Author(s): LIU, C., Institution: CHANG JUNG CHRISTIAN UNIVERSITY, Country: TAIWAN, Abstract-ID: 1968

INTRODUCTION:
Athletes may experience different fatigue responses when training under varying environmental temperatures. This study examines the effects of training under high-temperature conditions (average ~35°C) and comfortable-temperature conditions (average ~22°C) on lower-body explosive performance, as assessed by countermovement jump (CMJ) performance, following identical training loads (RPE 6-8).
METHODS:
Thirteen participants, all university rugby players with regular training habits, were recruited for this study. The participants had an average height of 174.27±3.25 cm and body weight of 71.86±7.99 kg. Each participant completed one week of training under each environmental condition, with daily training sessions lasting approximately two hours and maintaining consistent training loads. CMJ tests were conducted before each training session, recording jump height (cm) as an indicator of fatigue. Data analysis compared the trends in CMJ performance across different temperature conditions to evaluate the impact of environmental temperature on post-exercise fatigue. Paired-sample t-tests were conducted, with statistical significance set at .05.
RESULTS:
Preliminary data showed a significant decrease in CMJ performance under high-temperature conditions (average decrease of 2.5±1.2 cm, p < .05), whereas CMJ values remained more stable in the comfortable-temperature environment (change of 0.5±0.8 cm, p = .12), with some participants even maintaining or improving their performance. Additionally, greater variability in CMJ scores was observed in the high-temperature condition, possibly related to individual heat tolerance and hydration status.
CONCLUSION:
The results indicate that high-temperature environments may exacerbate fatigue accumulation and negatively impact lower-body explosive performance, even when training loads are consistent. These findings have practical implications for sports training and competition planning, suggesting that enhanced recovery strategies and fatigue monitoring should be implemented to mitigate performance declines in high-temperature conditions.