WINSTON-SALEM, N.C. – June 27, 2017 – Moderate-intensity exercise can help even extremely obese older
adults improve their ability to perform common daily activities and remain independent,
according to researchers at Wake Forest Baptist Medical Center.
Findings from the National Institutes of Health-funded study are
published in the July issue of the journal Obesity.
In the United States, obesity affects nearly 13 million adults age
65 and older. Both overall obesity and abdominal obesity are strongly
associated with the development of major mobility disability
(MMD), the inability to walk a quarter of a mile,
according to the study’s lead author, Stephen Kritchevsky, Ph.D., director of
the Sticht Center for Healthy Aging and Alzheimer's Prevention at Wake Forest Baptist.
Previous data on older populations had suggested that obesity may
lessen the beneficial effects of physical activity on mobility. However, this research,
which analyzed data from the multicenter Lifestyle Interventions and
Independence for Elders (LIFE) study, showed that a structured physical
activity program reduced the risk of MMD even in older adults with extreme
“The inability to walk a quarter of a mile is a proxy for common
daily activities, such as the inability to walk a block around the neighborhood
or to walk several street blocks to go to a store,” Kritchevsky said. “Having a
major mobility disorder can really affect the quality of life and independence
for older people, but we showed that moderate exercise was a safe and effective
way to reduce that risk even in severely obese people.”
The LIFE study was a large clinical trial that enrolled 1,635
sedentary men and women age 70 to 89. The participants were randomized to a
moderate intensity physical activity program or a health education program to
test if the physical activity program would reduce the rate of MMD compared to
the education program. Major mobility disability was defined as the inability
to walk 400 meters (about a quarter of a mile) without sitting and without help
from another person or a walker, Kritchevsky said.
Participants were divided into four groups according to body mass
index (BMI) – a measure of body fat based on height and weight – and waist
circumference: non-obese with BMI less than 30; non-obese with high waist circumference
of more than 40 inches for men and 34 inches for women; class 1 obese with BMI
between 30 and 35; and class 2 obese with BMI of 35 or higher.
The physical activity program focused on walking, strength,
balance and flexibility training. The goal for participants was to be able to
walk at moderate intensity for 30 minutes and perform 10 minutes of
lower-extremity strength training with ankle weights and 10 minutes of balance
training in a single session. Participants attended two center-based training
sessions per week and performed at-home activities three to four times per week
during the two-year study.
The health education program involved in-person group workshops
focused on aging-relevant topics such as nutrition, safety and legal/financial
issues. Sessions included lectures and interactive discussions and five to 10
minutes of upper body stretching exercises.
While there was no significant difference between obesity category
and intervention effect, those in the class 2 obesity group showed the greatest
benefit from the physical activity program, reducing their risk of MDD by 31
percent, Kritchevsky said.
The LIFE study was the first to demonstrate that moderate
intensity physical activity can significantly reduce the risk of MMD in
sedentary older adults.
Co-authors are: Laura Lovato, M.S., and Elizabeth P. Handing,
Ph.D., Wake Forest Baptist; Steven Blair, P.E.D., University of South Carolina;
Anda Botoseneau, M.D., University of Michigan; Jack M. Guralnik, M.D.,
University of Maryland School of Medicine; Christine Liu, M.D. Boston
University School of Medicine; Abby King, Ph.D., Stanford University School of
Medicine; Anthony P. Marsh, Ph.D., and W. Jack Rejeski, Ph.D., Wake Forest
University; Marco Pahor, M.D., and Todd Manini, Ph.D., University of Florida
College of Medicine; and Bonnie Spring, Ph.D., Northwestern University Feinberg
School of Medicine.
The LIFE study was funded by a National Institutes of
Health/National Institute on Aging Cooperative Agreement UO1 AG22376 and a
supplement from the National Heart, Lung and Blood Institute
3U01AG022376-05A2S, and sponsored in part by the Intramural Research Program,
National Institute on Aging. The research was partially supported by the Claude
D. Pepper Older Americans Independence Centers at the University of Florida (1
P30 AG028740), Wake Forest University (1 P30 AG21332), Tufts University
(1P30AG031679), University of Pittsburgh (P30 AG024827) and Yale University
(P30AG021342) and the NIH/NCRR CTSA at Stanford University (UL1 RR025744),
Tufts University is also supported by the Boston Rehabilitation Outcomes Center