Sports Fitness Training

In the athlete, it appears that the most promising characteristic of antioxidant supplementation regarding performance is the ability to aid recovery As athletes know, recovery after exercise is vitally important to improved performance. Eccentric contractions (i.e., “negatives”) are a necessary part of many types of sport and result in exaggerated myofibrillar disruption, delayed-onset muscle soreness, inflammation, and reduced force generation. Thus, decreasing muscle damage and inflammation (and/ or hastening a return to “healthy” status) can allow an athlete to resume training and more rapidly improve in ability The response to muscle damage can last several days and is hallmarked by increased muscle enzyme release, urinary nitrogen excretion, increased metabolic rate, and increased cortisol and interleukin concentrations. Subjects also experience decreased glucose tolerance and strength after eccentric exercise This period of eccentric recovery is in stark contrast to the shorter, less traumatic 24-48 hour recovery period observed after less-damaging concentric exercise. As mentioned earlier, circulating leukocytes (white blood cells) infiltrate traumatized muscle tissue and, in concert with cortisol, prostaglandins, and various cytokines, they induce catabolism, edema, pain, and inflammation. Although this immune response is primarily beneficial, the period of catabolism may be unnecessarily aggressive before growth factors are secreted and tissue growth and/or repair begins.Think of this scenario as equivalent to a group of janitors arriving to clean up a mess. But, in addition to cleaning up the original mess, these janitors (neutrophils and monocytes) also tend to tear down the walls as they clean. Antioxidant vitamins like vitamin E and vitamin C may combat this aggressive cleaning strategy of the janitors (part of the acute-phase response) both by buffering the reactive oxygen species that are released and by suppressing cell membrane peroxidation and prostaglandin formation, which is partly responsible for the inflammation. The next logical question would be, Why would anyone punish themselves with eccentric contractions to the point of requiring pharmacologic doses of vitamins The logic behind using repeated, high-intensity eccentric contractions involves the growth response. Because the muscle hypertrophic response is greater, athletes requiring gains in muscular size and/or strength often use negative training using resistance exercises and/ or plyometrics. As we have seen, this can aggravate oxidant insult, inducing damage that might only be treated optimally with antioxidant supplementation