By Katie Bell
Strength training twice weekly, as recommended by two national organizations, can help reduce all-cause mortality in older US adults, but fewer than 10% meet that recommendation, according to a study from Pennsylvania State University.
Motivating older adults to participate in strength training is especially challenging in those with functional limitations—including difficulty standing for two hours, stooping, bending, or kneeling—who may benefit the most, said lead author Jennifer Kraschnewski, MD, MPH, an associate professor of medicine and public health sciences at Penn State College of Medicine in Hershey, PA.
“Most clinicians believe exercise is a good thing for nearly every patient. Unfortunately, it is more difficult to convince patients who have challenges being active, such as those with functional limitations, to do so,” Kraschnewski said. “Strength training, for example, is excellent therapy following a fall. Unfortunately, people who have suffered a fall are less likely to be engaged in physical activity due to fear of falling.”
Kraschnewski’s team analyzed National Health Interview Survey (NHIS) data from 1997–2001, which were linked to death certificate data in the National Center for Health Statistics National Death Index, for more than 30,000 adults 65 years and older.
During the trial period, 9.6% of adults reported meeting the twice-weekly strength training guideline recommended by the American College of Sports Medicine (ACSM) and the American Heart Association (AHA), and 31.6% died. Participants who reported guideline-concordant strength training had a 46% lower likelihood of all-cause mortality than those who did not. Further, the association between strength training and mortality remained after adjustment for past medical history and health behaviors (which include level of physical activity). The findings were epublished in February by Preventive Medicine.
In a 2014 Preventive Medicine study, the same group analyzed NHIS data for 6763 older adults and found that those who complied with ACSM/AHA strength training guidelines were significantly less likely to have functional limitations than those who were noncompliant.
Nine functional limitations were studied, of which the most common were difficulty with standing for two hours, stooping, and bending or kneeling. Kraschnewski suggested that an inability to perform these actions can encourage sedentary behaviors.
Participants who met the strength training guidelines were less likely to have functional limitations. When each of the nine limitations were summed, 21.7% of participants with no limitations, 15.9% of participants with one to four limitations, and 9.8% of those with five to nine limitations met the guidelines.
The study authors concluded the potential for strength training to improve health is substantial, as those who have the most to gain from strength training participate the least.
“Often, the functional limitations can be improved with increased physical activity, although patients may need to start with physical therapy before advancing to a strength training program,” she said.
However, Kraschnewski noted that barriers to compliance other than functional limitations may also exist.
“Other factors may include a fear of being active, which can be overcome with support. Additional barriers include disinterest in going to a gym, particularly for older adults, suggesting innovative approaches to provide exercise programming are needed,” she said.
Wayne Westcott, PhD, instructor of exercise science at Quincy College in Quincy, MA, agreed that, as an older adult’s strength increases, he or she will be able to perform related physical activities with less musculoskeletal stress. Westcott also noted that, because strength training lends itself to customization, it may actually be particularly well suited for older adults with functional limitations.
“Unlike performing body-weight supporting activities, resistance exercise may be performed with external loads that may be adjusted to match the individual’s present level of muscular strength,” he said.
Kraschnewski JL, Sciamanna CN, Poger JM, et al. Is strength training associated with mortality benefits? A 15 year cohort study of US older adults. Prev Med 2016;87:121-127.
Kraschnewski JL, Sciamanna CN, Ciccolo JT, et al. Is exercise used as medicine? Association of meeting strength training guidelines and functional limitations among older US adults. Prev Med 2014;66:1-5.