behavior. In our narrative review we cover each factor, concluding with tentative best-practice recommendations, including dietary flexibility, slower weight loss, structured monitoring, gradual returns to offseason energy intakes, internal eating cues, appropriate offseason body compositions, and support from nutrition and mental health professionals. A mental health focus is a needed paradigm shift in bodybuilding nutrition practice and research.
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Affiliation(s)
- Eric R Helms
- Sports Performance Research Institute New Zealand (SPRINZ), Faculty of Health and Environmental Science, Auckland University of Technology, Private Bag 92006, Auckland 1142, New Zealand.
| | - Katarina Prnjak
- Sports Performance Research Institute New Zealand (SPRINZ), Faculty of Health and Environmental Science, Auckland University of Technology, Private Bag 92006, Auckland 1142, New Zealand
| | - Jake Linardon
- School of Psychology, Deakin University, 1 Gheringhap Street, Geelong, VIC 3220, Australia
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Grannell A, De Vito G, Murphy JC, le Roux CW. The influence of skeletal muscle on appetite regulation. Expert Rev Endocrinol Metab 2019; 14:267-282. [PMID: 31106601 DOI: 10.1080/17446651.2019.1618185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/09/2019] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Fat-free mass, of which skeletal muscle is amajor component, correlates positively with energy intake at energy balance. This is due to the effects of metabolically active tissue on energy expenditure which in itself appears to signal to the brain adrive to eat to ensure cellular energy homeostasis. The mechanisms responsible for this drive to eat are unknown but are likely to be related to energy utilization. Here muscle imparts an indirect influence on hunger. The drive to eat is also enhanced after muscle loss secondary to intentional weight loss. The evidence suggests loss of both fat mass and skeletal muscle mass directly influences the trajectory and magnitude of weight regain highlighting their potential role in long-termappetite control. The mechanisms responsible for the potential direct drive to eat stemming from muscle loss are unknown. AREAS COVERED The literature pertaining to muscle and appetite at energy balance and after weight loss was examined. Aliterature search was conducted to identify studies related to appetite, muscle, exercise, and weight loss. EXPERT OPINION Understanding the mechanisms which link energy expenditure and muscle loss to hunger has the potential to positively impact both the prevention and the treatment of obesity.
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Affiliation(s)
- Andrew Grannell
- a Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences , University College Dublin , Dublin , Ireland
- b MedFit Proactive Healthcare, Blackrock , Dublin , Ireland
| | - Giuseppe De Vito
- c School of Public Health, Physiotherapy and Sports Science , University College Dublin , Dublin , Ireland
| | - John C Murphy
- b MedFit Proactive Healthcare, Blackrock , Dublin , Ireland
| | - Carel W le Roux
- a Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences , University College Dublin , Dublin , Ireland
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Wheatley SD, Whitaker MJG. Why do people overeat? Hunger, psychological eating and type 2 diabetes. PRACTICAL DIABETES 2019. [DOI: 10.1002/pdi.2232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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40
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Bellissimo MP, Licata AD, Nucci A, Thompson W, Benardot D. Relationships Between Estimated Hourly Energy Balance and Body Composition in Professional Cheerleaders. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s42978-019-0004-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Case Study: Extreme Weight Making Causes Relative Energy Deficiency, Dehydration, and Acute Kidney Injury in a Male Mixed Martial Arts Athlete. Int J Sport Nutr Exerc Metab 2019; 29:331-338. [DOI: 10.1123/ijsnem.2018-0029] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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42
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Metabolic adaptations during negative energy balance and their potential impact on appetite and food intake. Proc Nutr Soc 2019; 78:279-289. [DOI: 10.1017/s0029665118002811] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This review examines the metabolic adaptations that occur in response to negative energy balance and their potential putative or functional impact on appetite and food intake. Sustained negative energy balance will result in weight loss, with body composition changes similar for different dietary interventions if total energy and protein intake are equated. During periods of underfeeding, compensatory metabolic and behavioural responses occur that attenuate the prescribed energy deficit. While losses of metabolically active tissue during energy deficit result in reduced energy expenditure, an additional down-regulation in expenditure has been noted that cannot be explained by changes in body tissue (e.g. adaptive thermogenesis). Sustained negative energy balance is also associated with an increase in orexigenic drive and changes in appetite-related peptides during weight loss that may act as cues for increased hunger and food intake. It has also been suggested that losses of fat-free mass (FFM) could also act as an orexigenic signal during weight loss, but more data are needed to support these findings and the signalling pathways linking FFM and energy intake remain unclear. Taken together, these metabolic and behavioural responses to weight loss point to a highly complex and dynamic energy balance system in which perturbations to individual components can cause co-ordinated and inter-related compensatory responses elsewhere. The strength of these compensatory responses is individually subtle, and early identification of this variability may help identify individuals that respond well or poorly to an intervention.
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McGinnis KD, McAdam JS, Lockwood CM, Young KC, Roberts MD, Sefton JM. Impact of Protein and Carbohydrate Supplementation on Musculoskeletal Injuries in Army Initial Entry Training Soldiers. Nutrients 2018; 10:nu10121938. [PMID: 30563273 PMCID: PMC6315558 DOI: 10.3390/nu10121938] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 11/16/2022] Open
Abstract
This project investigated whey protein and/or carbohydrate supplementation effects on musculoskeletal injury (MSI) outcomes. Four groups of Initial Entry Training soldiers consumed either: (1) one protein (38.6 g, 293 kcal); (2) one carbohydrate (63.4 g, 291 kcal); (3) two protein (77.2 g, 586 kcal); or (4) two carbohydrate servings/day (126.8 g, 582 kcal) after physical training and before bed, or before bed only. Odds Ratio, Chi-square and Wilcoxon ranked-sum test compared supplementation/no supplementation, number of servings, and protein/carbohydrate for MSI and limited/missed duty rates and limited/missed training days. Non-matched pairs group averages were compared to 2015/2016 historical data. Non-supplemented soldiers were approximately 5× more likely to sustain a MSI (χ2 = 58.48, p < 0.001) and 4× more likely to miss training (χ2 = 9.73, p = 0.003) compared to two servings. Non-supplemented soldiers missed five additional training days compared to two servings (W = 6059.5, p = 0.02). Soldiers consuming one serving were approximately 3× more likely to sustain a MSI than two servings (χ2 = 9.55, p = 0.002). There was no difference in limited/missed duty rates or limited/missed training days between consuming one or two servings. There was no difference between consuming one serving versus no supplementation or protein versus carbohydrate supplementation for any outcome variable. Soldiers consuming 2 servings/day of protein or carbohydrate had lower MSI rates, limited/missed duty rates, and limited/ missed training days compared to non-supplemented soldiers.
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Affiliation(s)
- Kaitlin D McGinnis
- Warrior Research Center, School of Kinesiology, Auburn University, 301 Wire Road, Auburn, AL 36849, USA.
| | - Jeremy S McAdam
- Warrior Research Center, School of Kinesiology, Auburn University, 301 Wire Road, Auburn, AL 36849, USA.
- UAB Center for Exercise Medicine, University of Alabama Birmingham, Birmingham, AL 35294, USA.
| | | | - Kaelin C Young
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL 36849, USA.
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Michael D Roberts
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - JoEllen M Sefton
- Warrior Research Center, School of Kinesiology, Auburn University, 301 Wire Road, Auburn, AL 36849, USA.
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HAMARSLAND HÅVARD, PAULSEN GØRAN, SOLBERG PAULA, SLAATHAUG OLEGUNNAR, RAASTAD TRULS. Depressed Physical Performance Outlasts Hormonal Disturbances after Military Training. Med Sci Sports Exerc 2018; 50:2076-2084. [DOI: 10.1249/mss.0000000000001681] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Relative Energy Deficiency in Sport in Male Athletes: A Commentary on Its Presentation Among Selected Groups of Male Athletes. Int J Sport Nutr Exerc Metab 2018; 28:364-374. [PMID: 30040508 DOI: 10.1123/ijsnem.2018-0182] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Low energy availability (LEA) is a key element of the Female Athlete Triad. Causes of LEA include failure to match high exercise energy expenditure (unintentional) or pathological behaviors of disordered eating (compulsive) and overzealous weight control programs (misguided but intentional). Recognition of such scenarios in male athletes contributed to the pronouncement of the more inclusive Relative Energy Deficiency in Sport (RED-S) syndrome. This commentary describes the insights and experience of the current group of authors around the apparently heightened risk of LEA in some populations of male athletes: road cyclists, rowers (lightweight and open weight), athletes in combat sports, distance runners, and jockeys. The frequency, duration, and magnitude of the LEA state appear to vary between populations. Common risk factors include cyclical management of challenging body mass and composition targets (including "making weight") and the high energy cost of some training programs or events that is not easily matched by energy intake. However, additional factors such as food insecurity and lack of finances may also contribute to impaired nutrition in some populations. Collectively, these insights substantiate the concept of RED-S in male athletes and suggest that a specific understanding of a sport, subpopulation, or culture may identify a complex series of factors that can contribute to LEA and the type and severity of its outcomes. This commentary provides a perspective on the range of risk factors that should be addressed in future surveys of RED-S in athletic populations and targeted for specific investigation and modification.
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Threshold of Energy Deficit and Lower-Body Performance Declines in Military Personnel: A Meta-Regression. Sports Med 2018; 48:2169-2178. [DOI: 10.1007/s40279-018-0945-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Negative Consequences of Low Energy Availability in Natural Male Bodybuilding: A Review. Int J Sport Nutr Exerc Metab 2018; 28:385-402. [PMID: 28530498 DOI: 10.1123/ijsnem.2016-0332] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Energy availability (EA) is a scientific concept describing how much energy is available for basic metabolic functions such as reproduction, immunity, and skeletal homeostasis. Carefully controlled studies on women have shown pathological effects of EA < 30 kcal/kg fat-free mass (FFM), and this state has been labeled low EA (LEA). Bodybuilding is a sport in which athletes compete to show muscular definition, symmetry, and low body fat (BF). The process of contest preparation in bodybuilding includes months of underfeeding, thus increasing the risk of LEA and its negative health consequences. As no well-controlled studies have been conducted in natural male bodybuilders on effects of LEA, the aim of this review was to summarize what can be extrapolated from previous relevant research findings in which EA can be calculated. The reviewed literature indicates that a prolonged EA < 25 kcal/kg FFM results in muscle loss, hormonal imbalances, psychological problems, and negatively affects the cardiovascular system when approaching the lower limits of BF (∼4%-5%) among males. Case studies on natural male bodybuilders who prepare for contest show muscle loss (>40% of total weight loss) with EA < 20 kcal/kg FFM, and in the study with the lowest observed BF (∼4 kg), major mood disturbance and hormonal imbalances co-occurred. Studies also underline the problem of BF overshoot during refeeding after extremes of LEA among males. A more tempered approach (EA > 25 kcal/kg FFM) might result in less muscle loss among natural male bodybuilders who prepare for contest, but more research is needed.
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Dulloo AG, Miles-Chan JL, Schutz Y. Collateral fattening in body composition autoregulation: its determinants and significance for obesity predisposition. Eur J Clin Nutr 2018; 72:657-664. [PMID: 29559726 PMCID: PMC5945583 DOI: 10.1038/s41430-018-0138-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 02/10/2018] [Indexed: 11/09/2022]
Abstract
Collateral fattening refers to the process whereby excess fat is deposited as a result of the body’s attempt to counter a deficit in lean mass through overeating. Its demonstration and significance to weight regulation and obesity can be traced to work on energy budget strategies in growing mammals and birds, and to men recovering from experimental starvation. The cardinal features of collateral fattening rests upon (i) the existence of a feedback system between lean tissue and appetite control, with lean tissue deficit driving hyperphagia, and (ii) upon the occurrence of a temporal desynchronization in the recovery of body composition, with complete recovery of fat mass preceeding that of lean mass. Under these conditions, persistent hyperphagia driven by the need to complete the recovery of lean tissue will result in the excess fat deposition (hence collateral fattening) and fat overshooting. After reviewing the main lines of evidence for the phenomenon of collateral fattening in body composition autoregulation, this article discusses the causes and determinants of the desynchronization in fat and lean tissue recovery leading to collateral fattening and fat overshooting, and points to their significance in the mechanisms by which dieting, developmental programming and sedentariness predispose to obesity.
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Affiliation(s)
- Abdul G Dulloo
- Department of Endocrinology, Metabolism and Cardiovascular System, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Jennifer L Miles-Chan
- Department of Endocrinology, Metabolism and Cardiovascular System, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Yves Schutz
- Department of Endocrinology, Metabolism and Cardiovascular System, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
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Karl JP, Margolis LM, Murphy NE, Carrigan CT, Castellani JW, Madslien EH, Teien HK, Martini S, Montain SJ, Pasiakos SM. Military training elicits marked increases in plasma metabolomic signatures of energy metabolism, lipolysis, fatty acid oxidation, and ketogenesis. Physiol Rep 2017; 5:e13407. [PMID: 28899914 PMCID: PMC5599865 DOI: 10.14814/phy2.13407] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/06/2017] [Accepted: 08/10/2017] [Indexed: 01/08/2023] Open
Abstract
Military training studies provide unique insight into metabolic responses to extreme physiologic stress induced by multiple stressor environments, and the impacts of nutrition in mediating these responses. Advances in metabolomics have provided new approaches for extending current understanding of factors modulating dynamic metabolic responses in these environments. In this study, whole-body metabolic responses to strenuous military training were explored in relation to energy balance and macronutrient intake by performing nontargeted global metabolite profiling on plasma collected from 25 male soldiers before and after completing a 4-day, 51-km cross-country ski march that produced high total daily energy expenditures (25.4 MJ/day [SD 2.3]) and severe energy deficits (13.6 MJ/day [SD 2.5]). Of 737 identified metabolites, 478 changed during the training. Increases in 88% of the free fatty acids and 91% of the acylcarnitines, and decreases in 88% of the mono- and diacylglycerols detected within lipid metabolism pathways were observed. Smaller increases in 75% of the tricarboxylic acid cycle intermediates, and 50% of the branched-chain amino acid metabolites detected were also observed. Changes in multiple metabolites related to lipid metabolism were correlated with body mass loss and energy balance, but not with energy and macronutrient intakes or energy expenditure. These findings are consistent with an increase in energy metabolism, lipolysis, fatty acid oxidation, ketogenesis, and branched-chain amino acid catabolism during strenuous military training. The magnitude of the energy deficit induced by undereating relative to high energy expenditure, rather than macronutrient intake, appeared to drive these changes, particularly within lipid metabolism pathways.
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - John W Castellani
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | | | | | - Svein Martini
- Norwegian Defense Research Establishment, Kjeller, Norway
| | - Scott J Montain
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Pasiakos SM, Berryman CE, Karl JP, Lieberman HR, Orr JS, Margolis LM, Caldwell JA, Young AJ, Montano MA, Evans WJ, Vartanian O, Carmichael OT, Gadde KM, Harris M, Rood JC. Physiological and psychological effects of testosterone during severe energy deficit and recovery: A study protocol for a randomized, placebo-controlled trial for Optimizing Performance for Soldiers (OPS). Contemp Clin Trials 2017; 58:47-57. [PMID: 28479217 DOI: 10.1016/j.cct.2017.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/27/2017] [Accepted: 05/03/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND The physiological consequences of severe energy deficit include hypogonadism and the loss of fat-free mass. Prolonged energy deficit also impacts physical performance, mood, attentiveness, and decision-making capabilities. This study will determine whether maintaining a eugonadal state during severe, sustained energy deficit attenuates physiological decrements and maintains mental performance. This study will also assess the effects of normalizing testosterone levels during severe energy deficit and recovery on gut health and appetite regulation. METHODS Fifty physically active men will participate in a 3-phase, randomized, placebo-controlled study. After completing a 14-d, energy-adequate, diet acclimation phase (protein: 1.6g∙kg-1∙d-1; fat: 30% total energy intake), participants will be randomized to undergo a 28-d, 55% energy deficit phase with (DEF+TEST: 200mg testosterone enanthate per week) or without (DEF) exogenous testosterone. Diet and physical activity will be rigorously controlled. Recovery from the energy deficit (ad libitum diet, no testosterone) will be assessed until body mass has been recovered within ±2.5% of initial body mass. Body composition, stable isotope methodologies, proteomics, muscle biopsies, whole-room calorimetry, molecular biology, activity/sleep monitoring, personality and cognitive function assessments, functional MRI, and comprehensive biochemistries will be used to assess physiological and psychological responses to energy restriction and recovery feeding while volunteers are in an expected hypogonadal versus eugonadal state. DISCUSSION The Optimizing Performance for Soldiers (OPS) study aims to determine whether preventing hypogonadism will mitigate declines in physical and mental function that typically occur during prolonged energy deficit, and the efficacy of testosterone replacement on recovery from severe underfeeding. TRIAL REGISTRATION NCT02734238.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.
| | - Claire E Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA.
| | - J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.
| | - Jeb S Orr
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.
| | - Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.
| | - John A Caldwell
- Oak Ridge Institute for Science and Education, Belcamp, MD, USA
| | - Andrew J Young
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA.
| | | | - William J Evans
- University of California at Berkeley, Berkeley, CA, USA; Duke University, Durham, NC, USA.
| | - Oshin Vartanian
- Oak Ridge Institute for Science and Education, Belcamp, MD, USA; Defence Research and Development Canada, University of Toronto, Canada.
| | | | - Kishore M Gadde
- Pennington Biomedical Research Center, Baton Rouge, LA, USA.
| | - Melissa Harris
- Pennington Biomedical Research Center, Baton Rouge, LA, USA.
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Baton Rouge, LA, USA.
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