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Dotan R. Children's V ˙ O 2 max trainability deficit: A quantitative analysis and a qualitative hypothesis. Eur J Appl Physiol 2025:10.1007/s00421-025-05778-2. [PMID: 40392270 DOI: 10.1007/s00421-025-05778-2] [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: 12/10/2024] [Accepted: 03/20/2025] [Indexed: 05/22/2025]
Abstract
BACKGROUND The response to training of children's maximal aerobic power ( V ˙ O2max/peak) has long been claimed to be significantly smaller than in adults and to be augmented by high-intensity training. Although several hypotheses have been put forth to explain children's lesser response, none has addressed both aspects, partly because a sufficiently large database for quantifying the phenomena and formulating a plausible hypothesis has not been established. PURPOSE To compile and analyze an unprecedentedly large literature database and use its findings to inform the formulation of a hypothesis for children's trainability deficit and its underlying causes. METHODS Cohort size, age, pre-training V ˙ O2max/peak, training intensity and duration, testing modality, and the training response were extracted from 650 training studies comprising 1046 experimental cohorts (children = 222, adults = 824), which were then compared between children and adults. RESULTS Children's mean overall V ˙ O2max training response was only 58% that of adults (p < 0.000001). High-intensity training was 25% more effective than low-moderate intensity in children (p = 0.041), but not in adults (-3.8%; NS). Nevertheless, children's high-intensity training was still only 67% as effective as in adults (p < 0.00001). INTERPRETATION AND HYPOTHESIS While some of the factors proposed to-date may account, in part, for children's trainability deficit, none has explained why high-intensity training is advantageous in children but not in adults. Presently, only child-adult differences in neuromuscular activation and muscle functional composition can, on their own or in conjunction with other factors, comprehensively account for all observations. An extensive body of evidence is presented in support of the hypothesis and data interpretation.
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Affiliation(s)
- Raffy Dotan
- Faculty of Applied Health Sciences, Brock University, St Catharines, ON, L2S 3A1, Canada.
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Quadri M, Ariza AJ, Tucker JM, Bea JW, King EC, Kirk S, Sweeney BR, Santos M, Silver L, Roberts KJ, Binns HJ. Percent Body Fat and Weight Status of Youth Participating in Pediatric Weight Management Programs in the Pediatric Obesity Weight Evaluation Registry. Child Obes 2025; 21:50-64. [PMID: 39187260 DOI: 10.1089/chi.2023.0201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Factors associated with change in percent body fat (%BF) of children in pediatric weight management (PWM) care may differ from those associated with change in weight status. Objective: To describe %BF and weight status at initial visits to 14 PWM sites, identify differences by sex, and evaluate factors associated with change over 6 months. Methods: Initial visits of 2496 males and 2821 females aged 5-18 years were evaluated. %BF was measured using bioelectrical impedance analysis. Results: Sex-specific logistic regressions [806 males (32.3%), 837 females (29.7%)] identified associations with primary outcomes: lower %BF and metabolically impactful ≥5-point drop in percent of the 95th BMI percentile (%BMIp95) over 6 months. At the initial visit, males had lower %BF and higher %BMIp95 than females. Over 6 months, males had significantly (p < 0.001) greater median drop in %BF (-1.4% vs. -0.4%) and %BMIp95 (-3.0% vs. -1.9%) and a higher frequency of decreased %BF (68.9% vs. 57.8%), but similar percentage with ≥5-point %BMIp95 drop (36.5% vs. 32.4%; p = 0.080). For males, factors significantly associated with decreased %BF (older age, ≥6 visits, lack of developmental or depression/anxiety concerns) were not related to having a ≥5-point %BMIp95 drop. For females, lack of depression/anxiety concern was significantly associated with decreased %BF but was not associated with ≥5-point %BMIp95 drop. Conclusions: There are differences by sex in initial visit %BF and %BMIp95 and in characteristics associated with changes in these measures. PWM interventions should consider evaluating body composition and sex-stratifying outcomes.
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Affiliation(s)
- Maheen Quadri
- Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Adolfo J Ariza
- Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jared M Tucker
- Helen DeVos Children's Hospital, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - Jennifer W Bea
- Department of Health Promotion Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Eileen C King
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Shelley Kirk
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
- The Heart Institute, Center for Better Health and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Brooke R Sweeney
- University of Missouri-Kansas City Children's Center for Healthy Lifestyles & Nutrition, Children's Mercy-Kansas City, Kansas City, MO, USA
| | | | - Lucie Silver
- Helen DeVos Children's Hospital, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - Karyn J Roberts
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Helen J Binns
- Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Woods S, McKiel A, Herda T, Klentrou P, Holmes M, Gabriel D, Falk B. Motor unit firing rates during slow and fast contractions in boys and men. Eur J Appl Physiol 2024; 124:2965-2979. [PMID: 38762834 DOI: 10.1007/s00421-024-05500-8] [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: 09/24/2023] [Accepted: 05/03/2024] [Indexed: 05/20/2024]
Abstract
BACKGROUND Motor unit (MU) activation during maximal contractions is lower in children compared with adults. Among adults, discrete MU activation differs, depending on the rate of contraction. We investigated the effect of contraction rate on discrete MU activation in boys and men. METHODS Following a habituation session, 14 boys and 20 men completed two experimental sessions for knee extension and wrist flexion, in random order. Maximal voluntary isometric torque (MVIC) was determined before completing trapezoidal isometric contractions (70%MVIC) at low (10%MVIC/s) and high (35%MVIC/s) contraction rates. Surface electromyography was captured from the vastus lateralis (VL) and flexor carpi radialis (FCR) and decomposed into individual MU action potential (MUAP) trains. RESULTS In both groups and muscles, the initial MU firing rate (MUFR) was greater (p < 0.05) at high compared with low contraction rates. The increase in initial MUFR at the fast contraction in the VL was greater in men than boys (p < 0.05). Mean MUFR was significantly lower during fast contractions only in the FCR (p < 0.05). In both groups and muscles, the rate of decay of MUFR with increasing MUAP amplitude was less steep (p < 0.05) during fast compared with slow contractions. CONCLUSION In both groups and muscles, initial MUFRs, as well as MUFRs of large MUs were higher during fast compared with slow contractions. However, in the VL, the increase in initial MUFR was greater in men compared with boys. This suggests that in large muscles, men may rely more on increasing MUFR to generate torque at faster rates compared with boys.
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Affiliation(s)
- Stacey Woods
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Andrew McKiel
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Trent Herda
- School of Education and Human Sciences, University of Kansas, Lawrence, KS, USA
| | - Panagiota Klentrou
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Michael Holmes
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - David Gabriel
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Bareket Falk
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
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4
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Handelsman DJ. Toward a Robust Definition of Sport Sex. Endocr Rev 2024; 45:709-736. [PMID: 38578952 DOI: 10.1210/endrev/bnae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 01/17/2024] [Accepted: 03/26/2024] [Indexed: 04/07/2024]
Abstract
Elite individual sports in which success depends on power, speed, or endurance are conventionally divided into male and female events using traditional binary definitions of sex. Male puberty creates durable physical advantages due to the 20- to 30-fold increase in circulating testosterone producing a sustained uplift in men's muscle, bone, hemoglobin, and cardiorespiratory function resulting from male puberty and sustained during men's lives. These male physical advantages provide strong justification for a separate protected category of female events allowing women to achieve the fame and fortune from success they would be denied if competing against men. Recent wider social acceptance of transgender individuals, together with the less recognized involvement of intersex individuals, challenge and threaten to defeat the sex classifications for elite individual female events. This can create unfair advantages if seeking inclusion into elite female events of unmodified male-bodied athletes with female gender identity who have gained the physical advantages of male puberty. Based on reproductive physiology, this paper proposes a working definition of sport sex based primarily on an individual's experience of male puberty and can be applied to transgender and various XY intersex conditions. Consistent with the multidimensionality of biological sex (chromosomal, genetic, hormonal, anatomical sex), this definition may be viewed as a multistrand cable whose overall strength survives when any single strand weakens or fails, rather than as a unidimensional chain whose strength is only as good as its weakest link.
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Affiliation(s)
- David J Handelsman
- Andrology Department, ANZAC Research Institute, University of Sydney, Concord Hospital, Syndey, NSW 2139, Australia
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Herda TJ, Holmes EA, Cleary CJ, Minor KT, Thyfault JP, Shook RP, Herda AA. Motor unit firing rates increase in prepubescent youth following linear periodization resistance exercise training. Eur J Appl Physiol 2024; 124:2675-2686. [PMID: 38634901 DOI: 10.1007/s00421-024-05455-w] [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: 10/11/2023] [Accepted: 02/29/2024] [Indexed: 04/19/2024]
Abstract
PURPOSE The purpose was to examine the effects of 8-weeks (3 days/week) of linear periodization resistance exercise training (RET) on neuromuscular function in prepubescent youth. METHODS Twenty-five healthy prepubescent youth (11 males, 14 females, age = 9.1 ± 0.8 years) completed the RET (n = 17) or served as controls (CON, n = 8). Isometric maximal voluntary contractions (MVCs) and trapezoidal submaximal contractions at 35 and 60% MVC of the right leg extensors were performed with surface electromyography (EMG) recorded from the leg extensors [vastus lateralis (VL), rectus femoris, and vastus medialis] and flexors (biceps femoris and semitendinosus). EMG amplitude of the leg extensors and flexors were calculated during the MVCs. Motor unit (MU) action potential trains were decomposed from the surface EMG of the VL for the 35 and 60% MVCs. MU firing rates and action potential amplitudes were regressed against recruitment threshold with the y-intercepts and slopes calculated for each contraction. Total leg extensor muscle cross-sectional area (CSA) was collected using ultrasound images. ANOVA models were used to examine potential differences. RESULTS Isometric strength increased post-RET (P = 0.006) with no changes in leg extensor and flexor EMG amplitude. Furthermore, there were no changes in total CSA or the MU action potential amplitude vs. recruitment threshold relationships. However, there were increases in the firing rates of the higher-threshold MUs post-RET as indicated with greater y-intercepts (P = 0.003) from the 60% MVC and less negative slope (P = 0.004) of the firing rates vs. recruitment threshold relationships at 35% MVC. CONCLUSIONS MU adaptations contribute to strength increases following RET in prepubescent youth.
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Affiliation(s)
- Trent J Herda
- Department of Health, Sport, and Exercise Science, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, 66045, KS, USA.
- Center for Children's Healthy Lifestyle and Nutrition, Kansas City, MO, USA.
| | - Elizabeth A Holmes
- Department of Health, Sport, and Exercise Science, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, 66045, KS, USA
| | - Christopher J Cleary
- Department of Health, Sport, and Exercise Science, University of Kansas-Edwards Campus, Overland Park, KS, USA
| | - Kelsey T Minor
- Department of Health, Sport, and Exercise Science, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, 66045, KS, USA
| | - John P Thyfault
- Department of Cell Biology and Physiology and Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA
- Center for Children's Healthy Lifestyle and Nutrition, Kansas City, MO, USA
| | - Robin P Shook
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA
- Center for Children's Healthy Lifestyle and Nutrition, Kansas City, MO, USA
| | - Ashley A Herda
- Department of Health, Sport, and Exercise Science, University of Kansas-Edwards Campus, Overland Park, KS, USA
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Gu T, Wang G, van den Oord EJC, Goldman E, Yang C, Xie N, Yao L, Wang CY, Jablonski M, Ray K, Liu F, Pan W, Flores G, Aleya L, Meng X, Jiao Y, Li M, Wang Y, Gu W. A Perspective on Evaluating Life Stage Differences in Drug Dosages for Drug Labeling and Instructions. AAPS J 2024; 26:95. [PMID: 39164430 DOI: 10.1208/s12248-024-00964-0] [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: 05/04/2024] [Accepted: 07/27/2024] [Indexed: 08/22/2024] Open
Abstract
Drug labeling and instructions provide essential information for patients regarding the usage of drugs. Instructions for the dosage of drug usage are critical for the effectiveness of the drug and the safety of patients. The dosage of many drugs varies depending on the patient's age. However, as our understanding of human biology deepens, we believe that these instructions need to be modified to incorporate different life stages. This is because human biology and metabolism differ significantly among different life stages, and their responses to drugs also vary. Additionally, the same age of different persons may fall into different life stages. Therefore, our group from multiple institutes and countries proposes a reexamination of whether incorporating life stages in all or any drug instructions will greatly enhance drug efficiency and patients' health.
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Affiliation(s)
- Tianshu Gu
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennesse, 38103, USA
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, PR China
| | - Guiying Wang
- General Surgery, The 2nd Hospital of Hebei Medical University, 215 Heping Road, Shijiazhuang, Hebei, China
| | - Edwin J C van den Oord
- Center for Biomarker Research and Precision Medicine (BPM), Virginia Commonwealth University, VCU Health Sciences Research Building, Room 216A, P. O. Box 980533, Richmond, Virgina, 23298-0581, USA
| | - Emanuel Goldman
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey, 07103, USA
| | - Chengyuan Yang
- Department of Orthopedic Surgery and BME-Campbell Clinic, University of Tennessee Health Science Centre, Memphis, Tennesse, 38163, USA
| | - Ning Xie
- College of Business, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Lan Yao
- Department of Orthopedic Surgery and BME-Campbell Clinic, University of Tennessee Health Science Centre, Memphis, Tennesse, 38163, USA
- College of Health Management, Harbin Medical University, 157 Baojian Road, Harbin, 150081, Heilongjiang, China
| | - Cong-Yi Wang
- The Centre for Biomedical Research, Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Respiratory Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Monica Jablonski
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, Tennesse, USA
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, Tennesse, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, Tennesse, USA
- College of Nursing, University of Tennessee Health Science Center, Memphis, Tennesse, 38105, USA
| | - Kunal Ray
- School of Biological Science, Ramkrishna Mission Vivekananda Education & Research Institute, Narendrapur, 700103, West Bengal, India
| | - Fengxia Liu
- Research Center, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - Wensen Pan
- Respiratory Medicine and Intensive Care, The 2, Hospital of Hebei Medical University, 215 Heping Road, Shijiazhuang, Hebei, China
| | - Gonzalo Flores
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, San Manuel, 72570, Puebla, Mexico
| | - Lotfi Aleya
- Chrono-Environnement Laboratory, UMR CNRS 6249, Bourgogne Franche-Comté University, 25030, Besançon Cedex, France
| | - Xia Meng
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, PR China
| | - Yan Jiao
- Department of Orthopedic Surgery and BME-Campbell Clinic, University of Tennessee Health Science Centre, Memphis, Tennesse, 38163, USA
| | - Minghui Li
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennesse, 38103, USA.
- , Memphis, USA.
| | - Yongjun Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, PR China.
- Department of Neurology and Department of Clinical Trial Center, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China.
| | - Weikuan Gu
- Department of Orthopedic Surgery and BME-Campbell Clinic, University of Tennessee Health Science Centre, Memphis, Tennesse, 38163, USA.
- Lt. Col. Luke Weathers, Jr. VA Medical Center, 116 N Pauline St., Memphis, Tennesse, 38105, USA.
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, 956 Court Avenue, Memphis, Tennesse, 38163, USA.
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Bim MA, de Pinto ADA, Claumann GS, Pelegrini A. Mediation effects of lean mass and fat mass on the relationship between body mass index and handgrip strength. Am J Hum Biol 2024; 36:e24004. [PMID: 37860994 DOI: 10.1002/ajhb.24004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/21/2023] Open
Abstract
OBJECTIVE This study aimed to assess the mediation effects of lean mass and fat mass on the relationship between body mass index (BMI) and handgrip strength (HGS) in adolescents. METHOD The sample included 118 adolescents (60 girls) aged 10-14 years. Body composition, determined from lean mass (LM) and fat mass (FM), was measured by dual-energy x-ray absorptiometry. HGS was measured using a digital dynamometer. Moderate-to-vigorous physical activity and sexual maturation, treated as covariates, were evaluated by accelerometry and pubic hair development, respectively. Spearman correlation and simple mediation analysis were used for statistical analysis. RESULTS A positive relationship was observed between BMI and HGS (rho = .364, p < .001), BMI and LM (rho = .466, p < .001), LM and HGS (rho = .784, p < .001), BMI and FM (rho = .907, p < .001), and FM and HGS (rho = .291, p = .001). LM was the only significant mediator of the relationship between BMI and HGS. CONCLUSION Only LM mediated the association between BMI and HGS, almost entirely explaining the relationship. The findings reinforce the need to include LM measurements in routine strength testing. Furthermore, strategies focused on LM development may be promising in preventing low muscle strength in adolescents.
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Affiliation(s)
- Mateus Augusto Bim
- Health and Sports Sciences Center, Department of Physical Education, State University of Santa Catarina, Florianópolis, Brazil
| | | | - Gaia Salvador Claumann
- Health and Sports Sciences Center, Department of Physical Education, State University of Santa Catarina, Florianópolis, Brazil
| | - Andreia Pelegrini
- Health and Sports Sciences Center, Department of Physical Education, State University of Santa Catarina, Florianópolis, Brazil
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Sudlow A, Galantine P, Del Sordo G, Raymond JJ, Dalleau G, Peyrot N, Duché P. Influence of Growth, Maturation, and Sex on Maximal Power, Force, and Velocity During Overground Sprinting. J Strength Cond Res 2024; 38:491-500. [PMID: 38416445 DOI: 10.1519/jsc.0000000000004645] [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: 02/29/2024]
Abstract
ABSTRACT Sudlow, A, Galantine, P, Del Sordo, G, Raymond, J-J, Dalleau, G, Peyrot, N, and Duché, P. Influence of growth, maturation, and sex on maximal power, force, and velocity during overground sprinting. J Strength Cond Res 38(3): 491-500, 2024-In pediatric populations maximal anaerobic power, force, and velocity capabilities are influenced by changes in body dimensions and muscle function. The aim of this study was to investigate the influences of growth, maturation, and sex on short-term anaerobic performance. One hundred forty children pre-, mid-, and postpeak height velocity performed two 30-m sprints concurrently measured using a radar device. Maximal power (Pmax), force (F0), and velocity (v0) were calculated from sprint velocity-time data and normalized using sex-specific, multiplicative, allometric models containing body mass, fat-free mass (FFM), or height, and chronological age. Absolute values for Pmax, F0, and v0 were higher with increasing maturity (p < 0.01; d ≥ 0.96), and boys had greater outputs than girls (p < 0.01; d ≥ 1.19). When Pmax and v0 were scaled all maturity-related and sex-related differences were removed. When F0 was scaled using models excluding age, all maturity-related differences were removed except for the least mature group (p < 0.05; d ≥ 0.88) and boys maintained higher values than girls (p < 0.05; d ≥ 0.92). All maturity-related and sex-related differences were removed when F0 was scaled using models including age. Maturity-related and sex-related variance in Pmax and v0 can be entirely explained when FFM, height, and chronological age are accounted for. Regarding F0, there seems to be a threshold after which the inclusion of age is no longer necessary to account for maturity-related differences. In young prepubertal children, the inclusion of age likely accounts for deficits in neuromuscular capacities and motor skills, which body dimensions cannot account for. Practitioners should focus on eliciting neural adaptations and enhancing motor coordination in prepubertal children to improve anaerobic performance during overground sprinting.
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Affiliation(s)
- Anthony Sudlow
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Paul Galantine
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Giovanna Del Sordo
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Jean-Jacques Raymond
- Sports Medicine and Traumatology Unit, Hôpital Sainte Musse, CHITS, Toulon, France
| | - Georges Dalleau
- Laboratory IRISSE, EA4075, University of La Réunion, Le Tampon, La Réunion
| | - Nicolas Peyrot
- Laboratory of Movement-Interactions-Performance, MIP, EA4334, University of Le Mans, Le Mans, France
| | - Pascale Duché
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
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Martakis K, Alexy U, Stark C, Hahn A, Rawer R, Duran I, Schönau E. Jumping Mechanography: Reference Centiles in Childhood and Introduction of the Nerve-Muscle Index to Quantify Motor Efficiency. J Clin Med 2023; 12:5984. [PMID: 37762925 PMCID: PMC10531761 DOI: 10.3390/jcm12185984] [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: 07/11/2023] [Revised: 09/06/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Jumping mechanography provides robust motor function indicators among children. The study aim was to develop centiles for the single 2-leg jump (S2LJ) in German children and adolescents and to identify differences in children with obesity. Data were collected in 2004-2021 through the German DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. All participants (6-18 years, mean age 11.4) performed annually an S2LJ aiming for maximum height on a Ground Reaction Force Platform. LMS (lambda-mu-sigma), including resampling, was used to develop centiles for velocity (vmax), jump height (hmax), relative force (Fmax/BW), relative power (Pmax/mass), impulse asymmetry and a new parameter to describe jump efficiency, the Nerve-Muscle Index (NMI), defined as vmax/(Fmax/BW). Data from 882 children and adolescents were analyzed (3062 measurements, median 3 per individual). In females, Fmax/BW values were higher in younger age but remained constant in adolescence. vmax, hmax and Pmax/mass increased in childhood, reaching a plateau in adolescence. In males, vmax, hmax and Pmax/mass showed a constant increase and the Fmax/BW remained lower. Children with obesity showed lower Fmax/BW, hmax, vmax and the NMI, hence, lower velocity per relative force unit and less efficient jump. The centiles should be used to monitor motor development in childhood. The NMI is a surrogate for motor efficiency.
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Affiliation(s)
- Kyriakos Martakis
- Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany; (K.M.)
- Department of Pediatric Neurology, Justus-Liebig-University Giessen, Feulgen Str. 10-12, 35392 Giessen, Germany
| | - Ute Alexy
- Department of Nutritional Epidemiology, Institute of Nutritional and Food Science, University of Bonn, 53115 Bonn, Germany;
| | - Christina Stark
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany;
| | - Andreas Hahn
- Department of Pediatric Neurology, Justus-Liebig-University Giessen, Feulgen Str. 10-12, 35392 Giessen, Germany
| | | | - Ibrahim Duran
- Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany; (K.M.)
- Center of Prevention and Rehabilitation, UniReha, Faculty of Medicine and University Hospital Cologne, Lindenburger Allee 44, 50931 Cologne, Germany
| | - Eckhard Schönau
- Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany; (K.M.)
- Center of Prevention and Rehabilitation, UniReha, Faculty of Medicine and University Hospital Cologne, Lindenburger Allee 44, 50931 Cologne, Germany
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WOODS STACEY, O’MAHONEY CARAGH, MAYNARD JAMES, DOTAN RAFFY, TENENBAUM GERSHON, FILHO EDSON, FALK BAREKET. Increase in Volitional Muscle Activation from Childhood to Adulthood: A Systematic Review and Meta-analysis. Med Sci Sports Exerc 2022; 54:789-799. [PMID: 34967802 PMCID: PMC9012528 DOI: 10.1249/mss.0000000000002853] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Children's maximal muscle strength is consistently lower than adults', even when normalized to body size. Lower volitional muscle activation (VA) in children is often considered one of the main reasons for age-related differences in muscular performance. However, some recent studies have reported similar VA in children and adults, bringing into question whether there is indeed an age-related increase in VA. The purpose of this review was to determine the effect of age on VA during maximal isometric contractions. METHODS Literature examining VA differences, using twitch interpolation in children (7-14 yr) and adults (16-28 yr), was systematically reviewed. Of the 1915 studies initially identified, 19 data sets were eligible for inclusion in the qualitative analysis and 14 in the quantitative meta-analysis (comprising 207 children and 193 adults). RESULTS Significantly lower VA in children was reported in 9/19 (47%) studies. A random-effects meta-analysis found a strong effect of age on VA, supporting lower VA in children compared with adults (Hedges' g = 1.55; confidence interval: 0.9-2.13). Moderator analysis included muscle group, sex, children's age, stimulation number (singlet, multiple), type (electric, magnetic), and location (muscle, nerve), of which only muscle group was significant (P < 0.001). A significant Egger's regression test and asymmetrical funnel plot suggest that publication bias may be present. CONCLUSIONS Overall, these findings suggest that compared with adults, children activate their motor-unit pool less compared with adults. Moreover, that the degree of VA increase with age may be influenced by the muscle examined (upper vs lower extremity). However, more research is needed to elucidate the influence of this possible factor, as the current review contains limited data from upper body muscles. The developmental mechanism responsible for children's lower VA requires further research.
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Affiliation(s)
- STACEY WOODS
- Department of Kinesiology, Brock University, St. Catharines, ON, CANADA
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, CANADA
| | - CARAGH O’MAHONEY
- Department of Kinesiology, Brock University, St. Catharines, ON, CANADA
| | - JAMES MAYNARD
- Department of Kinesiology, Brock University, St. Catharines, ON, CANADA
| | - RAFFY DOTAN
- Department of Kinesiology, Brock University, St. Catharines, ON, CANADA
| | - GERSHON TENENBAUM
- B. Ivcher School of Psychology, Reichman University, Herzliya, ISRAEL
| | - EDSON FILHO
- Wheelock College of Education and Human Development, Boston University, Boston, MA
| | - BAREKET FALK
- Department of Kinesiology, Brock University, St. Catharines, ON, CANADA
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, CANADA
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