Association of abdominal endurance with body adiposity, physical activity and sitting time in adolescents

Objective: Identify possible associations of muscular endurance with body adiposity, physical activity, and sedentary behavior in adolescents. Methods: A cross-sectional study was conducted on a sample of 1773 adolescents (795 boys and 978 girls) aged 14 to 19 years from Florianopolis, Brazil. Abdominal endurance by the sit-up test proposed by the Canadian Physical Activity, Fitness and Lifestyle Assessment Approach. Body adiposity was estimated by the sum of triceps and subscapular skinfold thicknesses. Daily physical activity was estimated by the International Physical Activity Questionnaire - Short Form. Sedentary behavior was investigated using a self-report questionnaire, taking into account the time spent sitting on a weekday and a weekend day. Stepwise linear regression analysis was performed to identify the predictors of abdominal endurance. Results: Boys (16,43 years) were more active (94.85 min/day vs 84.30 min/day, p < 0.001) and had higher abdominal endurance (23.67 repetitions vs 21.31 repetitions, p < 0.001) than girls. Girls (16,27 years) had a longer sitting time (414.89 min/day vs 376.12 min/day, p < 0.001) and higher body adiposity (31.69 mm vs 21.44 mm, p < 0.001) than boys. As for predictors, body adiposity (β = −0.207) was the only variable associated with abdominal endurance in boys, whereas body adiposity (β = −0.127) and physical activity (β = 0.099) were associated with abdominal endurance in girls. Conclusion: In both sexes, high levels of body adiposity negatively affect abdominal endurance. On the other hand, in girls, high levels of physical activity have a positive influence on abdominal endurance.