A Newly Discovered Benefit of Strength Training
Older adults who followed strength-training guidelines had lower odds of dying than those who weren’t as physically active, according to researchers at Penn State College of Medicine, Penn State Health Milton S. Hershey Medical Center and Columbia University.
The study is the first to demonstrate the association in a large, nationally representative sample over an extended time period, particularly in an older population.
Many studies have previously found that older adults who are physically active have better quality of life and a lower risk of mortality. Regular exercise is associated with prevention of early death, cardiovascular disease, diabetes and some cancers.
But although the health rewards of physical activity and aerobic exercise are well established, less data have been collected on strength training.
One reason for this lack of data could be that strength-training guidelines are newer than recommendations for aerobic activity. Although the American College of Sports Medicine first issued aerobic exercise guidelines decades ago, it was not until 2007 that the organization and the American Heart Association released a joint guideline recommending that all adults strength train at least twice a week.
“This doesn’t mean that strength training wasn’t a part of what people had been doing for a long time as exercise, but it wasn’t until recently that it was solidified in this way as a recommendation,” said Jennifer L. Kraschnewski, assistant professor of medicine and public health sciences, Penn State College of Medicine.
Over the past decade, researchers have begun to demonstrate benefits of strength training for strength, muscle mass and physical function, as well as for improvements in chronic conditions such as diabetes, osteoporosis, low back pain and obesity. Small studies have observed that greater amounts of muscle strength are associated with lower risk of death.
To look at the mortality effects on older adults who meet strength-training guidelines, Kraschnewski examined data from the 1997-2001 National Health Interview Survey (NHIS) linked to death certificate data through 2011. Researchers published their results in Preventive Medicine.
The NHIS collects overall health, disease and disability data of the U.S. population from a nationally representative sampling of all 50 states and the District of Columbia. The 1997-2001 survey included more than 30,000 adults age 65 and older.
During the survey period, more than 9 percent of older adults reported strength training at least twice a week.
“That’s only a small fraction of the population, but it’s actually higher than we had anticipated,” Kraschnewski said.
The researchers followed the respondents for 15 years through death certificate data from the National Center for Health Statistics National Death Index. About a third of respondents had died by 2011.