RELATIONSHIP BETWEEN MUSCLE SORENESS AND CONTRACTILE PERFORMANCE FOLLOWING DOWNHILL RUNNING

Abstract

Downhill running has consistently been shown to result in increased muscle soreness and damage; however, its effects on contractile performance are less clear. The purpose of this investigation was to examine the relationship between muscle soreness and contractile performance following downhill running (DHR). Ten male subjects (age = 23 ± 1 years, height = 1.81 ± 0.02m, weight = 87.5 ± 3.1kg) ran at a −10% grade for 30 min at 80% predicted maximum heart rate. Subjects were evaluated for perceived muscle soreness (MS) of the front and back of the dominant leg, pressure pain threshold (PPT) by dolorimetry of 4 locations on the thigh (the anterior medial, anterior lateral, posterior medial, and posterior lateral quadrants), peak knee extension (KE)/flexion (KF) torque and power at 3 speeds (90°/s, 180°/s, and 300°/s), and shuttle run time (SRT) immediately prior to DHR and 24 post-DHR. All variables were negatively affected as a result of DHR. Correlation analyses indicated that the relative change in PPT in the anterior lateral quadrant was negatively related to knee extension torque at 90°/s (r = −0.76, p = 0.01) and knee flexion torque at 180°/s (r = −0.67, p = 0.04). Furthermore, increases in shuttle run time (SRT) were related to declines in PPT in the anterior medial (r = 0.69, p = 0.02), posterior medial (r = 0.64, p = 0.04), and posterior lateral (r = 0.63, p = 0.05) quadrants. In comparison, changes in perceived MS were not correlated with any measure of contractile function. These results suggest that changes in PPT may be more effective at predicting changes in contractile performance due to muscle damage than perceived MS.