David B. Pyne
David B. Pyne
Louise M. Burke and David B. Pyne
Bicarbonate loading is a popular ergogenic aid used primarily by athletes in short-duration, high-intensity sporting events and competitions. Controlled experimental trials have shown that small (worthwhile) benefits can obtained from acute doses of bicarbonate taken before exercise. Gastrointestinal problems encountered by some athletes limit the widespread use of this practice, however. The transfer of positive research findings to the competitive environment has proved problematic for some individuals. More recent applications involve serial ingestion of bicarbonate over several days before competition or during high-intensity training sessions over a few weeks. A number of research questions need to be addressed to enhance applications of bicarbonate loading in the elite sport environment. This commentary examines some of research and practical issues of bicarbonate loading used to enhance both training and competitive performance.
David B. Pyne and Rick L. Sharp
The aquatic sports competitions held during the summer Olympic Games include diving, open-water swimming, pool swimming, synchronized swimming, and water polo. Elite-level performance in each of these sports requires rigorous training and practice to develop the appropriate physiological, biomechanical, artistic, and strategic capabilities specific to each sport. Consequently, the daily training plans of these athletes are quite varied both between and within the sports. Common to all aquatic athletes, however, is that daily training and preparation consumes several hours and involves frequent periods of high-intensity exertion. Nutritional support for this high-level training is a critical element of the preparation of these athletes to ensure the energy and nutrient demands of the training and competition are met. In this article, we introduce the fundamental physical requirements of these sports and specifically explore the energetics of human locomotion in water. Subsequent articles in this issue explore the specific nutritional requirements of each aquatic sport. We hope that such exploration will provide a foundation for future investigation of the roles of optimal nutrition in optimizing performance in the aquatic sports.
David B. Pyne, Matt Spencer, and Iñigo Mujika
One of the challenges for sports scientists working in football is to balance the needs for routine fitness testing with daily fatigue and well-being monitoring to best manage the physical preparation of players. In this commentary, the authors examine contemporary issues of fitness testing in football to identify ways of improving the value of routine testing and monitoring. A testing program must be well planned and organized to ensure that the results are useful. Different tests can be employed for younger and older players. A rigorous approach to analysis and interpretation of results is desirable, and database management must address both short- and long-term requirements of players, staff, and programs.
David Simbaña Escobar, Philippe Hellard, David B. Pyne, and Ludovic Seifert
To study the variability in stroking parameters between and within laps and individuals during competitions, we compared and modeled the changes of speed, stroke rate, and stroke length in 32 top-level male and female swimmers over 4 laps (L1–L4) in 200-m freestyle events using video-derived 2-dimensional direct linear transformation. For the whole group, speed was greater in L1, with significant decreases across L2, L3, and L4 (1.80 ± 0.10 vs 1.73 ± 0.08; 1.69 ± 0.09; 1.66 ± 0.09 · s−1, P < .05). This variability was attributed to a decrease in stroke length (L2: 2.43 ± 0.19 vs L4: 2.20 ± 0.13 m, P < .05) and an increase in stroke rate (L2: 42.8 ± 2.6 vs L4: 45.4 ± 2.3 stroke · min−1, P < .05). The coefficient of variation and the biological coefficient of variation in speed were greater for male versus female (3.9 ± 0.7 vs 3.1 ± 0.7; 2.9 ± 1.0 vs 2.6 ± 0.7, P < .05) and higher in L1 versus L2 (3.9 ± 1.3 vs 3.1 ± 0.1; 2.9 ± 0.9 vs 2.3 ± 0.7, P < .05). Intra-lap speed values were best represented by a cubic (n = 38), then linear (n = 37) and quadratic model (n = 8). The cubic fit was more frequent for males (43.8%) than females (15.6%), suggesting greater capacity to generate higher acceleration after the turn. The various stroking parameters managements within lap suggest that each swimmer adapts his/her behavior to the race constraints.
Israel Halperin, David B. Pyne, and David T. Martin
Internal validity refers to the degree of control exerted over potential confounding variables to reduce alternative explanations for the effects of various treatments. In exercise and sports-science research and routine testing, internal validity is commonly achieved by controlling variables such as exercise and warm-up protocols, prior training, nutritional intake before testing, ambient temperature, time of testing, hours of sleep, age, and gender. However, a number of other potential confounding variables often do not receive adequate attention in sports physiology and performance research. These confounding variables include instructions on how to perform the test, volume and frequency of verbal encouragement, knowledge of exercise endpoint, number and gender of observers in the room, influence of music played before and during testing, and the effects of mental fatigue on performance. In this review the authors discuss these variables in relation to common testing environments in exercise and sports science and present some recommendations with the goal of reducing possible threats to internal validity.
Iñigo Mujika, Luis Villanueva, Marijke Welvaert, and David B. Pyne
Context/Background: International-level swimmers periodize their training to qualify for major championships, then improve further at these events. However, the effects of various factors that could affect performance progressions have not been described systematically. Purpose: To quantify the pattern of change in performance between season best qualifying time and the major championships of the year and to assess the influence of time between performance peaks, ranking at the major events, stroke, event distance, sex, age, and country. Methods: A total of 7832 official competition times recorded at 4 FINA World Championships and 2 Olympic Games between 2011 and 2017 were compared with each swimmer’s season best time prior to the major event of the year. Percentage change in performance was related with the time elapsed between season best and major competition, race event, sex, age, and country using linear mixed modeling. Results: Faster performance (−0.79% [0.67%]; mean [SD]) at the major competition of the year occurred in 38% of all observations vs 62% no change or regression (1.10% [0.88%]). The timing between performance peaks (<34 to >130 d) had little effect on performance progressions (P = .83). Only medal winners (−0.87% [0.91%]), finalists (−0.16% [0.97%]), and US swimmers (−0.44% [1.08%]) progressed between competitions. Stroke, event distance, sex, and age had trivial impact on performance progression. Conclusions: Performance progressions at Olympic Games and World Championships were not determined by timing between performance peaks. Performance progression at a major competition appears necessary to win a medal or make the final, independent of race event, sex, and age.
Anthea C. Clarke, Judith M. Anson, and David B. Pyne
To examine relationships between on-field game movement patterns and changes in markers of neuromuscular fatigue and muscle damage during a 2-d women’s rugby sevens tournament.
Female national (mean ± SD n = 12, 22.3 ± 2.5 y, 1.67 ± 0.04 m, 65.8 ± 4.6 kg) and state (n = 10, 24.4 ± 4.3 y, 1.67 ± 0.03 m, 66.1 ± 7.9 kg) representative players completed baseline testing for lower-body neuromuscular function (countermovement-jump [CMJ] test), muscle damage (capillary creatine kinase [CK]), perceived soreness, and perceived recovery. Testing was repeated after games on days 1 and 2 of the tournament. GPS (5-Hz) data were collected throughout the tournament (4−6 games/player).
National players were involved in greater on-field movements for total time, distance, high-speed running (>5 m/s), and impacts >10 g (effect size [ES] = 0.55−0.97) and displayed a smaller decrement in performance from day 1 to day 2. Despite this, state players had a much greater 4-fold increase (ΔCK = 737 U/L) in CK compared with the 2-fold increase (ΔCK = 502 U/L) in national players (ES = 0.73). Both groups had similar perceived soreness and recovery while CMJ performance was unchanged. High-speed running and impacts >10 g were largely correlated (r = .66−.91) with ΔCK for both groups.
A 2-day women’s rugby sevens tournament elicits substantial muscle damage; however, there was little change in lower-body neuromuscular function. Modest increases in CK can largely be attributed to high-speed running and impacts >10 g that players typically endure.