May 28, 2014
Daily 20-Minute Walks Could Help Seniors Stave Off Major Disability
April Flowers for redOrbit.com - Your Universe Online
Moderate exercise is the key to good health in nearly every situation. That is especially true for older adults, according to countless commercials and public health sources.
LIFE is a collaboration between Yale University, the University of Florida, Southern Connecticut State University, Northwestern University, Pennington Biomedical Research Center, Stanford University, Tufts University, the University of Pittsburg, and Wake Forest University. A total of eight field centers participated in the study, the results of which were published in a recent issue of the Journal of the American Medical Association (JAMA) and presented at the American College of Sports Medicine Conference.
Mobility is the ability to walk without assistance. For older adults, mobility becomes the key to independent living and quality of life. Many older adults suffer from a decrease in mobility, which is a risk factor for illness, hospitalization, disability and death. The LIFE study found that moderate physical activity, such as that 20-minute daily walk, helped seniors maintain their ability to walk at a rate of 18 percent higher than those who did not exercise.
"The very purpose of the study is to provide definitive evidence that physical activity can truly improve the independence of older adults," said principal investigator Marco Pahor, PhD, director of the UF's Institute on Aging.
Moderate exercise also helped to prevent long-term mobility loss, as well. The study found a 28 percent reduction in people permanently losing the ability to walk easily.
"The fact that we had an even bigger impact on persistent disability is very good," said Co-principal investigator Jack Guralnik, PhD, a professor of epidemiology and public health at the University of Maryland School of Medicine, who also holds a faculty position at UF. "It implies that a greater percentage of the adults who had physical activity intervention recovered when they did develop mobility disability."
For the purposes of the study, the researchers defined mobility as the ability to walk 1,300 feet, or approximately one-quarter of a mile. The research team said that although a quarter mile sounds arbitrary, for older adults it is significant.
"Four hundred meters is once around the track, or from the parking lot to the store, or two or three blocks around your neighborhood," Guralnik said. "It's an important distance in maintaining an independent life."
The research team recruited 1,635 men and women ages 70 to 89. The participants were mostly sedentary, with the ability to walk 1,300 feet in 15 minutes, but were in danger of losing that ability. Pahor said that patients with low physical performance are not often the subject of large studies because it can be a predictor of early death, and higher hospitalization and institutionalization rates. This is the largest randomized controlled trial ever conducted on physical activity and health education in older adults.
"These are people who are patients we see every day. This is why this study is so important: It includes a population that is typically understudied," Pahor said.
The participants were followed for an average of 2.6 years between February 2010 and December 2013. The cohort was separated into two study groups. One group of 818 patients walked 150 minutes per week and did strength, flexibility and balance training. This group visited field centers twice a week for monitoring. The remaining 817 patients attended health education classes and performed stretching exercises.
The participants were assessed by staff members every six months. They were evaluated for their ability to walk, their body weight, blood pressure and pulse rate, along with other measurements. The participants were assigned to their group randomly, and the staff was not informed which patient was in which group.
One surprising result was found: in the physically active group, the number of hospitalizations was slightly higher than in the education group. The increase was not statistically significant, however. The team suggests this could be due to the more frequent contact with research staff of the physical activity group, allowing more opportunities to report hospitalizations. Underlying heart trouble and other health problems could also have been triggered by the activity, which warrants further study, according to Pahor.
"It's quite a vulnerable and high-risk population," Pahor said. "Both age and poor health were factors. We selected people who had low physical performance, which is a strong predictor for future morbidity, hospitalization, institutionalization and mortality."
Before the launch of the main LIFE trial, Wendy Kohrt, PhD, professor of medicine in the division of geriatric medicine at the University of Colorado, helped review the scientific merit of the study.
"As an exercise scientist, I believe this type of research is absolutely critical to establish scientific evidence on which to make recommendations for how lifestyle can beneficially influence health status," said Kohrt.
"There is a general belief among the public and the scientific and medical communities that we know exercise is good for you, so why do we need to do more research in this area? However, we still do not know whether certain types or doses of exercise are better than others, particularly for specific health conditions or diseases. The LIFE trial demonstrated that a modest increase in physical activity has the potential to help older adults maintain functional independence."
A great deal of data remains to be analyzed from the study, including the effects of physical activity on the emotional health of the participants. The team plans to continue their research to determine how physical activity impacted the participants' physiological, social and biological factors.
"We want to change how people live," said the director of the Yale field center, Thomas Gill, MD, the Humana Foundation Professor of Geriatric Medicine, who chaired the measurement committee, which was responsible for determining the main study outcomes. "Maintaining independence for older adults is both a public health and a clinical priority, and modifying lifestyle is an important approach to maintaining independence."
Gill added, "Years from now, LIFE will be considered a landmark study, one that has informed policies to keep older persons independent in the community."