The purpose of this study is to know the effect of pre-cooling strategy using 3mg of melatonin during daytime on tympanic temperature, heart rate and endurance capacity. Twenty four physically active and healthy males were randomly classified into two groups namely melatonin and placebo, each constitute of 12 players. The age, height and body mass were 21.13 ± 0.80 yr, 1.79 ± 0.5 m, 78.4 ± 5.1 kg, respectively. Tympanic temperature, heart rate and endurance capacity was selected as criterion variable. Single dose of Melatonin (3g) and placebo were supplemented to respective group around 10:00. ANCOVA was administered. The results of this study indicate that the 3 mg of melatonin significantly affected the tympanic temperature (F (1&21) = 12.68, p = 0.002) and heart rate (F (1&21) = 6.48, p = 0.019). However endurance capacity did not show any changes (F (1&21) = 2.308, p = 0.144). It is inferred from the results of the present study that 3mg of melatonin significantly affect the tympanic temperature and heart rate but failed to show any impact on endurance capacity.


Melatonin, Placebo, Heart rate, Tympanic temperature, Endurance and athletes,


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