The serum lactate levels were evaluated after 2 weeks of MMP treatment, 30 minutes after the final oral administration, the mice were forced to swim for 10 minutes without any weight loading. The fatigue-related variables were assessed under fasting conditions to reflect the real physiological adaptation during the acute exercise challenge. Under fasting conditions, we examined blood lactate concentrations in mice before exercise, after 10 min swimming exercise, and 20 min rest during the acute exercise challenge. Serum samples were obtained by centrifugation of blood samples at 1000× g for 15 minutes at 4 °C and were analyzed by an autoanalyzer (Hitachi 7060, Hitachi, Tokyo, Japan). Besides, the lactate production rate was calculated as the post-exercise rate divided by the before exercise rate (B/A), and the lactate difference between the post-exercise rate and the post-rest rate divided by the post-rest rate was defined as the clearance rate.