Effects of physical exercise on fruit fly, Drosophila melanogaster were quantified in two environmental conditions. First, in the natural light-dark (NLD) cycles with fluctuating temperature and relative humidity and second, at constant temperature of 25°C, relative humidity of 65±10% and light intensity of 100 lux. It was observed that, in the NLD conditions the flies walking on a single cotton thread were subjected to an extensive physical exercise and hence they exhibited a lifespan of ~59 days while the flies walking on the double cotton threads and the double nylon threads were subjected to least degree of exercise, their lifespan was of just ~30 days. Flies maintained at 25°C, nevertheless, had entirely different life span vis-à-vis (in relation) to the characteristic of the threads. The flies walking on the double nylon threads when subjected to extensive physical exercise, they exhibited the longest lifespan of ~35 days. Whereas the flies walking on a single and double cotton threads were subjected to least degree of exercise, their lifespan was observed to be of only ~22 days. These results demonstrate that the exercise has profound influence on the lifespan of Drosophila which has indisputable implication in human health too. Furthermore, natural light-dark cycles with fluctuating temperature and relative humidity have life enhancing effect than the constant temperature conditions.