Yellow/Orange foods are high in beta-cryptoxanthin and beta-carotene, which is a particularly good antioxidant.  Results from a study on the effect of beta-carotene on race performance published in the journal Medicine and Science in Sports and Exercise indicated that there was a statistically significant improvement in 5 kilometer race performance. The average race times during the placebo and beta-carotene phases were 19:55 minutes and 19:18 minutes respectively. In addition, 64% of the subjects noted a subjective benefit from the use of beta-carotene supplementation (4). Beta-cryptoxanthin, beta-carotene, and alpha-carotene are all orange-friendly carotenoids and can be converted in the body to vitamin A, a nutrient integral for vision and immune function, as well as skin and bone health. While supplementation is one way to get these nutrients getting them from real whole foods is the ideal way for your body to process these nutrients. Click here for a great summer carrot soup recipe