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Willems MET, Bray PW, Bassett HM, Spurr TJ, West AT. Effects of CurraNZ, a New Zealand Blackcurrant Extract during 1 Hour of Treadmill Running in Female and Male Marathon des Sables Athletes in Hot Conditions: Two Case Studies. J Funct Morphol Kinesiol 2024; 9:76. [PMID: 38651434 PMCID: PMC11036262 DOI: 10.3390/jfmk9020076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 04/25/2024] Open
Abstract
Four weeks before competition in the 2023 Marathon des Sables, a 6-stage, ~250 km running event in the Sahara Desert, we examined the effects of a 7-day intake of New Zealand blackcurrant extract (210 mg anthocyanins per day) on 1 h treadmill running-induced physiological and metabolic responses in the heat (~34 °C, relative humidity: ~30%) in non-acclimatized amateur female and male athletes (age: 23, 38 yrs, BMI: 24.2, 28.4 kg·m-2, body fat%: 29.2, 18.8%, V˙O2max: 50.1, 52.1 mL·kg-1·min-1). During the 1 h run at 50%V˙O2max (speed female: 7.3, male: 7.5 km·h-1), indirect calorimetry was used, and heart rate was recorded at 15 min intervals with core temperature monitoring (0.05 Hz). The 1 h runs took place 3 h after a light breakfast and 2 h after intake of the final dose of New Zealand blackcurrant extract with water allowed ad libitum during the run. The New Zealand blackcurrant extract had no effects on the female athlete. The respiratory exchange ratio (RER) of the female athlete in the non-supplement control condition was 0.77 ± 0.01, indicating an existing ~77% contribution of fat oxidation to the energy requirements. In the male athlete, during 1 h of running, fat oxidation was higher by 21% (p < 0.01), carbohydrate oxidation was 31% lower (p = 0.05), RER was 0.03 units lower (p = 0.04), and core temperature was 0.4 °C lower (p < 0.01) with no differences for heart rate, minute ventilation, oxygen uptake, and carbon dioxide production for the New Zealand blackcurrant condition compared to the non-supplement control condition. Seven-day intake of New Zealand blackcurrant extract (210 mg anthocyanins per day) provided beneficial physiological and metabolic responses during exertional heat stress by 1 h of indoor (~34 °C) treadmill running in a male Marathon des Sables athlete 4 weeks before competition. Future work is required to address whether New Zealand blackcurrant provides a nutritional ergogenic effect for Marathon des Sables athletes during long-duration running in the heat combined with personalized nutrition.
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Affiliation(s)
- Mark E. T. Willems
- Institute of Applied Sciences, University of Chichester, College Lane, Chichester PO19 6PE, UK; (P.W.B.); (H.M.B.); (T.J.S.); (A.T.W.)
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Running-Induced Metabolic and Physiological Responses Using New Zealand Blackcurrant Extract in a Male Ultra-Endurance Runner: A Case Study. J Funct Morphol Kinesiol 2022; 7:jfmk7040104. [PMID: 36547650 PMCID: PMC9787938 DOI: 10.3390/jfmk7040104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/14/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Physical training for ultra-endurance running provides physiological adaptations for exercise-induced substrate oxidation. We examined the effects of New Zealand blackcurrant (NZBC) extract on running-induced metabolic and physiological responses in a male amateur ultra-endurance runner (age: 40 years, body mass: 65.9 kg, BMI: 23.1 kg·m−2, body fat: 14.7%, V˙O2max: 55.3 mL·kg−1·min−1, resting heart rate: 45 beats·min−1, running history: 6 years, marathons: 20, ultra-marathons: 28, weekly training distance: ~80 km, weekly running time: ~9 h). Indirect calorimetry was used and heart rate recorded at 15 min intervals during 120 min of treadmill running (speed: 10.5 km·h−1, 58% V˙O2max) in an environmental chamber (temperature: ~26 °C, relative humidity: ~70%) at baseline and following 7 days intake of NZBC extract (210 mg of anthocyanins·day−1) with constant monitoring of core temperature. The male runner had unlimited access to water and consumed a 100-kcal energy gel at 40- and 80 min during the 120 min run. There were no differences (mean of 8, 15 min measurements) for minute ventilation, oxygen uptake, carbon dioxide production and core temperature. With NZBC extract, the respiratory exchange ratio was 0.02 units lower, carbohydrate oxidation was 11% lower and fat oxidation was 23% higher (control: 0.39 ± 0.08, NZBC extract: 0.48 ± 0.12 g·min−1, p < 0.01). Intake of the energy gel did not abolish the enhanced fat oxidation by NZBC extract. Seven days’ intake of New Zealand blackcurrant extract altered exercise-induced substrate oxidation in a male amateur ultra-endurance runner covering a half-marathon distance in 2 h. More studies are required to address whether intake of New Zealand blackcurrant extract provides a nutritional ergogenic effect for ultra-endurance athletes to enhance exercise performance.
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Miller GD, Collins S, Ives J, Williams A, Basu S, Kim-Shapiro DB, Berry MJ. Efficacy and Variability in Plasma Nitrite Levels during Long-Term Supplementation with Nitrate Containing Beetroot Juice. J Diet Suppl 2022; 20:885-910. [PMID: 36310089 PMCID: PMC10148922 DOI: 10.1080/19390211.2022.2137269] [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] [Indexed: 01/16/2023]
Abstract
Long-term consumption of beetroot juice on efficacy of converting dietary nitrate to plasma nitrate and nitrite was investigated. Adults were randomized to consume either beetroot juice with 380 mg of nitrate (BR) or a beetroot juice placebo (PL) for 12-weeks. Plasma nitrate and nitrite were measured before and 90-minutes after consuming their intervention beverage. Percent change in nitrite across the 90 min was greater in BR (273.2 ± 39.9%) vs. PL (4.9 ± 36.9%). Long-term consumption of nitrate containing beetroot juice increased fasting nitrate and nitrite plasma levels compared to baseline.
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Affiliation(s)
- Gary D. Miller
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC. 27109
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109
| | - Summer Collins
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC. 27109
| | - James Ives
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC. 27109
| | - Allie Williams
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC. 27109
| | - Swati Basu
- Department of Physics, Wake Forest University, Winston-Salem, NC. 27109
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109
| | - Daniel B. Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC. 27109
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109
| | - Michael J. Berry
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC. 27109
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109
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Gentilin A, Zanini P, Cevese A, Schena F, Tarperi C. Ergogenic effects of citrulline supplementation on exercise performance and physiological indexes of exercise performance during cycling tests: A review. Sci Sports 2022. [DOI: 10.1016/j.scispo.2021.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Proctor DN, Neely KA, Mookerjee S, Tucker J, Somani YB, Flanagan M, Kim-Shapiro DB, Basu S, Muller MD, Jin-Kwang Kim D. Inorganic nitrate supplementation and blood flow restricted exercise tolerance in post-menopausal women. Nitric Oxide 2022; 122-123:26-34. [PMID: 35240317 PMCID: PMC9062890 DOI: 10.1016/j.niox.2022.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/12/2022] [Accepted: 02/25/2022] [Indexed: 11/17/2022]
Abstract
Exercise tolerance appears to benefit most from dietary nitrate (NO3-) supplementation when muscle oxygen (O2) availability is low. Using a double-blind, randomized cross-over design, we tested the hypothesis that acute NO3- supplementation would improve blood flow restricted exercise duration in post-menopausal women, a population with reduced endogenous nitric oxide bioavailability. Thirteen women (57-76 yr) performed rhythmic isometric handgrip contractions (10% MVC, 30 per min) during progressive forearm blood flow restriction (upper arm cuff gradually inflated 20 mmHg each min) on three study visits, with 7-10 days between visits. Approximately one week following the first (familiarization) visit, participants consumed 140 ml of NO3- concentrated (9.7 mmol, 0.6 gm NO3-) or NO3-depleted beetroot juice (placebo) on separate days (≥7 days apart), with handgrip exercise beginning 100 min post-consumption. Handgrip force recordings were analyzed to determine if NO3- supplementation enhanced force development as blood flow restriction progressed. Nitrate supplementation increased plasma NO3- (16.2-fold) and NO2- (4.2-fold) and time to volitional fatigue (61.8 ± 56.5 s longer duration vs. placebo visit; p = 0.03). Nitrate supplementation increased the rate of force development as forearm muscle ischemia progressed (p = 0.023 between 50 and 75% of time to fatigue) with non-significant effects thereafter (p = 0.052). No effects of nitrate supplementation were observed for mean duration of contraction or relaxation rates (all p > 0.150). These results suggest that acute NO3- supplementation prolongs time-to-fatigue and speeds grip force development during progressive forearm muscle ischemia in postmenopausal women.
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Affiliation(s)
- David N Proctor
- Penn State University, University Park, PA, USA; Penn State College of Medicine, Hershey, PA, USA.
| | | | | | | | | | - Michael Flanagan
- Penn State College of Medicine, Hershey, PA, USA; Penn State Health Family and Community Medicine, University Park, PA, USA
| | | | - Swati Basu
- Wake Forest University, Winston-Salem, NC, USA
| | - Matthew D Muller
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Danielle Jin-Kwang Kim
- Penn State University, University Park, PA, USA; Penn State College of Medicine, Hershey, PA, USA
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Kreider RB, Jäger R, Purpura M. Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review. Nutrients 2022; 14:nu14051035. [PMID: 35268011 PMCID: PMC8912867 DOI: 10.3390/nu14051035] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/12/2022] Open
Abstract
In 2011, we published a paper providing an overview about the bioavailability, efficacy, and regulatory status of creatine monohydrate (CrM), as well as other “novel forms” of creatine that were being marketed at the time. This paper concluded that no other purported form of creatine had been shown to be a more effective source of creatine than CrM, and that CrM was recognized by international regulatory authorities as safe for use in dietary supplements. Moreover, that most purported “forms” of creatine that were being marketed at the time were either less bioavailable, less effective, more expensive, and/or not sufficiently studied in terms of safety and/or efficacy. We also provided examples of several “forms” of creatine that were being marketed that were not bioavailable sources of creatine or less effective than CrM in comparative effectiveness trials. We had hoped that this paper would encourage supplement manufacturers to use CrM in dietary supplements given the overwhelming efficacy and safety profile. Alternatively, encourage them to conduct research to show their purported “form” of creatine was a bioavailable, effective, and safe source of creatine before making unsubstantiated claims of greater efficacy and/or safety than CrM. Unfortunately, unsupported misrepresentations about the effectiveness and safety of various “forms” of creatine have continued. The purpose of this critical review is to: (1) provide an overview of the physiochemical properties, bioavailability, and safety of CrM; (2) describe the data needed to substantiate claims that a “novel form” of creatine is a bioavailable, effective, and safe source of creatine; (3) examine whether other marketed sources of creatine are more effective sources of creatine than CrM; (4) provide an update about the regulatory status of CrM and other purported sources of creatine sold as dietary supplements; and (5) provide guidance regarding the type of research needed to validate that a purported “new form” of creatine is a bioavailable, effective and safe source of creatine for dietary supplements. Based on this analysis, we categorized forms of creatine that are being sold as dietary supplements as either having strong, some, or no evidence of bioavailability and safety. As will be seen, CrM continues to be the only source of creatine that has substantial evidence to support bioavailability, efficacy, and safety. Additionally, CrM is the source of creatine recommended explicitly by professional societies and organizations and approved for use in global markets as a dietary ingredient or food additive.
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Affiliation(s)
- Richard B. Kreider
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA
- Correspondence: ; Tel.: +1-972-458-1498
| | - Ralf Jäger
- Increnovo LLC, Milwaukee, WI 53202, USA; (R.J.); (M.P.)
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Auditing the Representation of Female Versus Male Athletes in Sports Science and Sports Medicine Research: Evidence-Based Performance Supplements. Nutrients 2022; 14:nu14050953. [PMID: 35267928 PMCID: PMC8912470 DOI: 10.3390/nu14050953] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 12/13/2022] Open
Abstract
Although sports nutrition guidelines promote evidence-based practice, it is unclear whether women have been adequately included in the underpinning research. In view of the high usage rates of performance supplements by female athletes, we conducted a standardised audit of the literature supporting evidence-based products: β-alanine, caffeine, creatine, glycerol, nitrate/beetroot juice and sodium bicarbonate. Within 1826 studies totalling 34,889 participants, just 23% of participants were women, although 34% of studies included at least one woman. Across different supplements, 0–8% of studies investigated women exclusively, while fewer (0–2%) were specifically designed to compare sex-based responses. The annual publication of female-specific studies was ~8 times fewer than those investigating exclusively male cohorts. Interestingly, 15% of the female participants were classified as international/world-class athletes, compared with 7% of men. Most studies investigated performance outcomes but displayed poorer representation of women (16% of participants), whereas health-focussed studies had the greatest proportion of female participants (35%). Only 14% of studies including women attempted to define menstrual status, with only three studies (~0.5%) implementing best practice methodologies to assess menstrual status. New research should target the efficacy of performance supplements in female athletes, and future sports nutrition recommendations should specifically consider how well female athletes have contributed to the evidence-base.
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Poole DC, Ferguson SK, Musch TI, Porcelli S. Role of nitric oxide in convective and diffusive skeletal microvascular oxygen kinetics. Nitric Oxide 2022; 121:34-44. [PMID: 35123062 DOI: 10.1016/j.niox.2022.01.005] [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: 09/13/2021] [Revised: 12/29/2021] [Accepted: 01/27/2022] [Indexed: 10/19/2022]
Abstract
Progress in understanding physiological mechanisms often consists of discrete discoveries made across different models and species. Accordingly, understanding the mechanistic bases for how altering nitric oxide (NO) bioavailability impacts exercise tolerance (or not) depends on integrating information from cellular energetics and contractile regulation through microvascular/vascular control of O2 transport and pulmonary gas exchange. This review adopts state-of-the-art concepts including the intramyocyte power grid, the Wagner conflation of perfusive and diffusive O2 conductances, and the Critical Power/Critical Speed model of exercise tolerance to address how altered NO bioavailability may, or may not, affect physical performance. This question is germane from the elite athlete to the recreational exerciser and particularly the burgeoning heart failure (and other clinical) populations for whom elevating O2 transport and/or exercise capacity translates directly to improved life quality and reduced morbidity and mortality. The dearth of studies in females is also highlighted, and areas of uncertainty and questions for future research are identified.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Scott K Ferguson
- Department of Kinesiology and Exercise Science, University of Hawaii, Hilo, HI, 96720, USA
| | - Timothy I Musch
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Simone Porcelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.
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Escribano-Ott I, Calleja-González J, Mielgo-Ayuso J. Ergo-Nutritional Intervention in Basketball: A Systematic Review. Nutrients 2022; 14:638. [PMID: 35276997 PMCID: PMC8839588 DOI: 10.3390/nu14030638] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 11/16/2022] Open
Abstract
Using nutritional supplements is a widespread strategy among basketball players to ensure the appropriate provision of energy and nutrients to avoid certain complaints. Particularly in basketball, there is no consensus on the type, quantity or form of use in which these supplements should be administered. Therefore, the main aim of this systematic review is to highlight the ergo-nutritional aids that may be effective in basketball. A structured search was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA®) guidelines in the Medline/PubMed and Web of Science, Cochrane Library, and Scopus databases until 31 December 2021; no year restriction was applied to the search strategy. There were no filters applied to the basketball players' level, gender, race, or age to increase the power of the analysis. The results of this systematic review have shown that the effective dose of caffeine to enhance anaerobic performance and the feeling of vigorousness and energy ranges from 3 to 6 mg·kg-1, showing more positive effects when is supplemented 60-75 min before exercise in the morning and in test-based task. On the other hand, vitamin E (ranging from 200 to 268 mg), vitamin D (10,000 IU) and EPA (2 g) may have a potential role in recovery and wellness. The primary limitation of this study is the scarcity of studies related to nutritional supplementation in basketball players. However, a major strength is that this is the first systematic review describing what ergo-nutritional aids may be specifically helpful for basketball. Despite the need for future studies, certain nutritional supplements may have promising advantages for basketball (long-term supplementation of nitrates for recovery), whereas others (β-alanine, sodium bicarbonate, and acute nitrate supplementation) might theoretically be regarded as not interesting for basketball, or even not recommended by the World Anti-Doping Agency (WADA) as bovine colostrum.
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Affiliation(s)
- Ignacio Escribano-Ott
- Department of Physical Education and Sport, Faculty of Education and Sport, University of the Basque Country, 01007 Vitoria, Spain;
| | - Julio Calleja-González
- Department of Physical Education and Sport, Faculty of Education and Sport, University of the Basque Country, 01007 Vitoria, Spain;
| | - Juan Mielgo-Ayuso
- Department of Health Sciences, Faculty of Health Sciences, University of Burgos, 09001 Burgos, Spain;
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Tan R, Cano L, Lago-Rodríguez Á, Domínguez R. The Effects of Dietary Nitrate Supplementation on Explosive Exercise Performance: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19020762. [PMID: 35055584 PMCID: PMC8775572 DOI: 10.3390/ijerph19020762] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/07/2023]
Abstract
Dietary nitrate supplementation is evidenced to induce physiological effects on skeletal muscle function in fast-twitch muscle fibers and may enhance high-intensity exercise performance. An important component of sport-specific skills is the ability to perform explosive movements; however, it is unclear if nitrate supplementation can impact explosive efforts. We examined the existing evidence to determine whether nitrate supplementation improves explosive efforts lasting ≤ 6 s. PubMed, Scopus and Directory of Open Access Journals (DOAJ) were searched for articles using the following search strategy: (nitrate OR nitrite OR beetroot) AND (supplement OR supplementation) AND (explosive OR power OR high intensity OR high-intensity OR sprint* OR “athletic performance”). Out of 810 studies, 18 were eligible according to inclusion criteria. Results showed that 4 of the 10 sprint-type studies observed improved sprint time, power output, and total work in cycling or running, whereas 4 of the 10 resistance-based exercise studies observed improvements to power and velocity of free-weight bench press as well as isokinetic knee extension and flexion at certain angular velocities. These results suggest that nitrate potentially improves explosive exercise performance, but further work is required to clarify the factors influencing the efficacy of nitrate in different exercise modalities.
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Affiliation(s)
- Rachel Tan
- Faculty of Sports Medicine, Natural Sciences Division, Pepperdine University, Malibu, CA 90263, USA;
| | - Leire Cano
- Independent Researcher, 48991 Getxo, Spain;
| | - Ángel Lago-Rodríguez
- Movement, Brain and Health Group, Center of Higher Education Alberta Giménez, 07013 Palma de Mallorca, Spain
- Correspondence: ; Tel.: +34-680-330-105
| | - Raúl Domínguez
- Departamento de Motricidad Humana y Rendimiento, Universidad de Sevilla, 41013 Sevilla, Spain;
- Studies Research Group in Neuromuscular Responses (GEPREN), University of Lavras, Lavras 37200-000, Brazil
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Burgos J, Viribay A, Fernández-Lázaro D, Calleja-González J, González-Santos J, Mielgo-Ayuso J. Combined Effects of Citrulline Plus Nitrate-Rich Beetroot Extract Co-Supplementation on Maximal and Endurance-Strength and Aerobic Power in Trained Male Triathletes: A Randomized Double-Blind, Placebo-Controlled Trial. Nutrients 2021; 14:40. [PMID: 35010917 PMCID: PMC8746866 DOI: 10.3390/nu14010040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 11/24/2022] Open
Abstract
Citrulline (CIT) and nitrate-rich beetroot extract (BR) are ergogenic aids and nitric oxide (NO) precursors. In addition, both supplements seem to have other actions at the level of muscle metabolism that can benefit strength and aerobic power performance. Both supplements have been studied in numerous investigations in isolation. However, scientific evidence combining both supplements is scarce, and to the best of the authors' knowledge, there is no current study of endurance athletes. Therefore, the main purpose of this study was to determine the effect of 9 weeks of CIT plus BR supplementation on maximal and endurance-strength performance and aerobic power in male triathletes. This study was a randomized double-blind, placebo-controlled trial where participants (n = 32) were randomized into four different groups: placebo group (PLG; n = 8), CIT plus BR group (CIT- BRG; 3 g/kg/day of CIT plus 3 mg/kg/day of nitrates (NO3-); n = 8), CIT group (CITG; 3 g/kg/day; n = 8) and BR group (BRG; 3 mg/kg/day of NO3-; n = 8). Before (T1) and after 9 weeks (T2), four physical condition tests were carried out in order to assess sport performance: the horizontal jump test (HJUMP), handgrip dynamometer test, 1-min abdominal tests (1-MAT) and finally, the Cooper test. Although, no significant interactions (time × supplementation groups) were found for the strength tests (p > 0.05), the CIT- BRG supplementation presented a trend on HJUMP and 1-MAT tests confirmed by significant increase between two study moments in CIT-BRG. Likewise, CIT-BRG presented significant interactions in the aerobic power test confirmed by this group's improve estimated VO2max during the study with respect to the other study groups (p = 0.002; η2p = 0.418). In summary, supplementing with 3 g/day of CIT and 2.1 g/day of BR (300 mg/day of NO3-) for 9 weeks could increase maximal and endurance strength. Furthermore, when compared to CIT or BR supplementation alone, this combination improved performance in tests related to aerobic power.
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Affiliation(s)
- José Burgos
- Department of Nursing and Physiotherapy, University of León, 24071 León, Spain
- Burgos Nutrition, Physiology, Nutrition and Sport, 26007 Logroño, Spain;
| | - Aitor Viribay
- Glut4Science, Physiology, Nutrition and Sport, 01004 Vitoria-Gasteiz, Spain;
| | - Diego Fernández-Lázaro
- Department of Cellular Biology, Histology and Pharmacology, Faculty of Health Sciences, University of Valladolid, Campus of Soria, 42003 Soria, Spain;
- Neurobiology Research Group, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain
| | - Julio Calleja-González
- Department of Physical Education and Sport, Faculty of Education and Sport, University of the Basque Country, 01007 Vitoria, Spain;
| | - Josefa González-Santos
- Department of Health Sciences, Faculty of Health Sciences, University of Burgos, 09001 Burgos, Spain;
| | - Juan Mielgo-Ayuso
- Department of Health Sciences, Faculty of Health Sciences, University of Burgos, 09001 Burgos, Spain;
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Burke LM, Hall R, Heikura IA, Ross ML, Tee N, Kent GL, Whitfield J, Forbes SF, Sharma AP, Jones AM, Peeling P, Blackwell JR, Mujika I, Mackay K, Kozior M, Vallance B, McKay AKA. Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers. Nutrients 2021; 13:nu13082767. [PMID: 34444928 PMCID: PMC8398364 DOI: 10.3390/nu13082767] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/03/2021] [Accepted: 08/07/2021] [Indexed: 11/16/2022] Open
Abstract
Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes’ economy as well as the performance effects in elite groups.
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Affiliation(s)
- Louise M. Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- Correspondence: ; Tel.: +61-422-635-869
| | - Rebecca Hall
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Ida A. Heikura
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Megan L. Ross
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Nicolin Tee
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Georgina L. Kent
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
| | - Sara F. Forbes
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- UniSA Online, University of South Australia, Adelaide, SA 5000, Australia
| | - Avish P. Sharma
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- Triathlon Australia, Burleigh Heads, Gold Coast, QLD 4220, Australia
| | - Andrew M. Jones
- Sport and Health Sciences, University of Exeter, Heavitree Road, Exeter EX1 2LU, UK; (A.M.J.); (J.R.B.)
| | - Peter Peeling
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA 6009, Australia;
- West Australian Institute of Sport, Mt Claremont, Nedlands, WA 6010, Australia
| | - Jamie R. Blackwell
- Sport and Health Sciences, University of Exeter, Heavitree Road, Exeter EX1 2LU, UK; (A.M.J.); (J.R.B.)
| | - Iñigo Mujika
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country, 48940 Leioa, Basque Country, Spain;
- Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago 7501015, Chile;
| | - Karen Mackay
- Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago 7501015, Chile;
- School of Exercise & Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Marta Kozior
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
| | - Brent Vallance
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Athletics Australia, South Melbourne, Melbourne, VIC 3205, Australia
| | - Alannah K. A. McKay
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA 6009, Australia;
- West Australian Institute of Sport, Mt Claremont, Nedlands, WA 6010, Australia
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