Search Results

You are looking at 31 - 40 of 59 items for

  • Author: David Pyne x
Clear All Modify Search
Restricted access

Paul G. Montgomery, David B. Pyne and Clare L. Minahan

Purpose:

To characterize the physical and physiological responses during different basketball practice drills and games.

Methods:

Male basketball players (n = 11; 19.1 ± 2.1 y, 1.91 ± 0.09 m, 87.9 ± 15.1 kg; mean ± SD) completed offensive and defensive practice drills, half court 5on5 scrimmage play, and competitive games. Heart rate, VO2 and triaxial accelerometer data (physical demand) were normalized for individual participation time. Data were log-transformed and differences between drills and games standardized for interpretation of magnitudes and reported with the effect size (ES) statistic.

Results:

There was no substantial difference in the physical or physiological variables between offensive and defensive drills; physical load (9.5%; 90% confidence limits ±45); mean heart rate (-2.4%; ±4.2); peak heart rate (-0.9%; ±3.4); and VO2 (–5.7%; ±9.1). Physical load was moderately greater in game play compared with a 5on5 scrimmage (85.2%; ±40.5); with a higher mean heart rate (12.4%; ±5.4). The oxygen demand for live play was substantially larger than 5on5 (30.6%; ±15.6).

Conclusions:

Defensive and offensive drills during basketball practice have similar physiological responses and physical demand. Live play is substantially more demanding than a 5on5 scrimmage in both physical and physiological attributes. Accelerometers and predicted oxygen cost from heart rate monitoring systems are useful for differentiating the practice and competition demands of basketball.

Restricted access

Andrew A. Dingley, David B. Pyne and Brendan Burkett

Disabilities in Paralympic swimming could impact a swimmer’s ability to execute an effective swim-start. We examined how swim-start performance differed between severity and type of physical disability. Swim-starts were measured in 55 elite Paralympic swimmers from eight different Paralympic classes; S14, S13, S10-S6, S3 grouped as no- (classes S13 & S14), low- (S9 & S10), mid- (S7 & S8) or high- (≤ S6) severity of physical disability and also by type of physical disability (upper, lower, and palsy) to provide meaningful comparisons. The swimmer’s competitive level was determined by the international point score (IPS). Swimmers with no physical disability were significantly faster in most swim-start phases compared with those with physical disabilities, as were swimmers with low-severity disabilities compared with the mid- and high-severity groups. Block velocity was highly negatively correlated (r = –0.57 to –0.86) with 15-m swimming time for all groups except high-severity disabilities. Free-swim velocity is a priority area for improving swim-starts for swimmers regardless of disability, given large correlations between this measure and IPS. Swimmers with lower body or high-severity disabilities spent a smaller percentage of time overall in the underwater phase. Assessment of four specific phases of the swim-start highlight distinctive priorities for coaches working with Paralympic swimmers in an applied biomechanical manner.

Restricted access

David B. Pyne, Joshua H. Guy and Andrew M. Edwards

Heat and immune stress can affect athletes in a wide range of sports and environmental conditions. The classical thermoregulatory model of heat stress has been well characterized, as has a wide range of practical strategies largely centered on cooling and heat-acclimation training. In the last decade evidence has emerged of an inflammatory pathway that can also contribute to heat stress. Studies are now addressing the complex and dynamic interplay between hyperthermia, the coagulation cascade, and a systemic inflammatory response occurring after transient damage to the gastrointestinal tract. Damage to the intestinal mucosal membrane increases permeability, resulting in leakage of endotoxins into the circulation. Practical strategies that target both thermoregulatory and inflammatory causes of heat stress include precooling; short-term heat-acclimation training; nutritional countermeasures including hydration, energy replacement, and probiotic supplementation; pacing strategies during events; and postevent cooling measures. Cooperation between international, national, and local sporting organizations is required to ensure that heat-management policies and strategies are implemented effectively to promote athletes’ well-being and performance.

Restricted access

Iñigo Mujika, Rafa González De Txabarri and David Pyne

Energicer is a new solution which purportedly increases evaporative cooling during exercise in the heat.

Purpose:

To evaluate the effect of Energicer on performance during indoor rowing in a warm environment.

Methods:

Eighteen highly trained rowers (age 23.3 ± 6.7 y, height 181.3 ± 6.0 cm, mass 76.7 ± 5.0 kg, peak aerobic power (PAP) 322.1 ± 24.3 W; mean ± SD) performed two indoor rowing trials at 25.0°C and 65.0% relative humidity. Each trial consisted of 10 min at 55% PAP, 5 min of rest, 10 min at 70% PAP, 10 min of rest, and 2000 m time trial. Subjects were randomly assigned to an experimental (COOL) or a placebo (PLA) condition, using a double-blind, crossover design. During COOL, subjects wore sweatbands soaked in Energicer on both forearms; during PLA, they wore identical sweatbands soaked in cool water. Physiological measures and rowing performance were analyzed in a post-test-only crossover design. Magnitude of the difference between treatments was interpreted using the Cohen’s effect statistic.

Results:

No substantial differences were observed in heart rate, blood lactate and RPE between treatments during the submaximal row (COOL 163 ± 10 bpm, 4.3 ± 1.0 mM, 14.5 ± 1.8; PLA 165 ± 11 bpm, 4.8 ± 1.4 mM, 14.6 ± 1.6) and the time trial (COOL 179 ± 9 bpm, 10.7 ± 2.3 mM, 20 ± 0; PLA 179 ± 10 bpm, 11.1 ± 2.2 mM, 20 ± 0). Time (419 ± 11 vs 420 ± 12 s), mean power (305 ± 24 vs 304 ± 26 W), sweat loss (1013 ± 186 vs 981 ± 161 mL) and pacing strategy during the time trial were similar in COOL and PLA. The magnitude of differences between treatments was trivial for all measured variables.

Conclusion:

Energicer failed to provide a substantial benefit during indoor rowing in a warm environment. Whether Energicer is beneficial during more prolonged exercise and/or under more stressful environmental conditions remains to be elucidated.

Restricted access

David B. Pyne, Megan E. Anderson and Will G. Hopkins

Purpose:

To characterize within-subject changes in anthropometric characteristics of elite swimmers within and between seasons.

Methods:

The subjects were 77 elite swimmers (31 females, 46 males, age 15 to 30 years) monitored over 0.4 to 9.2 years. One anthropometrist recorded their body mass (M) and sum of 7 skin-fold thicknesses (S) on 2042 occasions over 14 years from phase to phase within a season and over consecutive seasons. We estimated change in lean mass using a newly derived index (LMI) that tracked changes in M controlled for changes in S.

Results:

The LMI is M/Sx, where x = 0.16 ± 0.04 for females and 0.15 ± 0.05 for males (mean ± SD). The LMI of males increased 1.1% (95% confidence limits ± 0.2%) between preseason and taper phases, almost twice as much as that of females (0.6% ± 0.3%). During the same period, M and S fell by ~1% and ~11%, respectively. From season to season LMI increased by 0.9% (0.8% to 1.0%) for males and 0.5% (0.3% to 0.7%) for females. All these within-subject effects on LMI were well defined (±~0.3%). The typical variation (SD) of an individual’s LMI was 1.2% for assessments within a season and 1.9% between seasons, with a short-term technical error of measurement of ~0.5%.

Conclusion:

Coaches and conditioners should typically expect a twofold greater increase in lean mass in male swimmers within and between seasons than in females. An LMI of the form M/Sx should be useful for monitoring individual swimmers and athletes in other sports in which body composition affects performance.

Restricted access

Andrew A. Dingley, David B. Pyne and Brendan Burkett

Purpose:

To characterize relationships between propulsion, anthropometry, and performance in Paralympic swimming.

Methods:

A cross-sectional study of swimmers (13 male, 15 female) age 20.5 ± 4.4 y was conducted. Subject locomotor categorizations were no physical disability (n = 8, classes S13–S14) and low-severity (n = 11, classes S9–S10) or midseverity disability (n = 9, classes S6–S8). Full anthropometric profiles estimated muscle mass and body fat, a bilateral swim-bench ergometer quantified upper-body power production, and 100-m time trials quantified swimming performance.

Results:

Correlations between ergometer mean power and swimming performance increased with degree of physical disability (low-severity male r = .65, ±0.56, and female r = .68, ±0.64; midseverity, r = .87, ±0.41, and r = .79, ±0.75). The female midseverity group showed nearperfect (positive) relationships for taller swimmers’ (with a greater muscle mass and longer arm span) swimming faster, while for female no- and low-severity-disability groups, greater muscle mass was associated with slower velocity (r = .78, ±0.43, and r = .65, ±0.66). This was supported with lighter females (with less frontal surface area) in the low-severity group being faster (r = .94, ±0.24). In a gender contrast, low-severity males with less muscle mass (r = -.64, ±0.56), high skinfolds (r = .78, ±0.43), a longer arm span (r = .58, ±0.60) or smaller frontal surface area (r = -.93, ±0.19) were detrimental to swimming-velocity production.

Conclusion:

Low-severity male and midseverity female Paralympic swimmers should be encouraged to develop muscle mass and upper-body power to enhance swimming performance. The generalized anthropometric measures appear to be a secondary consideration for coaches.

Restricted access

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.

Restricted access

Anthea C. Clarke, Judith M. Anson and David B. Pyne

Purpose:

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.

Methods:

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).

Results:

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.

Conclusion:

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.

Restricted access

Philippe Hellard, Robin Pla, Ferran A. Rodríguez, David Simbana and David B. Pyne

Purpose: To compare the dynamics of maximal oxygen uptake (V˙O2), blood lactate ([La]b), total energy expenditure (E tot), and contributions of the aerobic (E aer), alactic anaerobic (E an,al), and lactic anaerobic (E an,lac) metabolic energy pathways over 4 consecutive 25-m laps (L0–25, L25–50, etc) of a 100-m maximal freestyle swim. Methods: Elite swimmers comprising 26 juniors (age = 16 [1] y) and 23 seniors (age = 24 [5] y) performed 100 m at maximal speed and then 3 trials (25, 50, and 75 m) at the same pace as that of the 100 m. [La]b was collected, and V˙O2 was measured 20 s postexercise. Results: The estimated energetic contributions for the 100-m trial are presented as mean (SD): E aer, 51% (8%); E an,al, 18% (2%); E an,lac, 31% (9%). V˙O2 increased from L0–25 to L25–50 (mean = 3.5 L·min−1; 90% confidence interval [CI], 3.4–3.7 L·min−1 to mean = 4.2 L·min−1; 90% CI, 4.0–4.3 L·min−1) and then stabilized in the 2nd 50 m (mean = 4.1 L·min−1; 90% CI, 3.9–4.3 L·min−1 to mean = 4.2 L·min−1; 90% CI, 4.0–4.4 L·min−1). E tot (juniors, 138 [18] kJ; seniors, 168 [26] kJ), E an,al (juniors, 27 [3] kJ; seniors, 30 [3] kJ), and E an,lac (juniors, 38 [12] kJ; seniors, 62 [24] kJ) were 11–58% higher in seniors. Faster swimmers (n = 26) had higher V˙O2(4.6L·min1, 90% CI 4.4–4.8 L·min−1 vs 3.9 L·min−1, 90% CI 3.6–4.2 L·min−1), and E aer power was associated with fast performances (P < .001). Conclusion: Faster swimmers were characterized by higher V˙O2 and less time to reach the highest V˙O2 at ∼50 m of the 100-m swim. Anaerobic qualities become more important with age.

Restricted access

Philo U. Saunders, Richard D. Telford, David B. Pyne, Christopher J. Gore and Allan G. Hahn

We quantified the effect of an extended live high-train low (LHTL) simulated altitude exposure followed by a series of training camps at natural moderate altitude on competitive performance in seven elite middle-distance runners (Vo2max 71.4 ± 3.4 mL·min−1·kg−1, mean ± SD). Runners spent 44 ± 7 nights (mean ± SD) at a simulated altitude of 2846 ± 32 m, and a further 4 X 7- to 10-d training at natural moderate altitude (1700–2200 m) before racing. The combination of simulated LHTL and natural altitude training improved competitive performance by 1.9% (90% confidence limits, 1.3-2.5%). Middle-distance runners can confidently use a combination of simulated and natural altitude to stimulate adaptations responsible for improving performance.