The effect of antioxidant vitamins on muscle damage during a 50-mile endurance ride in horses

Plasma markers of muscle cell damage, creatine kinase and aspartate aminotransferase, were measured in the serum of 32 endurance exercised horses during a 50-mile endurance ride to determine if supplemental vitamin E singly or in combination with vitamin C could be effective in preventing exercise-induced muscle damage. Blood was collected by jugular venipuncture prior to and at 0, 23, 35, and 50 miles of a 50-mile endurance ride. Both creatine kinase and aspartate aminotransferase increased significantly pre-exercise to post-exercise in both vitamin E and vitamin E plus C groups. Vitamin E plus C was no more effective in preventing muscle damage than vitamin E alone. Additionally, performance times were not different between groups, indicating that although muscle damage did occur during the 50-mile endurance ride, the damage did not have an adverse affect on performance