A study appearing in the British Journal of Nutrition (2008, 100: 903-9097) looked at coenzyme Q10 supplementation and muscle damage after intense exercise. This was a double-blind, placebo controlled study involving 18 athletes who were given either 300 mg of CoQ10 or a placebo for 20 days. During the course of the study they exercised intensely for 51/2 hours each day for six days. Blood tests to indicate the level of muscle damage were taken (myoglobin, and creatine kinase). The muscle-damage indicators increased in both groups, but were significantly lower in the group receiving the supplement.
Another double-blind, placebo-controlled study, appearing in the Journal of the International Society of Sports Nutrition (2008; 5(1): 8) looked at CoQ10 supplementation and athletic performance. The participants of the study were 22 trained athletes and 19 untrained subjects. An hour before a series of exercise tests they were randomly given either a placebo or 200 mg of Coenzyme Q10. Blood samples and muscle biopsies were taken before and after exercise. The subjects were then given either a placebo or 100 mg of Coenzyme Q10 twice each day for a period of two weeks. At the end of the period they performed the same exercises and were tested in the same way. A trend for increased time to exhaustion was observed following 2 weeks of CoQ10 supplementation.