Exercise is associated with increased oxidative stress that, if not countered, can cause suboptimal adaptations to training. One supplement that has the potential to minimize oxidative stress is CoQ10. CoQ10 functions in the mitochondria, the "powerhouses" of the cell to assist in making energy (ATP) from carbohydrates and fats. CoQ10 primarily acts as an antioxidant and is involved in the synthesis of energy (ATP), but also has other important functions inside the mitochondria such as stabilizing membranes. Because of CoQ10's role in oxidative stress, energy production, and stabilization, it is useful in preventing damage to muscle during periods of stress. In fact, CoQ10 has been used in prevention and treatment of cardiovascular disease in heart patients for decades, but its role in preventing exercise-induced stress has not been examined. Japanese researchers studied the effects of CoQ10 supplementation in elite Japanese kendo athletes. The subjects were assigned to either take 300 mg CoQ10/day or placebo for 20 days. The subjects were training intensely an average of 5.5 h per day for 6 days per week. Blood analyses indicated that the CoQ10 group had lower levels of lipid peroxides indicating significantly lower oxidative stress. CoQ10 supplementation also resulted in lower concentrations of two markers of muscle membrane damage, creatine kinase activity and myoglobin, compared to the placebo group. These are promising results showing the potential value of CoQ10 supplementation in reducing exercise-induced oxidative stress and muscle damage.

Kon M, Tanabe K, Akimoto T, Kimura F, Tanimura Y, Shimizu K, Okamoto T, Kono I. Reducing exercise-induced muscular injury in kendo athletes with supplementation of coenzyme Q10. Br J Nutr. 2008 Feb 20;:1-7 [Epub ahead of print]