Exercise to Protect Aging Bodies — and Brains

Read more: http://www.time.com/time/health/article/0,8599,1956619,00.html#ixzz0eQAcntI1



We all know that exercise is good for you. Staying physically active helps keep your heart healthy and your muscles strong, and in cancer patients it has even been shown to ward off relapse. Now a series of independently conducted studies on the effects of exercise in healthy older adults, published on Monday in the Archives of Internal Medicine, confirms that logging time at the gym not only helps maintain good health but may even prevent the onset of chronic diseases, such as heart disease, osteoarthritis and dementia.

In one surprising trial, researchers led by Dr. Teresa Liu-Ambrose at the University of British Columbia randomly assigned 155 aging women to three separate groups and directly compared the cognitive effects of two types of exercise: resistance training, done once or twice weekly, in which participants worked out with free weights and weight machines and did squats and lunges, versus toning and balance exercises, which participants did twice a week. (See pictures of a canine cognition lab.)

By the end of the yearlong study, the women who weight-trained saw an improvement in their performance on cognitive tests of memory and learning as well as in executive functions such as decision-making and conflict resolution — women who trained once a week improved their scores in executive functioning by 12.6% — while those who did balance and toning exercises showed no such improvement. The muscle-strengthening exercise also helped the volunteers, ages 65 to 75, boost their walking speed, a commonly used indicator of overall health status in the elderly, as faster pace has been linked with lower mortality. (See pictures of sassy women who love younger men.)

The Canadian researchers' findings were somewhat unexpected, given that previous studies on the issue have typically focused on aerobic exercise, which experts believe enhances cognitive function by promoting blood flow to the brain. Liu-Ambrose says her team speculated that anaerobic weight training would have a similar effect for other reasons. First, a resistance-training regimen requires a considerable amount of learning, especially for elderly people who may not be accustomed to the equipment. To learn how to use dumbbells, a leg press or a latissimus pull-down machine correctly, for example, the volunteers were required to focus on the task at hand, master new techniques and retain new information about proper and safe use of equipment. Previous studies have shown that such learning can help older adults maintain mental acuity. (See "The Year in Health 2009: From A to Z.")