The aim of the present study was to investigate whether children showed similar signs of muscle overuse like adults after intense exercise. One child group (n = 10) and one adult group (n = 10) of males both had to perform five series of bench press exercises at an intensity of 80% of maximum strength until exhaustion. Maximum isometric strength, subjective perception of muscle pain, was measured before, immediately after, 48 hr, 72 hr, and 1 week after the exercise. Serum creatine kinase (CK) activity was measured before, 48 hr, 72 hr, and 1 week after the exercise. The adults showed all symptoms of muscle overuse: reduced strength, muscle pain, and elevated CK activities until 3 days after the exercise. In contrast, the children experienced only some light muscle pain, but neither showed reduced strength nor elevated CK activities. It is concluded that children’s muscles can easier withstand physical stress than adult muscles.
José M.C. Soares, Paulo Mota, and José A. Duarte are with the Department of Sport Biology, Faculty of Sport Sciences, Praça Pedro Nunes, P-4000 Porto, Portugal. Hans J. Appell is with the Institute for Sport Orthopedics at the German Sport University, D-50927 Cologne, Germany.