Eccentric exercise-induced muscle damage of pre-adolescent and adolescent boys in comparison to young men

Purpose This study compared changes in indirect muscle damage markers after maximal eccentric exercise of the elbow flexors (EF) among pre-adolescent (9–10 years), adolescent (14–15 years) and post-adolescent (20–25 years) men to test the hypothesis that the magnitude of muscle damage would increase with increase in age. Methods Thirteen untrained men of each age group performed two bouts (ECC1, ECC2) of 30 maximal EF eccentric contractions. Several indirect muscle damage markers were measured from the exercised arm before, immediately after, and 1–5 days post-exercise. Changes in maximal voluntary concentric contraction torque of the EF (MVC), range of motion of the elbow joint, upper arm circumference (CIR), muscle passive stiffness, muscle soreness, plasma creatine kinase activity and myoglobin concentration after ECC1 and ECC2 were compared amongst groups by a mixed-design two-way ANOVA. Results MVC before exercise was smaller ( P