The following article comes from the U.S. News ebook, How to Live to 100, which is now available for purchase.
As 10,000 baby boomers a day turn 65, health officials are bracing themselves for a tsunami of chronic ills, from arthritis to osteoporosis. Yet a growing body of evidence shows that regular exercise can delay or prevent many age-related ailments, even among longtime couch potatoes.
"There's compelling data that older individuals participating in exercise programs show dramatic improvement in function and abilities," says Cedric Bryant, chief science officer for the American Council on Exercise in San Diego. In fact, experts suggest that many ills once attributed to normal aging are now being viewed as a result of chronic inactivity.
Despite this promising message, fewer than 5 percent of seniors follow the recommended guidelines for physical fitness (30 minutes of moderately intense exercise on most days). "Levels of activity in people 65 and older haven't budged in decades," says Miriam Nelson, director of the John Hancock Research Center on Physical Activity, Nutrition, and Obesity Prevention at Tufts University in Medford, Mass.
Even if they've never exercised, the middle-aged and older can still benefit by beginning now. Experts say sedentary people will actually fare better in percentage gains relative to active people, since they're starting from zero. "It doesn't matter how old you are," says Colin Milner, founder and CEO of the International Council on Active Aging in Vancouver, British Columbia. "It's never too late to start exercising."
Exercise may also benefit the body in ways we can't see: deep within our cells. A growing pile of evidence suggests it changes the way DNA behaves—for the better. For example, a single 20-minute workout appears to help tune-up DNA, allowing muscles to work better and more efficiently, according to a recent study published in Cell Metabolism. And encouragingly, a study published last year in PLoS Medicine found that people who are genetically predisposed to obesity can trump their DNA by exercising for about 30 minutes five days a week.
So, will exercise make you live longer? Hard to say. But those who exercise regularly will generally see a drop in their risk for many of the diseases and disabilities tied to aging. Consider:
Arthritis. If you suffer from the pain and stiffness of osteoarthritis, becoming more active may seem like the last thing you want to do. But increasingly, research suggests it could be one of the best strategies for feeling better, especially when it comes to sore knees—a common occurrence in older people. "Almost all studies show that exercise reduces pain and disability if it's done at a level that does not cause unusual pain during the workout, and no data show it's harmful," says N. John Bosomworth, clinical instructor in the Department of Family Practice at the University of British Columbia in Vancouver. Bosomworth says his 2009 peer-reviewed analysis of current research also found that the exercise benefit is roughly equivalent to the continuous use of nonsteroidal anti-inflammatory drugs, such as ibuprofen.
Dementia. "Exercise can keep your brain sharp," says Milner. Indeed, its effect on brain fitness is drawing the scrutiny of researchers. In a 2006 study by the Group Health Research Institute in Seattle, higher levels of physical activity were associated with a 30 to 40 percent reduction in the risk of dementia and Alzheimer's disease in people age 65 and up. "In our study, as little as 15 minutes a day, three times per week helped maintain the brain," says lead investigator Eric Larson, an internal medicine doctor and geriatric researcher.
Osteoporosis. Falls and broken bones often spell the difference between living independently and having to rely on assistance. Research indicates that exercise can prevent these setbacks by building stronger bones and lowering the risk of fractures. In a 2010 study, researchers compared women 65 and older who participated in an exercise regimen with peers who instead joined general wellness classes. Among the 227 women who completed the study, those who worked out showed significant increases in bone mineral density (BMD) in the spine and hips and a 66 percent reduction in the rate of falls. What's more, fractures due to falls were half as common in the exercise group as in the control group. In general, aerobics, weight-bearing activities (for example, walking, running, or stair climbing), and resistance exercises (which require the person to resist a particular force, like pulling against rubber tubing or lifting a dumbbell in a triceps curl) are all effective in increasing BMD in the spine.