Researchers in China examined the effect of vitamins E and C on the exercise performance of rats (Di Yi Jun Yi Da Xue Xue Bao  2003; 23(9):892-4 (ISSN: 1000-2588). Fifty rats were divided into four groups, one group was given vitamin C, one was given vitamin E, one was given a combination of vitamins C and E, and the fourth group, the control, was given no supplementation. The rats given vitamin E in combination with vitamin C  were able to exercise longer and had greater muscle mass in the quadriceps muscles after 4-weeks of exercise when compared to the control group. The rats taking oral vitamin C or E alone did not experience these improvements. Vitamin E is the major fat-soluble antioxidant in cell membranes. It is recycled by a reaction with vitamin C.