Weight Training - Protecting
You Against Free Radical Damage

Aerobic exercise, including running, biking and walking, can strengthen the heart and improve cardiovascular health in old age. Now, study results suggest that another type of exercise--weightlifting--may also protect the heart.

According to findings presented recently at the annual meeting of the American College of Sports Medicine in Indianapolis, Indiana, lifting weights--even light ones--can protect against free radial damage. Free radicals are natural by-products of metabolism that have been implicated in the aging process and in a number of chronic illnesses such as heart disease and cancer.

The findings, said lead author Dr. Kevin Vincent of the University of Florida at Gainesville, suggest that elderly people and those who cannot lift heavy loads can still derive significant health benefits from weightlifting.

"You're never too old to start lifting weights," Vincent told Reuters Health.

"We think this will open up the options for prescribing exercise to seniors and other populations allowing them to use lighter loads that are less likely to cause injury but can still provide the same benefits," he noted in a statement.

The investigators found that healthy men and women aged 60 to 85 who performed a series of high- or low-intensity exercises with weights three times a week had less damage from free radicals after exertion, compared with a group of people who did not lift weights.

To measure free radical damage, the researchers looked at blood levels of lipid peroxides, compounds resulting from the oxidation of blood-borne fats that are thought to accumulate on the lining of arteries, contributing to atherosclerosis, or "hardening of the arteries."

After 6 months, the study participants were given an exercise test. The free radical damage increased 13% in the post-exercise period in the group that did not lift weights and decreased 2% in the low-intensity weightlifting group. However, free radical damage increased slightly--2%--in the high-intensity weightlifting group.

Vincent explained that exercise can cause free radical damage because it requires the body to use more oxygen. But exercise also enhances the body's natural defense system, thereby protecting against free radical damage, he said.

In other findings, people in the high-intensity group increased their bone mass, thereby reducing their risk of the bone-thinning disease osteoporosis, and lowered blood levels of homocysteine, a substance that can increase the risk of heart disease.

Both the high- and low-intensity groups showed improvements in aerobic fitness and increases in muscle strength and endurance after 6 months, Vincent's team observed.

"These findings suggest that resistance training in older adults may confer additional metabolic benefits...which may reduce the potential for chronic disease," said Barry Franklin, president of the American College of Sports Medicine, in a statement.