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1.
Effect of Waters Enriched in O2 by Injection or Electrolysis on Performance and the Cardiopulmonary and Acid-Base Response to High Intensity Exercise.
Daussin, FN, Péronnet, F, Charton, A, Lonsdorfer, E, Doutreleau, S, Geny, B, Richard, R
Nutrients. 2021;(12)
Abstract
Several brands of water enriched with O2 (O2-waters) are commercially available and are advertised as wellness and fitness waters with claims of physiological and psychological benefits, including improvement in exercise performance. However, these claims are based, at best, on anecdotal evidence or on a limited number of unreliable studies. The purpose of this double-blind randomized study was to compare the effect of two O2-waters (~110 mg O2·L-1) and a placebo (10 mg O2·L-1, i.e., close to the value at sea level, 9-12 mg O2·L-1) on the cardiopulmonary responses and on performance during high-intensity exercise. One of the two O2-waters and the placebo were prepared by injection of O2. The other O2-water was enriched by an electrolytic process. Twenty male subjects were randomly allocated to drink one of the three waters in a crossover study (2 L·day-1 × 2 days and 15 mL·kg-1 90 min before exercise). During each exercise trial, the subjects exercised at 95.9 ± 4.7% of maximal workload to volitional fatigue. Exercise time to exhaustion and the cardiopulmonary responses, arterial lactate concentration and pH were measured. Oxidative damage to proteins, lipids and DNA in blood was assessed at rest before exercise. Time to exhaustion (one-way ANOVA) and the responses to exercise (two-way ANOVA [Time; Waters] with repeated measurements) were not significantly different among the three waters. There was only a trend (p = 0.060) for a reduction in the time constant of the rapid component of VO2 kinetics with the water enriched in O2 by electrolysis. No difference in oxidative damage in blood was observed between the three waters. These results suggest that O2-water does not speed up cardiopulmonary response to exercise, does not increase performance and does not trigger oxidative stress measured at rest.
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2.
A Mixed-Method Approach of Pre-Cooling Enhances High-Intensity Running Performance in the Heat.
Xu, M, Wu, Z, Dong, Y, Qu, C, Xu, Y, Qin, F, Wang, Z, Nassis, GP, Zhao, J
Journal of sports science & medicine. 2021;(1):26-34
Abstract
We investigated whether single or combined methods of pre-cooling could affect high-intensity exercise performance in a hot environment. Seven male athletes were subjected to four experimental conditions for 30 min in a randomised order. The four experimental conditions were: 1) wearing a vest cooled to a temperature of 4 ℃ (Vest), 2) consuming a beverage cooled to a temperature of 4 ℃ (Beverage), 3) simultaneous usage of vest and consumption of beverage (Mix), and 4) the control trial without pre-cooling (CON). Following those experimental conditions, they exercised at a speed of 80% VO2max until exhaustion in the heat (38.1 ± 0.6 ℃, 55.3 ± 0.3% RH). Heart rate (HR), rectal temperature (Tcore), skin temperature (Tskin), sweat loss (SL), urine specific gravity (USG), levels of sodium (Na+) and potassium (K+), rating of perceived exertion (RPE), thermal sensation (TS), and levels of blood lactic acid ([Bla]) were monitored. Performance was improved using the mixed pre-cooling strategy (648.43 ± 77.53 s, p = 0.016) compared to CON (509.14 ± 54.57 s). Tcore after pre-cooling was not different (Mix: 37.01 ± 0.27 ℃, Vest: 37.19 ± 0.33 ℃, Beverage: 37.03 ± 0.35 ℃) in all cooling conditions compared to those of CON (37.31 ±0.29 ℃). A similar Tcore values was achieved at exhaustion in all trials (from 38.10 ℃ to 39.00 ℃). No difference in the level of USG was observed between the conditions. Our findings suggest that pre-cooling with a combination of cold vest usage and cold fluid intake can improve performance in the heat.
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3.
Caffeine Supplementation or Carbohydrate Mouth Rinse Improves Performance.
Pereira, PEA, Azevedo, P, Azevedo, K, Azevedo, W, Machado, M
International journal of sports medicine. 2021;(2):147-152
Abstract
Training volume is one of the critical variables required to promote resistance training benefits (e. g., hypertrophy, muscular strength). Thus, strategies to improve training volume are required. We tested the hypothesis that there is an increase in performance and reduction in the rate of perceived exertion in strength training with caffeine supplementation, carbohydrate mouth rinse, and a synergistic effect of caffeine supplementation plus carbohydrate mouth rinse. We recruited 29 physically active women: 24±4 years, 60.0±7.9 kg, 161.0±6.0 cm. This study was a double-blind, randomized, placebo-controlled, and crossover one. The subjects performed all sessions of strength training under different conditions: caffeine (6.5 mg·kg-1 body mass); carbohydrate (6 g of maltodextrin rinsed for 10 s); caffeine plus carbohydrate; or placebo. We applied the ANOVA for repeated measures through the null-hypothesis statistical test, and the Bayes factors analyses approach. The subjects showed significant improvement in the total repetitions (P<0.01; BF10 ~99%) for both lower and upper limb exercises in all conditions compared to placebo without difference among interventions. The rate of perceived exertion (P>0.05) did not differ among interventions. However, BF10 analyses showed a higher probability of lower RPE for CAF intervention. We conclude that either caffeine supplementation or carbohydrate mouth rinse can improve performance in resistance training. There is no additional effect of caffeine plus carbohydrate.
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4.
Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis.
Lorenzo Calvo, J, Fei, X, Domínguez, R, Pareja-Galeano, H
Nutrients. 2021;(3)
Abstract
Cognitive functions are essential in any form of exercise. Recently, interest has mounted in addressing the relationship between caffeine intake and cognitive performance during sports practice. This review examines this relationship through a structured search of the databases Medline/PubMed and Web of Science for relevant articles published in English from August 1999 to March 2020. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PICOS model. The identified records reported on randomized cross-over studies in which caffeine intake (as drinks, capsules, energy bars, or gum) was compared to an identical placebo situation. There were no filters on participants' training level, gender, or age. For the systematic review, 13 studies examining the impacts of caffeine on objective measures of cognitive performance or self-reported cognitive performance were selected. Five of these studies were also subjected to meta-analysis. After pooling data in the meta-analysis, the significant impacts of caffeine only emerged on attention, accuracy, and speed. The results of the 13 studies, nevertheless, suggest that the intake of a low/moderate dose of caffeine before and/or during exercise can improve self-reported energy, mood, and cognitive functions, such as attention; it may also improve simple reaction time, choice reaction time, memory, or fatigue, however, this may depend on the research protocols.
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5.
ɑ-Lactalbumin Improves Sleep and Recovery after Simulated Evening Competition in Female Athletes.
Miles, KH, Clark, B, Fowler, PM, Gratwicke, MJ, Martin, K, Welvaert, M, Miller, J, Pumpa, KL
Medicine and science in sports and exercise. 2021;(12):2618-2627
Abstract
PURPOSE This study aimed to determine the efficacy of α-lactalbumin (A-LAC) supplementation for improving sleep and performance recovery after simulated evening competition in female athletes. METHODS Sixteen trained women (mean ± SD: age, 27 ± 7 yr; mass, 62 ± 10 kg; stature, 167 ± 8 cm) participated in this randomized double-blind three-arm crossover study. Participants completed a simulated evening competition before consuming either an A-LAC whey protein, whey protein placebo (PLA), or water control (CON) beverage. Sleep was monitored via polysomnography, and participants completed a series of physical, cognitive, and perceptual assessments before, and 14 and 24 h after simulated competition. RESULTS Non-rapid eye movement stage 2 sleep increased after competition in A-LAC (pre, 199 ± 44 min; post, 212 ± 37 min) but decreased in CON (pre, 228 ± 43 min; post, 195 ± 40 min) and PLA (pre, 224 ± 25 min; post, 211 ± 35 min; P = 0.012). In addition, Yo-Yo Intermittent Recovery Test Level 1 distance improved over time in A-LAC (baseline, 664 ± 332 m; 14 h post, 667 ± 326 m; 24 h post, 781 ± 427 m) compared with CON (baseline, 741 ± 366 m; 14 h post, 648 ± 351 m; 24 h post, 720 ± 407 m) and PLA (baseline, 763 ± 394 m; 14 h post, 636 ± 366 m; 24 h post, 720 ± 396 m; P < 0.001). CONCLUSIONS The findings indicate that A-LAC supplementation may be useful for retaining some sleep characteristics after evening competition, leading to improved physical performance in female athletes.
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6.
Effects of Co-Ingestion of β-Hydroxy-β-Methylbutyrate and L-Arginine α-Ketoglutarate on Jump Performance in Young Track and Field Athletes.
Kaczka, P, Kubicka, K, Batra, A, Maciejczyk, M, Kopera, E, Bira, J, Zając, T
Nutrients. 2021;(4)
Abstract
UNLABELLED The aim of the study was to determine the effect of simultaneous supplementation of β-hydroxy-β-methylbutyrate and L-Arginine α-ketoglutarate on lower limb power and muscle damage in medium distance runners aged 15.3 (±0.9) years old. METHODS The study group consisted of 40 volunteers aged 14-17 years practicing medium distance running for at least two years. The study lasted 12 days and followed a randomized, double-blind, placebo-controlled, parallel design. All subjects attended a familiarization session on day 0 before the test. The subjects were randomly divided into two groups: supplements and placebo group. The same training cycle protocol was used in both groups during the 12-day training period. Morning warm-up involved 10 min jogging at 60-75% of maximal heart rate and countermovement jump height measurement. Main training units were carried out for both groups with the same volume. Training load assessment (the daily session Rating of Perceived Exertion (s-RPE) method) method takes into consideration the intensity and the duration of the training session to calculate the "training load" (TL). RESULTS At the end of the training cycle, a significant (p = 0.002) decrease in the countermovement jump (CMJ) height was found in the placebo group when compared to the baseline. In the supplement group, there was no decrease in the countermovement jump height. Creatine kinase and lactate dehydrogenase concentration increased during the training days similarly in both groups and decreased on rest days. There were no differences between groups in enzymes concentration. The research results indicate that the supplement combination used in the supplements group prevented a reduction in the CMJ values. In contrast to the supplements group, in the placebo group, the CMJ changes were statistically significant: a noticeable (p = 0.002) decrease in CMJ was noted between the baseline measurement and the 6th measurement. The well-being of the subjects from both groups changed significantly during the training period, and the intergroup differences in the mood level were similar and not statistically significant. CONCLUSIONS The results of this study indicate that the daily co-supplementation with calcium salt of β-hydroxy-β-methylbutyrate (7.5 g) and L-Arginine α-ketoglutarate (10 g) during training might help to prevent decline in jump performance. No influence on muscle damage markers or mood was shown.
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7.
The Effect of Beetroot Ingestion on High-Intensity Interval Training: A Systematic Review and Meta-Analysis.
Wong, TH, Sim, A, Burns, SF
Nutrients. 2021;(11)
Abstract
Dietary nitrate supplementation has shown promising ergogenic effects on endurance exercise. However, at present there is no systematic analysis evaluating the effects of acute or chronic nitrate supplementation on performance measures during high-intensity interval training (HIIT) and sprint interval training (SIT). The main aim of this systematic review and meta-analysis was to evaluate the evidence for supplementation of dietary beetroot-a common source of nitrate-to improve peak and mean power output during HIIT and SIT. A systematic literature search was carried out following PRISMA guidelines and the PICOS framework within the following databases: PubMed, ProQuest, ScienceDirect, and SPORTDiscus. Search terms used were: ((nitrate OR nitrite OR beetroot) AND (HIIT or high intensity or sprint interval or SIT) AND (performance)). A total of 17 studies were included and reviewed independently. Seven studies applied an acute supplementation strategy and ten studies applied chronic supplementation. The standardised mean difference for mean power output showed an overall trivial, non-significant effect in favour of placebo (Hedges' g = -0.05, 95% CI -0.32 to 0.21, Z = 0.39, p = 0.69). The standardised mean difference for peak power output showed a trivial, non-significant effect in favour of the beetroot juice intervention (Hedges' g = 0.08, 95% CI -0.14 to 0.30, Z = 0.72, p = 0.47). The present meta-analysis showed trivial statistical heterogeneity in power output, but the variation in the exercise protocols, nitrate dosage, type of beetroot products, supplementation strategy, and duration among studies restricted a firm conclusion of the effect of beetroot supplementation on HIIT performance. Our findings suggest that beetroot supplementation offers no significant improvement to peak or mean power output during HIIT or SIT. Future research could further examine the ergogenic potential by optimising the beetroot supplementation strategy in terms of dosage, timing, and type of beetroot product. The potential combined effect of other ingredients in the beetroot products should not be undermined. Finally, a chronic supplementation protocol with a higher beetroot dosage (>12.9 mmol/day for 6 days) is recommended for future HIIT and SIT study.
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8.
Measures of impairment applicable to the classification of Paralympic athletes competing in wheelchair sports: A systematic review of validity, reliability and associations with performance.
Hutchinson, MJ, Phillips, JK, Mason, BS, Goosey-Tolfrey, VL, Beckman, EM
Journal of sports sciences. 2021;(sup1):40-61
Abstract
A fundamental aspect of classification systems in Paralympic sport is having valid and reliable measures of impairment. However, minimal consensus exists for assessing impaired strength, coordination and range of motion. This review aimed to systematically identify measures of upper body strength, coordination and range of motion impairments that meet the requirements for use in evidence-based classification systems in wheelchair sports. Three electronic databases were searched from 2003 until 31 August 2019 for studies that assessed upper body function of participants and used a measurement tool that assessed strength, coordination or range of motion. The body of evidence for each identified measure was appraised using the Grading of Recommendations Assessment, Development and Evaluation framework. Twenty-three studies were included: ten measured strength and coordination, and six measured range of motion. There was "moderate" confidence in using isometric strength for assessing strength impairment. Tapping tasks for the assessment of coordination impairment received a "low" confidence rating. All other identified measures of coordination and range of motion impairment received a "very low" confidence rating. Several potential measures were identified for assessing upper body strength, coordination and range of motion impairments. Further research is warranted to investigate their use for classification in Paralympic wheelchair sports.
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9.
Training Load, Heart Rate Variability, Direct Current Potential and Elite Long Jump Performance Prior and during the 2016 Olympic Games.
Coyne, J, Coutts, A, Newton, R, Haff, GG
Journal of sports science & medicine. 2021;(3):482-491
Abstract
The primary objective of this investigation was to investigate the relationships between training load (TL), heart rate variability (HRV) and direct current potential (DC) with elite long jump performance prior to and during the 2016 Olympics Games. Sessional ratings of perceived exertion (sRPE), training duration, HRV and DC were collected from four elite athletes (26.4 ± 1.4 years, height 1.83 ± 0.05 m, weight 68.9 ± 5.0 kg) for a 16-week period in qualification for and competition at the 2016 Olympic Games. Acute and chronic TL, training stress balance and differential load were calculated with three different smoothing methods. These TL measures along with HRV and DC were examined for their relationship to intra-athlete performance using repeated measure correlations and linear mixed models. Successful compared to unsuccessful intra-athlete performances were characterised by a higher chronic TL (p < 0.01, f2 = 0.31) but only when TL was exponentially smoothed. There were also negative correlations between HRV and performance (r = -0.55, p < 0.01) and HRV was significantly lower for more successful performances (p < 0.01, f2 = 0.19). Exponentially smoothed chronic TL was significantly higher and HRV was significantly lower for successful intra-athlete performances prior and during the 2016 Olympics Games in an elite group of long jump athletes. Monitoring sRPE and HRV measures and manipulating TL prior to competition seems worthwhile for elite long jump athletes.
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10.
Effects of Curcumin Supplementation on Inflammatory Markers, Muscle Damage, and Sports Performance during Acute Physical Exercise in Sedentary Individuals.
Dias, KA, da Conceição, AR, Oliveira, LA, Pereira, SMS, Paes, SDS, Monte, LF, Sarandy, MM, Novaes, RD, Gonçalves, RV, Della Lucia, CM
Oxidative medicine and cellular longevity. 2021;:9264639
Abstract
Exhaustive and acute unusual physical exercise leads to muscle damage. Curcumin has been widely studied due to the variety of its biological activities, attributed to its antioxidant and anti-inflammatory properties. Furthermore, it has shown positive effects on physical exercise practitioners. However, there is no literature consensus on the beneficial effects of curcumin in acute physical activities performed by sedentary individuals. Therefore, we systematically reviewed evidence from clinical trials on the main effects of curcumin supplementation on inflammatory markers, sports performance, and muscle damage during acute physical exercises in these individuals. We searched PubMed/MEDLINE, Scopus, Web of Science, and Embase databases, and only original studies were analyzed according to the PRISMA guidelines. The included studies were limited to supplementation of curcumin during acute exercise. A total of 5 studies were selected. Methodological quality assessments were examined using the SYRCLE's risk-of-bias tool. Most studies have shown positive effects of curcumin supplementation in sedentary individuals undergoing acute physical exercise. Overall, participants supplemented with curcumin showed less muscle damage, reduced inflammation, and better muscle performance. The studies showed heterogeneous data and exhibited methodological limitations; therefore, further research is necessary to ensure curcumin supplementation benefits during acute and high-intensity physical exercises. Additionally, mechanistic and highly controlled studies are required to improve the quality of the evidence and to elucidate other possible mechanisms. This study is registered with Prospero number CRD42021262718.