The effect of eight-week of interval training on plasma levels of melatonin in inactive elderly men

Melatonin plays an important role in rhythmic processes that decreases its secretion due to aging. The aim of this study was to investigate the effect of eight-week of interval training on plasma levels of melatonin in inactive elderly men.

In this quasi-experimental study, 20 inactive elderly men were selected by available sampling and randomly divided into experimental (n=10) and control (n=10) groups. For evaluation of the effect of aging on melatonin levels, 10 inactive young men were selected by purposive sampling. The training protocol consisted of eight weeks of interval training with an intensity of 50% reserve heart rate (activity period) and 30% reserve heart rate (rest period). Plasma melatonin levels were measured by ELISA method in pre and post test. To compare the pre-test of the three groups the ANOVA test was used and to compare the post-test of the two groups of training elderly and control elderly the analysis of covariance at a significance level of 0.05 was used.

The results showed that aging leads to a significant reduction in plasma melatonin levels (p<0.05). There was a significant inverse relationship between age and melatonin levels (r=-0.824 and p=0.001). Also, eight weeks of interval training significantly increased melatonin levels in older men in the training group (p<0.05).

Physical activities especially interval training with increasing the melatonin levels, can reduce or slow down the changes caused by decreased melatonin secretion and related changes in the body systems in old age.