“Previous studies have shown that physical activity in midlife can help prevent a variety of chronic diseases,” said lead investigator Kushang Patel, Ph.D., of the National Institute on Aging in Bethesda, Md. “Our study shows that greater physical activity in your 30s, 40s and 50s has beneficial effects well into the future by helping us maintain our ability to walk and function at older ages.”
The study was reported in the September issue of the American Journal of Preventive Medicine.
The investigators gathered and analyzed data from a population-based survey conducted from 1998 to 2000, of 1155 adults age 65 years and older. Slightly more women participated than men. Average age was 74.8 years, peaking at an impressive 102 years. Average BMI was 27.5., which is considered overweight.
The participants were asked to recall physical activity levels in midlife, before undergoing mobility testing and a medical examination.
The investigators used two objective measures of present mobility as a function of past physical activity, the Short Physical Performance Battery (SPPB) and the ability to walk 400 meters (or 437 yards).
The most prevalent category of physical activity in midlife — divided into ages 20 to 40 and 40 to 60 — was “moderate” for both men and women, although the proportion of men reporting more intense physical activity levels in midlife was higher than among women.
As expected, physical activity in the past year was lower than levels reported for midlife.
The researchers found that people with higher levels of physical activity in midlife were significantly more likely to achieve a higher SPPB score than those who had been less physically active.
In addition, failure to complete the 400-meter walk test was significantly less likely among physically active men and very active men when compared to their less-active peers.
“Specifically, higher levels of physical activity were associated with better lower-extremity function (SPPB) in both genders, but the ability to walk 400 meters was associated only with past physical activity in men and not in women,” the authors found.
The midlife/old-age activity associations held after adjustment for demographic factors, medical conditions and physiologic impairments.
"It has long been suggested that regular physical activity plays an important role in protecting an individual against the disabling process,” said Wojtek Chodzko-Zajko, Ph.D., a professor of kinesiology and community health at the University of Illinois at Urbana-Champaign. “However, relatively little is known about the time course of physical activity’s impact on mobility and subsequent disablement….The study underscores the importance of current public health recommendations.”
Adults are urged to achieve a minimum of 30 minutes of moderate-to-vigorous physical activity of most days of the week, Chodzko-Zajko said.
Patel KV, et al. Midlife physical activity and mobility in older age: the InCHIANTI study. Am J Prev Med 31(4), 2006.