INFLUENCE OF AGE AND BODY-MASS INDEX ON MEASURES OF PHYSICAL-FITNESS IN US ARMY SOLDIERS

This study describes associations between age, body mass index (BMI), and performance on three common measures of physical fitness: maximum push-ups in 2 min, maximum sit-ups in 2 min, and 3.2-km run for time. Subjects were 5,346 healthy male soldiers, ages 18 to 53 years. Before age 30, there were few age-related differences between the youngest a nd the older age groups on any test; after age 30, performance decline d as age increased, averaging 16%, 17%, and 7% per decade for push-ups . sit-ups. and the run, respectively. Regression analysis showed that age accounted for 10%, 15% and 9% of the variance ill push-up, sit-up, and run performances, respectively. When BMI was added to the regress ion model it increased the variance accounted for in the run to 16% (a ge plus BMI) but did not explain variance in push-ups or sit-ups. Ther e are systematic age-related declines in the performance of push-ups, sit-ups, and 3.2 km running, with age alone accounting for only 9% to 15% of the total performance variance in this sample of healthy men.