The health benefits of working out with weights
by: Jeannine Stein | from: Los Angeles Times | February 13, 2011
Strength training has strong-armed its way beyond the realm of bodybuilding. A growing body of research shows that working out with weights has health benefits beyond simply bulking up one’s muscles and strengthening bones. Studies are finding that more lean muscle mass may allow kidney dialysis patients to live longer, give older people better cognitive function, reduce depression, boost good cholesterol, lessen the swelling and discomfort of lymphedema after breast cancer and help lower the risk of diabetes.
- “Muscle is our largest metabolically active organ, and that’s the backdrop that people usually forget,” said Kent Adams, director of the exercise physiology lab at Cal State Monterey Bay. Strengthening the muscles “has a ripple effect throughout the body on things like metabolic syndrome and obesity.”
Historically, strength training was limited to athletes, but in the last 20 years, its popularity has spread to the general public, said Jeffrey Potteiger, an exercise physiologist at Grand Valley State University in Grand Rapids, Mich., and a fellow of the American College of Sports Medicine. “One can argue that if you don’t do some resistance training through your lifespan, you’re missing out on some benefits, especially as you get older or battle weight gain,” he said.
When we hit middle age, muscle mass gradually diminishes by up to about 1% a year in a process called sarcopenia. Women also are in danger of losing bone mass as they age, especially after the onset of menopause. Some studies have shown that moderate to intense strength training not only builds skeletal muscle but increases bone density as well.
Strength training often takes a back seat to cardiovascular training, but it can benefit the heart in ways that its more popular cousin can’t. During cardio exercise, the heart loads up with blood and pumps it out to the rest of the body: As a result, Potteiger said, “the heart gets better and more efficient at pumping.”
But during resistance training, muscles generate more force than they do during endurance exercises, and the heart is no exception, Potteiger said. During a strength workout, the heart’s muscle tissue contracts forcefully to push the blood out. Like all muscles, stress causes small tears in the muscle fibers. When the body repairs those tears, muscles grow. The result is a stronger heart, not just one that’s more efficient at pumping.
Another big advantage of working out with weights is improving glucose metabolism, which can reduce the risk of diabetes. Strength training boosts the number of proteins that take glucose out of the blood and transport it into the skeletal muscle, giving the muscles more energy and lowering overall blood-glucose levels.
“If you have uncontrolled glucose levels,” Potteiger said, “that can lead to kidney damage, damage to the circulatory system and loss of eyesight.”