RESUMO
BACKGROUND: During competition, high-performance swimmers are subject to repeated physical demands that affect their final performance. Measurement of lactate concentration in blood seeks to indirectly gauge physiologic responses to the increase in physical exercise. Swimmers face multiple maximal-exertion events during competition. Strenuous physical exercise leads to fatigue and, thus, a decrease in sports performance. HYPOTHESIS: Regeneration exercises in swimming increase the clearance of blood lactate and therefore improve athletic performance within a single day of competition. STUDY DESIGN: Crossover study. LEVEL OF EVIDENCE: Level 1. METHODS: Of 25 swimmers, 21 were included, with a mean age of 17 years. They performed exercises that increased blood lactate on 2 days. The protocol was a warm-up, followed by a 100-m freestyle workout at full speed. Swimming exercises followed that were increasingly demanding, during which serial lactatemia measurements were taken. On the first day, regeneration exercises were performed; on the second day, the swimmers rested. Next, lactatemia was measured, and a timed 100-m freestyle workout was performed at maximum speed. RESULTS: The stress exercises increased the mean lactate concentration by 4.6 mmol/L, which corresponds to 78% of the initial basal level. The postregeneration lactatemia level was lower than that after resting (mean, 2.76 vs 6.51 mmol/L). The time to swim 100 m after regeneration was 68.11 seconds, while that after rest was 69.31 seconds. CONCLUSION: Blood lactate levels rose by up to 78% after the intensity of the training sessions was progressively increased. Regeneration exercises increased the rate in which blood lactate dissipated, in comparison with passive recuperation. The rate of lactate dissipation for regeneration exercises was 68%. This factor may have improved the physical performance of swimmers. CLINICAL RELEVANCE: Regeneration exercises improved the performance of swimmers in maximal-exertion competition in a single day. The blood lactate level correlated with physical exercise load.