Introduction: Isotonic exercise has a range of beneficial effect on the sperm vitality depending upon the intensity, duration of activity and fitness of the individual. But further research is required.

Methodology: Study was carried out in 90 subjects subdivided into Group A – sedentary healthy males (30), Group B– healthy males involved in regular isotonic exercises for last 1 year and Group C– healthy males who were involved in regular isotonic exercises for at least 5 years (30). Sperm vitality in all subjects was assessed using Eosin– Nigrosin staining method and was compared among 3 groups. The data was analyzed and compared using 1 way Anova and Bonferroni‘s multiple comparison test.

Results: Mean sperm vitality (%) was statistically significant in Group B (mean =78.4 ±4.14) as compared to Group A (mean =59.6 ± 15.47) and Group C (Mean =55.5 ± 14.51). There was no statistically significant difference in the mean sperm vitality (%) between Group A and Group C.

Conclusion: Short term moderate intensity isotonic exercises increase the sperm vitality. Long term moderate intensity isotonic exercise shows no significant effect on the sperm vitality.