In the present pushbutton era most of the adolescent are not participating in leisure activities and concentrate are on studies. Regular physical activity would be important for life’s quality even if it had no relationship to disease and longevity. Physical activity is a significant ingredient in the quality of life, because it increases energy and promotes, physical and mental well being in addition to conferring health benefits. Boys from various schools of [Tripura (TR), Meghalaya (ML), Assam (AS), Mizoram (MZ), Manipur (MN), Nagaland (NL) and Arunachal Pradesh (A.R.)] (N=21000) North-Eastern states of India were selected as subjects at random. Their age ranged from 13 to 15 years (studying from 7th to 10th standard). Muscular endurance was measured by the number of sit-ups in a one minute. The collected data were analyzed by using one-way ANOVA. Among the groups, if any significant difference, scheffe’s post hoc test was used to find out the paired mean difference (P ? 0.05). The results of the study show that the adolescent boys of North-Eastern states were differ on muscular endurance. Hence it was concluded that, age, geographical region, growth, social behaviour, food habits and level of physical activity may influence the muscular endurance of adolescent boys.