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Vol. LXVI, No. 4
February 14, 2014
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Get Moving
Exercise Your Way to a Longer, Healthier Life, Forum Speakers Urge

NIA’s Dr. Chhanda Dutta

NIA’s Dr. Chhanda Dutta

If people were aware of the litany of health benefits that arise from regular exercise, even the busiest among us would make it a priority. Keeping fit confers major health benefits—that message resonated at a recent Staff Training in Extramural Programs (STEP) forum, “Move: Physical Activity Benefits Everyone,” held in NLM’s Lister Hill Auditorium.

Research shows that regular exercise helps lower the risk of early death, heart disease, stroke, high blood pressure and type 2 diabetes. In seniors, increased physical activity canimprove bone density, balance, sleep quality and may improve cognitive function.

The American College of Sports Medicine (ACSM) first established clinical guidelines on exercise in 1975. The recommendation was to exercise at 70-90 percent capacity 3- 5 days per week. By 1991, while the frequency remained the same, the ACSM modified the intensity level to a range of 40-85 percent.

“There was a growing awareness among the scientific community as well as the clinical community that the intensity of exercise probably didn’t have to be as great as initially thought in order to provide important health benefits,” said Dr. Russell Pate, professor in the department of exercise science in the Arnold School of Public Health, University of South Carolina.

The HHS Physical Activity Guidelines recommend adults get 2½ hours per week of moderate intensity aerobics or half that amount in vigorous activity. In addition, it is recommended that adults do muscle-strengthening acti vities at least 2 days per week.

The STEP panel included (from l) Dr. Jerry Phelps, Dr. Greg Cartee, Dutta and Dr. Russell Pate.

The STEP panel included (from l) Dr. Jerry Phelps, Dr. Greg Cartee, Dutta and Dr. Russell Pate.

Physical activity has an impact on many tissues and organs, said Dr. Greg Cartee, associate dean for research at the school of kinesiology, University of Michigan. He defined physical activity as “any movement produced by the contraction of skeletal muscle that increases energy expenditure above basal levels.”

Effects that occur during, or just after, a single exercise session are acute responses, such as increased heart rate or some longer-lasting effects such as increased muscle glucose uptake, said Cartee, who is also director of the Muscle Biology Laboratory at Michigan. Many more changes occur at the cellular level, as various enzymes and proteins work to regulate metabolism and the effects of exercise.

The effects of exercise are cumulative, said Cartee. Chronic adaptations are the continuing effects of regular, repeated bouts of acute exercise. But the positive outcomes will reverse in time if people don’t remain regularly physically active.

Pate has finished in the top 10 at the Boston Marathon, but concedes that exercise need not be intensive to provide benefit.

Pate has finished in the top 10 at the Boston Marathon, but concedes that exercise need not be intensive to provide benefit.

Photos: Ernie Branson

“Many of [the benefits] are lost in a matter of days or weeks,” he said. These positive adaptations over time will increase endurance, with the extent of the benefits being related to the “exercise dose,” which is determined by the duration, frequency and intensity of the workout.

Dr. Jerry Phelps, a program analyst with NIEHS, knows a thing or two about endurance. Once an avid runner, he suffered an injury that inspired him to get a bicycle in 2003. He became a devoted cyclist. Phelps began by joining a randonneurs club, a group of noncompetitive, long-distance cyclists.

“I set some intermediate goals,” he recounted. “And I did my first single-day 100-mile ride in 2003.” He has twice completed the 750-mile Paris-Brest-Paris, the oldest continuously offered bike ride in the world. To build up to this event, he completed smaller qualifying rides, 100-400 miles each. Over the last decade, he has participated in more than 200 different bike events and cycled more than 50,000 miles.

While not everyone exercises at that intensity, Pate, who has twice placed in the top 10 of Boston Marathon finishers, and Phelps both started with modest goals. Even if you’ve let your exercise routine lapse for some time, it’s never too late to begin again. “Having been fit at one point, and staying fit, substantially reduces your risk of mortality,” said Dr. Chhanda Dutta, chief of the Clinical Gerontology Branch, NIA.

Dr. Phelps Dr. Greg Cartee
Phelps (l) biked his way to fitness and Cartee warned that letting up on exercise means letting up on the benefits of fitness.

Regular physical activity is equally important for older adults, many of whom suffer symptoms of chronic disease and might not know where to start. In 2012, NIA launched Go4Life, a national fitness campaign to help older adults incorporate exercise into their daily lives, including motivational tips for the more sedentary folks. The campaign recommends older adults exercise a minimum of 300 minutes per week, to develop strength, balance, flexibility and endurance.

Another concern with the aging population is sarcopenia, the loss of muscle mass. Dutta said data shows sarcopenia can begin in people as young as their mid-40s; the decrease in muscle mass only progresses from there.

“No one is ever too old to exercise,” said Dutta, “and you can always reap some kind of benefit by engaging in exercise.”


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