Abstract: Objective: To investigate Greco-roman wrestling athletes’ heat adjustment in hot and humid environment and the effect of rehydration. Methods: 8 wrestling athletes, aged 16.1±2.3, having VO₂max of 44.5ml/kg/min and trained for 3.8±1.7 years, were chosen as subjects. The subjects were arranged to do exercises respectively in environment of normal temperature and humidity, in hot and humid environment and in hot and humid environment with rehydration. The interval between every two exercise processes was 10 days and the exercise intensity was 70%VO₂max. Athletes’ core body temperature was tested before and after every experiment, and their blood lactic acid and heart rate were tested during the experiments, and their sweat was collected for the test of sweat electrolytes before and after every experiment. Results: (1) In hot and humid environment, athletes’ core body temperature, blood lactic acid, heart rate and sweat ion density were all significantly higher than in environment of normal temperature and humidity, while athletes’ exercise duration becomes much shorter; (2) In hot and humid environment, rehydration can dramatically lower athletes’ core body temperature, while increase athletes’ exercise duration. Conclusion: hot and humid environment can generate a significant influence on athletes’ exercise ability. Their core body temperature, blood lactic acid, heart rate increase significantly, their sweat ion loss is obvious, and their exercise duration becomes shorter. rehydration has a positive role in reducing the loss of sweat ion and maintaining exercise ability.

Key words: Hot and Humid Environment, Greco-Roman Wrestling Athlete, Exercise, Heat Adjustment, Rehydration