Active recovery reduces the decrease in circulating white blood cells after exercise.

This study was conducted to examine the effects of different recovery regimens on white blood cell count (WBCC) and muscle enzyme activities following strenuous, submaximal, steady state workouts on a treadmill. Fourteen endurance trained, healthy, non-smoking college-aged males participated in the study. The workouts were followed by either 15-min of rest recovery (RR), or active recovery (AR). The AR consisted of running at 50% of VO2max whereas RR implied complete rest. Seven subjects completed two sets of 60-min running at 70% of VO2max (moderate intensity group, MI) followed by either RR or AR. The other seven completed two sets of 30-min running at 80% of VO2max (high intensity group, HI) followed by either RR or AR. Blood samples were drawn at rest, immediately after exercise, and at 15- and 120-min post-exercise (PE). Blood lactate concentrations increased throughout the running trials. Creatine kinase (CK), lactate dehydrogenase (LD), white blood cell count (WBCC) and thrombocyte count increased between rest and 0-min PE (p<0.05). Between 0-15-min PE, there were several significant differences between RR and AR in the HI-trial. RR was associated with a 35% reduction in WBCC, compared to only 6% decrease in AR (p<0.02). Neither during 15-120-min PE this period, nor in the 120-min sample alone, were there any significant differences in WBCC between the RR and AR experiments. In conclusion, the results show that AR as opposed to rest recovery prevents the initial 0-15-min PE fall in WBCC after strenuous endurance exercise.