14 research outputs found
Acclimation training improves endurance cycling performance in the heat without inducing endotoxemia
No full textPurpose: While the intention of endurance athletes undertaking short term heat training protocols is to rapidly gain meaningful physical adaption prior to competition in the heat, it is currently unclear whether or not this process also presents an overt, acute challenge to the immune system. The aim of this study was therefore to examine the effects of heat training on both endurance performance and biomarkers associated with inflammatory and immune system responses.
Methods: Moderately-actively males (n = 24) were allocated randomly to either HOT (n = 8, 35°C, and 70% RH; NEUTRAL (n = 8, 20°C, and 45% RH); or a non-exercising control group, (CON, n = 8). Over the 18 day study HOT and NEUTRAL performed seven training sessions (40 min cycling at 55 of VO2 max) and all participants completed three heat stress tests (HST) at 35°C and 70% RH. The HST protocol comprised three × sub-maximal intervals followed by a 5 km time trial on a cycle ergometer. Serum samples were collected before and after each HST and analyzed for interleukin-6, immunoglobulin M and lipopolysaccharide.
Results: Both HOT and NEUTRAL groups experienced substantial improvement to 5 km time trial performance (HOT −33 ± 20 s, p = 0.02, NEUTRAL −39 ± 18 s, p = 0.01) but only HOT were faster (−45 ± 25 s, and −12 s ± 7 s, p = 0.01) in HST3 compared to baseline and HST2. Interleukin-6 was elevated after exercise for all groups however there were no significant changes for immunoglobulin M or lipopolysaccharide.
Conclusions: Short-term heat training enhances 5 km cycling time trial performance in moderately-fit subjects by ~6%, similar in magnitude to exercise training in neutral conditions. Three top-up training sessions yielded a further 3% improvement in performance for the HOT group. Furthermore, the heat training did not pose a substantial challenge to the immune system
Short-term reliability of inflammatory mediators and response to exercise in the heat
No full textProspective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test–retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28–38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation
Characterizing changes in fitness of basketball players within and between seasons
No full textCharacterizing changes in fitness of basketball players within and between season
Repetition Failure is a Key Determinant of Strength Development in Resistance Training
No full textRepetition Failure is a Key Determinant of Strength Development in Resistance Trainin
Power-related determinants of modified agility T-test performance in male adolescent basketball players
No full textScanlan, AT, Wen, N, Pyne, DB, Stojanović, E, Milanović, Z, Conte, D, Vaquera, A, and Dalbo, VJ. Power-related determinants of Modified Agility T-test performance in male adolescent basketball players. J Strength Cond Res XX(X): 000-000, 2019-Although the Modified Agility T-test (MAT) has been advocated for assessing change-of-direction performance in basketball, the power-related attributes emphasized during the test are unknown. Therefore, the aim of this study was to identify the power-related determinants of the MAT in basketball players. A cross-sectional, descriptive research design was used whereby national- and state-level male adolescent basketball players (n = 24; 17.3 ± 0.5 years) completed a battery of power-related performance tests. The tests administered included the MAT, isometric midthigh pull, 10-m sprint, countermovement jump, 1-step vertical jump, standing long jump, and repeated lateral bound. Associations between performance during the MAT and other tests were quantified, and performance in each test was compared between faster (>50th percentile) and slower (<50th percentile) players in the MAT. The MAT exhibited large correlations (p < 0.05) with standing long jump distance (r = -0.67, R = 45%), countermovement jump relative peak force (r = -0.63, R = 39%), isometric midthigh pull relative peak force (r = -0.55, R = 30%), and 10-m sprint time (r = 0.53, R = 28%). The faster group performed better (p < 0.05) during the standing long jump (mean difference; ±90% confidence limits: 0.16; ±0.12 m) and produced greater (p < 0.05) relative peak force during the isometric midthigh pull (2.5; ±2.3 N·kg) and countermovement jump (2.1; ±1.8 N·kg) than the slower group. The MAT complements other power-related tests used in basketball and stresses basketball-specific, power-related attributes in various movement planes. These data can inform training and testing approaches to optimize change-of-direction performance in basketball
Anthropometric and power-related attributes differ between competition levels in age-matched under-19-year-old male basketball players
No full textPurpose: To compare anthropometric and power-related attributes between competition levels in under-19-year-old (U19) male basketball players. Methods: National-level (n = 7; age: 17.7 [0.5] y), first-division state-level (n = 8; 17.4 [0.4] y), and seconddivision state-level (n = 8; 17.1 [0.4] y) players from Australian basketball programs participated in this pilot study. Players had various anthropometric attributes (height, standing reach height, wingspan, and body mass) and power-related attributes (isometric midthigh pull, linear sprint, countermovement jump, 1-step vertical jump, standing long jump, repeated lateral bound, and Modified Agility T Test) measured in the preseason. Differences between groups were assessed using 1-way analyses of variance with Tukey post hoc tests and effect sizes (ES) interpreted as trivial, <0.20; small, 0.20 to 0.59; moderate, 0.60 to 1.19; large, 1.20 to 1.99; and very large, ≥2.00. Results: Regarding anthropometric attributes, national-level players possessed greater (P < .05, large-very large) height (ES = 2.09), standing reach height (ES = 1.54), wingspan (ES = 1.45), and body mass (ES = 1.77) than second-division state-level players. For power-related attributes, national-level players possessed greater (P < .05, large-very large) isometric midthigh-pull peak force (ES = 1.46-2.57), sprint momentum (ES = 1.17-2.18), and countermovement jump peak force (ES = 1.73-2.01) than state-level players. Moreover, national-level players demonstrated greater (P < .05) 1-step vertical jump height (ES = 1.95, large) than second division state-level players. Conclusions: Specific anthropometric and power-related attributes clearly differ between competition levels in U19 male basketball players. This information can inform development of testing protocols, reference ranges, and training programs in practice. Further research is encouraged on this topic to confirm our findings across larger samples of basketball players
Short-term reliability of inflammatory mediators and response to exercise in the heat
No full textProspective application of serum cytokines, lipopolysaccharide, and heat shock proteins requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (seven day) reliability (at rest, n=12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60 min cycling, 34.5oC and 70% RH, n=20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and lipopolysaccharide (LPS). Test-retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-subject variation were IL-6 (19%, ± 20%; CV, ± 95% confidence limits) and LPS (23%, ± 13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28-38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ± 11%, p = <0.001) and although CRP had a modest CV (12%, ± 7%) it increased substantially post-exercise (p = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation
Anthropometric and Power-Related Attributes Differ Between Competition Levels in Age-Matched Under-19-Year-Old Male Basketball Players
No full textPURPOSE: To compare anthropometric and power-related attributes between competition levels in under-19-year-old (U19) male basketball players.METHODS: National-level (n = 7; age: 17.7 [0.5] y), first-division state-level (n = 8; 17.4 [0.4] y), and second-division state-level (n = 8; 17.1 [0.4] y) players from Australian basketball programs participated in this pilot study. Players had various anthropometric attributes (height, standing reach height, wingspan, and body mass) and power-related attributes (isometric midthigh pull, linear sprint, countermovement jump, 1-step vertical jump, standing long jump, repeated lateral bound, and Modified Agility T Test) measured in the preseason. Differences between groups were assessed using 1-way analyses of variance with Tukey post hoc tests and effect sizes (ES) interpreted as trivial, <0.20; small, 0.20 to 0.59; moderate, 0.60 to 1.19; large, 1.20 to 1.99; and very large, ≥2.00.RESULTS: Regarding anthropometric attributes, national-level players possessed greater (P < .05, large-very large) height (ES = 2.09), standing reach height (ES = 1.54), wingspan (ES = 1.45), and body mass (ES = 1.77) than second-division state-level players. For power-related attributes, national-level players possessed greater (P < .05, large-very large) isometric midthigh-pull peak force (ES = 1.46-2.57), sprint momentum (ES = 1.17-2.18), and countermovement jump peak force (ES = 1.73-2.01) than state-level players. Moreover, national-level players demonstrated greater (P < .05) 1-step vertical jump height (ES = 1.95, large) than second division state-level players.CONCLUSIONS: Specific anthropometric and power-related attributes clearly differ between competition levels in U19 male basketball players. This information can inform development of testing protocols, reference ranges, and training programs in practice. Further research is encouraged on this topic to confirm our findings across larger samples of basketball players.</p
Power-Related Determinants of Modified Agility T-test Performance in Male Adolescent Basketball Players.
No full textScanlan, AT, Wen, N, Pyne, DB, Stojanović, E, Milanović, Z, Conte, D, Vaquera, A, and Dalbo, VJ. Power-related determinants of Modified Agility T-test performance in male adolescent basketball players. J Strength Cond Res XX(X): 000-000, 2019-Although the Modified Agility T-test (MAT) has been advocated for assessing change-of-direction performance in basketball, the power-related attributes emphasized during the test are unknown. Therefore, the aim of this study was to identify the power-related determinants of the MAT in basketball players. A cross-sectional, descriptive research design was used whereby national- and state-level male adolescent basketball players (n = 24; 17.3 ± 0.5 years) completed a battery of power-related performance tests. The tests administered included the MAT, isometric midthigh pull, 10-m sprint, countermovement jump, 1-step vertical jump, standing long jump, and repeated lateral bound. Associations between performance during the MAT and other tests were quantified, and performance in each test was compared between faster (>50th percentile) and slower (<50th percentile) players in the MAT. The MAT exhibited large correlations (p < 0.05) with standing long jump distance (r = -0.67, R = 45%), countermovement jump relative peak force (r = -0.63, R = 39%), isometric midthigh pull relative peak force (r = -0.55, R = 30%), and 10-m sprint time (r = 0.53, R = 28%). The faster group performed better (p < 0.05) during the standing long jump (mean difference; ±90% confidence limits: 0.16; ±0.12 m) and produced greater (p < 0.05) relative peak force during the isometric midthigh pull (2.5; ±2.3 N·kg) and countermovement jump (2.1; ±1.8 N·kg) than the slower group. The MAT complements other power-related tests used in basketball and stresses basketball-specific, power-related attributes in various movement planes. These data can inform training and testing approaches to optimize change-of-direction performance in basketball
