By Pat Anson, Editor

Older adults who are physically active are better able to block pain signals and may have a lower risk of developing chronic pain, according to a small study published in the journal Pain.

Researchers at Indiana University-Purdue University Indianapolis performed a series of experiments on 51 healthy adults, aged 60 to 77, who wore monitoring devices for one week to measure their physical activity. Participants were given heat and pressure tests to measure their “pain modulation” – how the central nervous system interprets and perceives pain.

Both tests found that pain modulation was significantly related to physical activity. Older adults with more frequent moderate-to-vigorous physical activity had lower pain scores, while those who were sedentary were less able to block pain signals. Even light physical activity appeared to lower pain perception.

"This study provides the first objective evidence suggesting that physical activity behavior is related to the functioning of the endogenous pain modulatory systems in older adults," wrote lead author Kelly Naugle, PhD, of the Center for Physical Activity in Wellness and Prevention, Indiana University–Purdue University Indianapolis.

"Our data suggest that low levels of sedentary behavior and greater light physical activity may be critical in maintaining effective endogenous pain inhibitory function in older adults."

Previous studies have shown that pain modulation is poor in patients with chronic pain conditions such as arthritis, back pain and fibromyalgia.

Aging is associated with chronic low-grade inflammation and oxidative stress, which could make the peripheral and central nervous systems more sensitive to pain. Older adults are also more likely to be sedentary and less physically active, which would make them more vulnerable to chronic pain.

Recent studies have documented the benefits of exercise for older adults. Chair yoga reduced pain and improved the quality of life in older adults with osteoarthritis. Another study found that just 45 minutes of moderate exercise a week improved function and reduced pain levels.