The aim of the present study was to investigate the effect of warm-up and cool-down exercise on delayed onset of muscle soreness at the distal and central parts of rectus femoris following leg resistance exercise. Thirty-six volunteers (21 women, 15 men) were randomly assigned to the warm-up (20 min ergometer cycling prior to the resistance exercise), cool-down (20 min cycling after the resistance exercise), or control group performing resistance exercise only. The resistance exercise consisted of front lunges (10×5 repetitions/sets) with external loading of 40% (women) and 50% (men) of body mass. Primary outcomes were pressure pain threshold along rectus femoris and maximal isometric knee extension force. Data were recorded before the resistance exercise and on the two consecutive days. Pressure pain threshold at the central muscle belly was significantly reduced for the control group on both day 2 and 3 (p≤0.003) but not for the warm-up group (p≥0.21). For the cool-down group, pressure pain threshold at the central muscle belly was significantly reduced on day 2 (p≤0.005) and was also lower compared to the warm-up group (p=0.025). Force was significantly reduced on day 2 and 3 for all groups (p<0.001). This study indicates that aerobic warm-up exercise performed prior to resistance exercise may prevent muscle soreness at the central but not distal muscle regions, but it does not prevent loss of muscle force.
Keywords: aerobic exercise; athletic injuries; muscles; pain; pain threshold.