Reducing exercise-induced muscular injury in kendo athletes with supplementation of coenzyme Q₁₀

Intensive physical exercise may cause muscular injury and increase oxidative stress. The purpose of this study was to examine the effect of an antioxidant, coenzyme Q₁₀ (CoQ₁₀), on muscular injury and oxidative stress during exercise training. Eighteen male students, all elite Japanese kendo athletes, were randomly assigned to either a CoQ₁₀ group (n 10) or a placebo group (n 8) in a double-blind manner. Subjects in the CoQ₁₀ group took 300 mg CoQ₁₀ per d for 20 d, while subjects in the placebo group took the same dosage of a placebo. All subjects practised kendo 5.5 h per d for 6 d during the experimental period. Blood samples were taken 2 weeks before, during (1 d, 3 d, 5 d) and 1 week after the training. Serum creatine kinase (CK) activity and myoglobin (Mb) concentration significantly increased in both groups (at 3 d and 5 d). Serum CK (at 3 d), Mb (at 3 d) and lipid peroxide (at 3 d and 5 d) of the CoQ₁₀ group were lower than those of the placebo group. The leucocyte counts in the placebo group significantly increased (at 3 d) and neutrophils significantly increased in both groups (at 3 d and 5 d). Serum scavenging activity against superoxide anion did not change in either group. These results indicate that CoQ₁₀ supplementation reduced exercise-induced muscular injury in athletes.