Walk more to halt aging - study

Regular exercise, including walking, significantly reduces the chance that a frail older person will become physically disabled, according to a new study. The study finds that a moderate-intensity physical activity program reduces major mobility disability among older adults at risk for disability. "Preserving the ability to walk 400 meters [about a quarter mile] … is central to maintaining a high quality of life and independence in the community," wrote the authors. "Four hundred meters is once around the track, or from the parking lot to the store, or two or three blocks around your neighborhood," said co-principal investigator Jack Guralnik, Ph.D., a professor of epidemiology and public health at the University of Maryland School of Medicine, via the release. "It's an important distance in maintaining an independent life." The results, published on Tuesday in the journal JAMA, reinforce the necessity of frequent physical activity for our aging parents, grandparents and, of course, ourselves, NYT reports. Among the elderly, reduced mobility is common and contributes to their risk for illness, hospitalization, and even death. Despite an intuitive belief that physical activity would prevent loss of mobility, no clinical trials have ever investigated whether activity truly prevents or delays mobility disability. For this reason, Dr. Marco Pahor of the University of Florida, Gainesville, and his colleagues designed the Lifestyle Interventions and Independence for Elders (LIFE) study. "For the first time, we have directly shown that exercise can effectively lessen or prevent the development of physical disability in a population of extremely vulnerable elderly people," said Dr. Marco Pahor. Countless epidemiological studies have found a strong correlation between physical activity in advanced age and a longer, healthier life. But such studies can’t prove that exercise improves older people’s health, only that healthy older people exercise. Other small-scale, randomized experiments have persuasively established a causal link between exercise and healthy aging. But the scope of these experiments has generally been narrow, showing, for instance, that older people can improve their muscle strength with weight training or their endurance capacity with walking. So, for this latest study, the Lifestyle Interventions and Independence for Elders, or LIFE, trial, scientists at eight universities and research centers around the country began recruiting volunteers in 2010, using an unusual set of selection criteria. Unlike many exercise studies, which tend to be filled with people in relatively robust health who can easily exercise, this trial used volunteers who were sedentary and infirm, and on the cusp of frailty. Ultimately, t he team of researchers selected 1,635 participants at eight urban and suburban academic centers in Gainesville and Jacksonville, Fla.; Chicago, Ill.; Baton Rouge, La.; Pittsburgh, Pa.; Stanford, Calif.; Boston, Mass.; Winston-Salem, N.C.; and New Haven, Conn. The average age of the chosen participants was 78.9 years, more than half (about 67 percent) were women, and nearly 18 percent were African-American. Then the men and women were randomly assigned to either an exercise or an education group. Those in the education assignment were asked to visit the research center once a month or so to learn about nutrition, health care and other topics related to aging. The exercise group received information about aging but also started a program of walking and light, lower-body weight training with ankle weights, going to the research center twice a week for supervised group walks on a track, with the walks growing progressively longer. They were also asked to complete three or four more exercise sessions at home, aiming for a total of 150 minutes of walking and about three 10-minute sessions of weight-training exercises each week. Every six months, researchers checked the physical functioning of all of the volunteers, with particular attention to whether they could still walk 400 meters by themselves. The experiment continued for an average of 2.6 years, which is far longer than most exercise studies. Most of the volunteers "tolerated the exercise program very well," Dr. Pahor said, but the results did raise some flags. More volunteers in the exercise group wound up hospitalized during the study than did the participants in the education group, possibly because their vital signs were checked far more often, the researchers say. The exercise regimen may also have "unmasked" underlying medical conditions, Dr. Pahor said, although he does not feel that the exercise itself led to hospital stays. What did the researchers discover? Nearly half (45 percent) of the participants in the physical activity group experienced a considerable benefit by working their program. Meanwhile, major mobility disability (loss of ability to walk 400 meters) was experienced by 30.1 percent (246 participants) in the physical activity group and 35.5 percent (290 participants) in the health education group; and persistent mobility disability was experienced by 14.7 percent of participants in the physical activity group and 19.8 percent of participants in the health education group. "The LIFE study showed that, over 2.6 years of follow-up, the physical activity intervention compared with the health education intervention significantly reduced major mobility disability," wrote the authors in their conclusion. "At first glance, those results are underwhelming," said Dr. Lewis Lipsitz, a professor of medicine at Harvard Medical School and director of the Institute for Aging Research at Hebrew SeniorLife in Boston, who was not involved with the study. "But then you have to look at the control group, which wasn’t really a control group at all." That’s because in many cases the participants in the education group began to exercise, study data shows, although they were not asked to do so. "It wouldn’t have been ethical" to keep them from exercise, Dr. Lipsitz continued. But if the scientists in the LIFE study "had been able to use a control group of completely sedentary older people with poor eating habits, the differences between the groups would be much more pronounced," he said. Over all, Dr. Lipsitz said, "it’s an important study because it focuses on an important outcome, which is the prevention of physical disability." In the coming months, Dr. Pahor and his colleagues plan to mine their database of results for additional followup, including a cost-benefit analysis. He and his colleagues hope that the study prompts Medicare to begin covering the costs of group exercise programs for older people. Dr. Pahor cautioned that the LIFE study is not meant to prompt elderly people to begin solo, unsupervised exercise. "Medical supervision is important," he said. Talk with your doctor and try to find an exercise group, he said, adding, "The social aspect is important." Source: The Voice of Russia

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