| Vitamin C, vitamin E (tocopherols), and some | | | | time, it appears that the production of ROS by cells |
| precursors to vitamin A (the carotenoids) exhibit | | | | of the immune system may be an important part of |
| antioxidant activity. Each of these vitamins has | | | | the post-exercise muscle repair process. Neutrophils |
| independently been shown to alter immunity. The | | | | and macrophages appear to infiltrate sites of |
| antioxidant function of these vitamins is of interest | | | | post-exercise muscle damage and both of these cell |
| to some athletes primarily because exercise increases | | | | types produce ROS. The release of ROS can |
| the production of reactive oxygen species (ROS) | | | | enhance the release of cytokines and cytokines can |
| which have been associated with muscular fatigue | | | | induce the production of ROS The release of both |
| and muscular damage. In addition, neutrophils and | | | | cytokines and ROS are important in removing |
| macro phages produce ROS. The ROS produced by | | | | damaged muscle tissue and may assist in the repair |
| the immune system may have a role in modulating | | | | process. The findings from a recent study suggest |
| post-exercise muscle damage. | | | | that the generation of ROS post-exercise may be |
| The other reason that vitamins A, C, and E may be | | | | beneficial in the repair process. In this study, normal |
| of interest to athletes relates to their potential | | | | mice demonstrated greater oxidative stress |
| immunostimulatory properties. The antioxidant | | | | post-exercise than mice with inhibited neutrophil |
| properties of the vitamins may differ from the | | | | function; however, 4 days later normal mice showed |
| immunomodulatory effects. | | | | evidence of less muscle damage Based on this |
| Reactive oxygen species (ROS) are produced during | | | | evidence and findings from other studies mentioned |
| strenuous exercise, result in oxidative stress, and are | | | | previously, it should be noted that the production of |
| associated with a depletion of antioxidants, muscle | | | | free radicals or ROS during exercise may be an |
| damage, and fatigue. High concentrations of | | | | important part of the muscle tissue repair process |
| antioxidants may protect against the damaging | | | | and the consumption of high levels of antioxidants |
| effects of ROS. An assumption has been made that | | | | may not necessarily be beneficial. |
| a high intake of vitamins A, C, E, or betacarotene | | | | Some researchers have examined life span and |
| may protect against the exercise-induced oxidative | | | | whether it can be extended by increased antioxidant |
| stress and several studies have examined this | | | | intake. The evidence from two recent studies |
| possibility. Vitamin E (alpha-tocopherol) is considered | | | | suggests that supplementing diets with high levels of |
| the most important scavenger of ROS at the level | | | | antioxidants does not increase maximum life span and |
| of membranes and is probably the most well studied | | | | exercised rodents fed a diet containing additional |
| with respect to exercise. | | | | antioxidants did not have a greater life span than |
| Several studies have established that exercise training | | | | exercised rodents on a normal diet. It appears that |
| is associated with a decrease in the accumulation of | | | | although exercise may be associated with a greater |
| the products used to assess oxidative stress or an | | | | production of ROS, this does not result in a |
| enhancement of antioxidant enzymes. The findings | | | | shortened life span and the consumption of additional |
| from some studies suggest that vitamin E | | | | antioxidants confers no additional increase in |
| supplementation may protect against the oxidative | | | | longevity. |
| damage induced by exercise. However, the results | | | | Taken together, the findings from the studies above |
| from both human and animal studies show that | | | | suggest that additional antioxidants do not improve |
| vitamin E supplementation does not improve | | | | performance, do not appear to improve muscle |
| performance and may not attenuate muscular | | | | tissue repair post-exercise, and are not beneficial in |
| damage following a marathon. | | | | terms of increasing life span in exercised rodents. |
| An understanding of interactions between the | | | | Although the interactions between the immune |
| immune system, ROS production, and muscle damage | | | | system and ROS produced during exercise need |
| may provide some insight regarding antioxidants and | | | | further research, at this time it does not appear that |
| exercise-induced muscle damage. Although these | | | | additional antioxidants will enhance immune responses |
| interactions are not completely understood at this | | | | such as post-exercise muscle tissue repair. |