Physical activity associated with healthier aging: Links between exercise and cognitive function, bone density and overall health

Exercise has previously been linked to beneficial effects on arthritis, falls and fractures, heart disease, lung disease, cancer, diabetes and obesity, write Jeff Williamson, M.D., M.H.S., and Marco Pahor, M.D., of University of Florida, Gainesville, in a commentary. All of these conditions threaten older adults' ability to function independently and handle tasks of daily living.

"Regular physical activity has also been associated with greater longevity as well as reduced risk of physical disability and dependence, the most important health outcome, even more than death, for most older people," they continue. Four new studies published in this issue of the Archives -- outlined below -- "move the scientific enterprise in this area further along the path toward the goal of understanding the full range of important aging-related outcomes for which exercise has a clinically relevant impact."

Midlife Exercise Associated With Better Health in Later Years

Among women who survive to age 70 or older, those who regularly participated in physical activity during middle age appear more likely to be in better overall health. Qi Sun, M.D., Sc.D., of the Harvard School of Public Health, Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues analyzed data from 13,535 participants in the Nurses' Health Study.

The women reported their physical activity levels in 1986, at an average age of 60. Among those who had survived to age 70 or older as of 1995 to 2001, those who had higher levels of physical activity at the beginning of the study were less likely to have chronic diseases, heart surgery or any physical, cognitive or mental impairments.

"Since the American population is aging rapidly and nearly a quarter of Americans do not engage in any leisure-time activity, our findings appear to support federal guidelines regarding physical activity to promote health among older people and further emphasize the potential of activity to enhance overall health and well-being with aging," the authors conclude. "The notion that physical activity can promote successful survival rather than simply extend the lifespan may provide particularly strong motivation for initiating activity."

Resistance Training Programs Appear to Improve Some Cognitive Skills in Older Women

One year of once- or twice-weekly resistance training appears to improve attention and conflict resolution skills among older women. Teresa Liu-Ambrose, Ph.D., P.T., of Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada, and colleagues studied 155 women age 65 to 75. Participants were randomly assigned to participate in resistance training once (54 women) or twice (52 women) weekly, whereas 49 women in a control group participated in twice-weekly balance and tone training.

After one year, women in both resistance training groups significantly improved their scores on tests of selective attention (maintaining mental focus) and conflict resolution. The program simultaneously improved muscular function in the women.

"This has important clinical implications because cognitive impairment is a major health problem that currently lacks a clearly effective pharmaceutical therapy and because resistance training is not widely adopted by seniors," the authors write. "The doses of resistance training we used in this study fall within those recommended by the 2008 Physical Activity Guidelines for seniors."

Physical Activity May Be Associated With Reduced Cognitive Impairment In Elderly Population

Moderate or high physical activity appears to be associated with a lower the risk of developing cognitive impairment in older adults after a two-year period. Thorleif Etgen, M.D., of Technische Universität München, Munich, and Klinikum Traunstein, Germany, and colleagues examined physical activity and cognitive function in 3,903 participants (older than 55) from southern Bavaria, Germany between 2001 and 2003.

At the beginning of the study, 418 participants (10.7 percent) had cognitive impairment. After two years, 207 (5.9 percent) of the remaining 3,485 unimpaired study participants developed cognitive impairment. "The incidence of new cognitive impairment among participants with no, moderate and high activity at baseline was 13.9 percent, 6.7 percent and 5.1 percent, respectively," the authors write.

"Future large randomized controlled intervention trials assessing the quantity (e.g., no activity vs. moderate vs. high activity) and quality (aerobic exercise or any kind type of physical exercise, like balance and strength training or even integrated physical activities like dancing or games) of physical activity that is required to prevent or delay a decline in cognitive function are recommended," they conclude.

Exercise Program Associated With Denser Bones, Lower Fall Risk in Older Women

Women age 65 or older assigned to an exercise program for 18 months appeared to have denser bones and a reduced risk of falls, but not a reduced cardiovascular disease risk, compared with women in a control group. Wolfgang Kemmler, Ph.D., and colleagues at Freidrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany, studied a total of 246 older women. Half of the women exercised four days per week with special emphasis on intensity while the other half participated in a wellness program that focused on well-being.

Among the 227 women who completed the study, the 115 who exercised had higher bone density in their spine and hip, and also had a 66 percent reduced rate of falls. Fractures due to falls were twice as common in the controls vs. the exercise group (12 vs. six). However, the 10-year risk of cardiovascular disease -- assessed using the Framingham Risk Calculator, which incorporates factors such as cholesterol level, blood pressure and presence of diabetes -- decreased in both groups and did not differ between the two.

"Because this training regimen can be easily adopted by other institutions and health care providers, a broad implementation of this program is feasible," the authors conclude.