Abstract
BACKGROUND: This study investigated the effect of fermented milk supplementation on glucose metabolism associated with muscle damage after acute exercise in humans. METHODS: Eighteen healthy young men participated in each of the three trials of the study: rest, exercise with placebo, and exercise with fermented milk. In the exercise trials, subjects carried out resistance exercise consisting of five sets of leg and bench presses at 70-100% 12 repetition maximum. Examination beverage (fermented milk or placebo) was taken before and after exercise in double-blind method. On the following day, we conducted an analysis of respiratory metabolic performance, blood collection, and evaluation of muscle soreness. RESULTS: Muscle soreness was significantly suppressed by the consumption of fermented milk compared with placebo (placebo, 14.2 ± 1.2 score vs. fermented milk, 12.6 ± 1.1 score, p < 0.05). Serum creatine phosphokinase was significantly increased by exercise, but this increase showed a tendency of suppression after the consumption of fermented milk. Exercise significantly decreased the respiratory quotient (rest, 0.88 ± 0.01 vs. placebo, 0.84 ± 0.02, p < 0.05), although this decrease was negated by the consumption of fermented milk (0.88 ± 0.01, p < 0.05). Furthermore, exercise significantly reduced the absorption capacity of serum oxygen radical (rest, 6.9 ± 0.4 μmol TE/g vs. placebo, 6.0 ± 0.3 μmol TE/g, p < 0.05), although this reduction was not observed with the consumption of fermented milk (6.2 ± 0.3 μmol TE/g). CONCLUSION: These results suggest that fermented milk supplementation improves glucose metabolism and alleviates the effects of muscle soreness after high-intensity exercise, possibly associated with the regulation of antioxidant capacity.