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


  1. G. Atkinson, B. Drust, T. Reilly, J. Waterhouse, The relevance of melatonin to sports medicine and science, Sports Medicine, 33 (2003) 809–831.
  2. G. Atkinson, A. Holder, C. Robertson, N. Gant, B. Drust, T. Reilly, J. Waterhouse, Effects of melatonin on the thermoregulatory responses to intermittent exercise, Journal of Pineal Research 39 (2005) 353–359.
  3. A. Cagnacci, K. Kräuchi, A. Wirz-Justice, A. Volpe, Homeostatic versus circadian effects of melatonin on core body temperature in humans. Journal of Biological Rhythms, 12 (1997) 509–517.
  4. D. Dawson, S. Gibbon, P. Singh, The hypothermic effect of melatonin on core body temperature: is more better? Journal of Pineal Research, 20 (1996) 192–197.
  5. D. Dawson, C.J. Van Den Heuvel, Integrating the actions of melatonin on human physiology, Annals of Medicine, 30(1) (1998) 95–102.
  6. C. Foster, A.S. Jackson, M.L. Pollock, M.M. Taylor, J. Hare, M. Sheila, Sennett, J.L. Rod, M. Sarwar, D.H. Schmidt, Generalized equations for predicting functional capacity from treadmill performance. American Heart Journal, 107 (1984) 1229- 1234.
  7. K. Kräuchi, C. Cajochen, A. Wirz-Justice, A relationship between heat loss and sleepiness: effects of postural change and melatonin administration, Journal of Applied Physiology, 83 (1997) 134–139.
  8. J. Waterhouse, B. Drust, D. Weinert, B. Edwards, W. Gregson, G. Atkinson, S. Kao, S. Aizawa, T. Reilly, The circadian rhythm of core temperature; origin and some implications for exercise performance, Chronobiology International, 22 (2005) 207– 225.
  9. W. Gregson, B. Drust, A. Batterham, N.T. Cable, The effect of pre-warming on the metabolic and thermoregulatory responses to prolonged submaximal exercise in moderate ambient temperatures, European Journal of Applied Physiology, 86 (2002) 526–533.