Radical protection for athletes.Competitive atheletes continually push to better their records, but such strenuous pursuits exact a price. The high consumption of oxygen bathes the body in biologically damaging, oxygen-derived free radicals. However, at least five new studies indicate that certain dietary supplements can help limit or repair muscle damage from these oxidants. All were presented last month at the American College of Sports Medicine's annual meeting in Dallas.
For instance, Christopher Baldi and his colleagues at Ithaca (N.Y.) College assayed malondialdehyde (MDA (1) (Monochrome Display Adapter) The first IBM PC monochrome video display standard for text. Due to its lack of graphics, MDA cards were often replaced with Hercules cards, which provided both text and graphics. See PC display modes and Hercules Graphics. ), a characteristic marker of muscle oxidation, in 25 college-age women before and after a vigorous, 30-minute treadmill run. The exercise raised urinary MDA levels by 32 percent in women who did not receive supplements, the researchers found. Surprisingly, postexercise MDA levels fell by 28 percent among the remaining women, all of whom had taken 400 international units of vitamin E daily for three months. This suggests that antioxidants Antioxidants
Substances that reduce the damage of the highly reactive free radicals that are the byproducts of the cells.
Mentioned in: Aging, Nutritional Supplements
n. "may actually reverse oxidative stress during exercise," concludes Robert R. Jenkins, who led the study.
Ian Gillam of the Phillip Institute of Technology in Melbourne, Australia, and his colleagues recorded signs of a similar suppression of muscle oxidation in elite, high-endurance athletes after just four weeks of antioxidant antioxidant, substance that prevents or slows the breakdown of another substance by oxygen. Synthetic and natural antioxidants are used to slow the deterioration of gasoline and rubber, and such antioxidants as vitamin C (ascorbic acid), butylated hydroxytoluene supplements. The researchers recruited a total of 12 cross-country skiers, endurance runners and triathletes at the Australian Institute of Sport, an Olympic training center. Half took 1,000 international units of vitamin E and 1,000 milligrams of vitamin C daily; the rest received sugar pills. After four weeks, each group switched to the other's supplements.
After vitamin supplementation, "there was a 25 percent reduction in tissue oxidation," as evidenced by levels of two enzymes assayed in the blood, Gillam says. This suggests not only that the membranes in muscle -- and probably the heart -- are less damaged by oxidant oxidant /ox·i·dant/ (ok´si-dant) the electron acceptor in an oxidation-reduction (redox) reaction.
See oxidizer. stress during normal training if supplements are taken, but also that red blood cells Red blood cells
Cells that carry hemoglobin (the molecule that transports oxygen) and help remove wastes from tissues throughout the body.
Mentioned in: Bone Marrow Transplantation
red blood cells sustain less damage, he says. Gillam's team also found signs that vitamins E and C altered concentrations of two hormones in the blood. A reduction in the normal ratio of testosterone to cortisol cortisol (kôr`tĭsôl') or hydrocortisone, steroid hormone that in humans is the major circulating hormone of the cortex, or outer layer, of the adrenal gland. serves as a marker of "overtraining overtraining
training horses or dogs too hard so that they lose spirit.
overtraining Sports medicine A general term for any practice of, or training for, a particular sport which is in excess of that necessary to participate in the sport , which syndrome," a condition that can provoke a range of symptoms and diminish athletic performance. After supplementation, testosterone-cortisone ratios in these athletes actually increased.
"We don't have hard scientific evidence yet that we can improve [athletic] performance with antioxidant supplementation, but there's lots of evidence . . . that supplementation protects against damage [during training and competition]," concludes antioxidant specialist Lester Packer of the University of California, Berkeley The University of California, Berkeley is a public research university located in Berkeley, California, United States. Commonly referred to as UC Berkeley, Berkeley and Cal , who organized a meeting session on this topic.