Comparison the effects of an active recovery period with three different water temperatures in blood lactate & heart rate changes after a maximal activity

Background: One of the major barriers to successful and optimal implementation of exercise activities is fatigue, which is an inevitable consequence of strenuous activities. It seems that one of the possible reasons of fatigue in strenuous exercises is accumulation of lactic acid. Methods: A number of 13 female PE students with the mean age of 21.84±1.86 year, height of 162 ±3.85 cm and weight of 57.46±8.44 kg were chosen voluntarily to participate in this study. The subjects performed the 200m Crawl swimming high intensity exercises in three different days, then one of the recovery methods, including 5 minutes of walking in cold water (20°C), walking in warm water (39 °C) and walking in mild water (28 °C) have been implemented. The blood lactate levels of subjects were measured in time intervals of before, immediately after, and at 2 and 4 minutes of recovery times with a Lactometer and lactate kits. For Data analysis we used repeated measure ANOVA and Bonferroni post hoc tests. Results: Findings of this study revealed that there were significant differences between blood lactate levels of three recovery protocols, and active recovery in cold water caused significant decrease in lactate levels compared to warm and mild water (P = 0.01). The results also showed that in recovery with cold water, there was more decrease in heart rate compared to warm and mild water temperatures (P=0.001). Conclusion: This study revealed that recovery in cold water causes more lactic acid removal from blood and highest decrease in heart rate.