Exercise: Vitamins C and E Supplements May Affect Endurance Training.

A recent study suggests that athletes should stay away from vitamins C and E as these supplements may hinder endurance training. The study involved participants who were randomly selected to receive 1000mg of vitamin C and 235mg of vitamin E or a placebo pill daily for 11 weeks. The results revealed that markers for the production of new muscle mitochondria only increased in those who received the placebo pill.
Journal of Physiology, February 2014