A Little Fitness May Go a Long Way

Physical activity in small amounts may increase life span, compared to no exercise

(RxWiki News) Regular exercise may be one of the best ways to live a longer, healthier life. And new evidence suggests that even low levels of activity can make a difference.

A new study builds on past research, finding that the risk of dying may drop with even a minimal amount of exercise. Increases in exercise corresponded to increases in life span, the authors of this study found. However, the return on high levels of physical activity started to go down at a certain point.

Doctors have long known that exercise is good for you. It can improve heart, lung, musculoskeletal and mental health. It may even help fight diabetes. In 2012, the National Institutes of Health (NIH) issued a report indicating that people who got half the recommended amount of exercise added almost two years to their lives.

And patients shouldn't worry too much about the type of exercise they do, said Tenesha R. Chappell, MD, an internal medicine physician at Baylor Regional Medical Center at McKinney, Texas.

"Few data demonstrate superiority of 1 physical activity over another," Dr. Chappell told dailyRx News. "Select activity or sport that you enjoy to maximize likelihood of continued physical activity such as brisk walking, yard work, dancing, bicycling, jogging, or other leisure sport."

Hannah Arem, PhD, MHS, of the National Cancer Institute, led this study.

“Meeting the 2008 Physical Activity Guidelines for Americans minimum by either moderate- or vigorous-intensity activities was associated with nearly the maximum longevity benefit,” Dr. Arem and colleagues wrote.

These researchers studied data on more than 661,000 men and women. The patients' average age was 62 at the start of this study. Over a median follow-up of 14 years, Dr. Arem and team recorded nearly 117,000 deaths.

Study patients provided data on their exercise habits, including the average weekly time spent walking, jogging/running, swimming, playing tennis/racquetball, bicycling, doing aerobics and dancing.

Dr. Arem and team observed that “any level of activity was associated with a significantly lower risk of mortality.”

They noted a 20 percent lower risk of dying among those performing less than the recommended minimum amount of activity — compared to those had no leisure-time physical activity.

The recommended minimum is at least two hours and 30 minutes a week of moderate-intensity exercise, such as brisk walking, according to the 2008 Physical Activity Guidelines for Americans from the US Office of Disease Prevention and Health Promotion. This amount of exercise translates to 7.5 metabolic-equivalent (MET) hours per week. METs are a measure of the oxygen the body uses during exercise.

"While a general weekly goal of at least 150 minutes of moderate to 75 minutes of vigorous intensity exercise is ideal, even modest increases in exercise are associated with improved health benefits and decrease in risk of premature death," Dr. Chappell said.

Patients in the current study who exercised enough to meet the minimum requirement or up to double that amount had a 31 percent lower risk of dying than those who were inactive, Dr. Arem and team found.

This risk level dropped even further for those who got two to three times the minimum amount of exercise. Their risk of dying was 37 percent lower than those reporting no exercise.

For those who exercised at levels three to 10 times above the minimum, the risk of dying was 39 percent lower than that of the inactive patients, Dr. Arem and colleagues found.

Patients who performed 10 or more times above the minimum still had a longevity benefit, but the payoff began to decrease at this point. This group had a 31 percent lower mortality risk than the inactive patients.

“The findings provide important evidence to inactive individuals by showing that modest amounts of activity provide substantial benefit for postponing mortality while reassuring very active individuals of no exercise-associated increase in mortality risk,” Dr. Arem and team wrote.

In an editorial about this study, Todd M. Manini, PhD, of the University of Florida in Gainesville, added that getting people to exercise regularly remains a challenge.

“Essentially, the major barriers continue to be motivation, time, access to facilities or equipment, energy, having a workout partner and [belief in oneself],” Dr. Manini wrote.

The study and editorial were published online April 6 in JAMA Internal Medicine.

This research was funded in part by the NIH. Dr. Arem and team disclosed no conflicts of interest.

Review Date: 
April 5, 2015