The effects of moderate prior exercise and varied rest intervals upon cardiorespiratory endurance performance

Female subjects (n=20) aged 18-25 performed PE consisting of a treadmill run designed to raise HR to approximately 140 bpm, which was maintained for 2 minutes. After the PE, the subjects rested for 30, 60, 90, and 120 seconds before starting an all-out run on a treadmill to exhaustion. They also performed the CT once without any PE. It was found that performance following PE+30 was significantly better than no PE, PE+90, and PE+120. Although PE+60 just missed being significantly better than no PE, it was significantly better than PE+90. The improved performance following PE+30 and PE+60 was attributed to the mobilization of the O₂ transport system during PE which reduced the O₂ deficit at the beginning of the CT, leaving more of the anaerobic capacity for use later in the CT. The poorer performance following PE+90 and PE+120 suggests that the mobilization effect of PE is probably lost during the longer rest intervals.