production combined with environmental heat and humidity challenges the body’s heat dissipation mechanisms. In addition, in summer months, heat dissipation during the swim phase may be affected by the warm water temperature (>29 °C) ( 11 ), which may lead to dangerous elevations in core temperature ( T c
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Hydration and Performance in Young Triathletes During a Competition in Tropical Climate
Anita M. Rivera-Brown and Patricia Pagán-Lassalle
Time-of-Day Effects on Short-Term Exercise Performances in 10- to 11-Year-Old Boys
Hichem Souissi, Anis Chaouachi, Karim Chamari, Mohamed Dogui, Mohamed Amri, and Nizar Souissi
The purpose of this study was to examine the time-of-day effects on short-term performances in boys. In a balanced and randomized study design, 20 boys performed four anaerobic tests of strength and power (grip strength, Squat-Jump, Five-jump and cycle Wingate tests) at 08:00, 14:00 and 18:00 hr on separate days. The results showed a time-of-day effect on oral temperature. Analysis of variance revealed a significant time-of-day effect for short-term performances for strength, cycle, and jump tests. The post hoc analysis revealed that performances improved significantly from morning to afternoon but no significant differences were noticed between 14:00 and 18:00 hr. The differences between the morning and the afternoon (the highest value measured either at 14:00 or at 18:00 hr) reached 5.9% for grip strength, 3.5% for the squat jump test, 5% for the five jump test, and 5.5% for Ppeak and 6% for Pmean during the Wingate test. A significant positive correlation was found between temperature and short-term performances. In conclusion, a time-of-day effect in the child’s maximal short-term exercise performances exists in relation with core temperature. Such variations would have pronounced effects when expressed in training programs and competitions.
Skin Blood Flow Responses to Acetylcholine, Local Heating, and to 60% VO2max exercise with and without Nitric Oxide inhibition, in Boys vs. Girls
Raffaele Joseph Massarotto, Gary J. Hodges, Alexandra Woloschuk, Deborah D. O’Leary, Raffy Dotan, and Bareket Falk
thermoregulatory responses (core temperature and HR) among individuals of differing V ˙ O 2 max ( 20 ). In addition, exercise intensity and duration were based on Rowland et al ( 42 ), who demonstrated a similar increase in body temperature (<1°C) in boys and men following 30 minutes of cycling at 65% V ˙ O 2
Children With Cardiac Disease and Heat Exposure: Catastrophic Converging Consequences?
Luc Souilla, Pascal Amedro, and Shawnda A. Morrison
). Higher fitness elicits efficient heat balance since fitter people sweat more and can tolerate higher core temperatures ( 24 ) than unfit people. There are multiple structural and functional cardiovascular adaptations which lessen external system demands when people move in the heat ( 28 ) (Figure 2
Reliability, Validity, and Performance Characteristics of Elite Adolescent Athletes at Different Stages of Maturity in the 10 to 5 Repeated Jump Test
James Baker, Barry Shillabeer, Christopher Brandner, Philip Graham-Smith, Patrick Mills, and Paul Read
-PHV (between −1.0 and 1.0 y from PHV), and post-PHV (>1.0 y from PHV) for analysis. Procedures All participants completed a standardized warm-up including running 2 laps of an indoor athletics track at a self-determined 50% of the athlete’s maximal speed for the elevation of core temperature. Following this
