THE EFFECTS OF EXERCISE-INDUCED MUSCLE DAMAGE ON AGILITY AND SPRINT RUNNING PERFORMANCE

The purpose of this investigation was to assess the effects of exercise-induced muscle damage (EIMD) on agility and linear sprint running performance. Twelve healthy adults were randomly allocated to a treatment group (n = 7; age, 21 +/- 1.2 years', height, 1.77 +/- 0.11 m(-1) body mass, 70.8 +/- 8.2 kg) where they completed 100 plyometric jumps, or to a control group (n = 5; age, 24 +/- 0.7 years; height, 1.77 +/- 0.07 m; body mass, 69.2 +/- 8.8 kg). Perceived muscle soreness, isokinetic peak torque of the knee extensors at 60 and 270 deg . s(-1), sprint running time over 5 and 10 m, a timed agility test and ground contact time at the agility turn point were recorded at baseline and then 24, 48 and 168 hours Following muscle-damaging exercise. Perceived muscle soreness was significantly increased (p < 0.05) and isokinetic peak torque at 60 and 270 deg . s(-1) was significantly decreased (p < 0.05) at 24 and 48 hours in the treatment group following plyometric exercise. Significant increases (p < 0.05) were also observed for 5 m (6%) and 10 m (5%) sprint time, agility time (8%) and ground contact time at the agility turn point (21%), peaking at 48 hours in the treatment group. All variables remained unchanged in the control group (p > 0.05). These findings indicate that agility and sprint performance is reduced following EIMD, and provides further evidence that performance of activities requiring rapid generation of force is impaired following muscle-damaging exercise. [J Exerc Sci Fit . Vol 7 . No 1 . 24-30 . 2009]