REASON TO MOVE

Study finds exercise before age 65 can help renew the heart

There’s hope for all the couch potatoes out there: If you’re middle-aged and out of shape, a new study finds you can “reverse” the effects of your sedentary lifestyle on your heart with a couple of years of exercise — as long as you start before age 65.

A sedentary lifestyle is linked to all sorts of negative outcomes, from weight gain and hypertension to heart problems and diabetes.

Heart failure rates are expected to increase 46 percent by 2030 and affect up to 8 million people, according to the American Heart Association.

The small, 53-person study from researchers at the Institute for Exercise and Environmental Medicine UT Southwestern, a collaboration between UT Southwestern Medical Center and Texas Health Presbyterian Hospital Dallas, appears in the American Heart Association’s journal Circulation.

‘A prescription for life’

No matter how long a person has been inactive, just two years of regular exercise can help the heart bounce back and regain the plasticity and elasticity of a younger, healthier person, said Dr. Benjamin Levine, director of the institute and professor of internal medicine at UT Southwestern.

“With the right amount and kind of exercise a person can prevent the effects of a sedentary lifestyle,” Levine said. “I recommend people commit themselves to four or five days a week of exercise. It’s a prescription for life.”

To reap the most benefit, the exercise regimen should begin by late middle age, between 55 and 65, when the heart apparently retains some plasticity and ability to remodel itself, Levine said.

The workout

The exercise regimen used in the study was specific and included exercising four to five times a week, generally in 30-minute sessions, plus warm-up and cooldown. Similar results were not seen in people who exercised two or three times a week, Levine said.

Participants started at a moderate level of training and built up intensity. One weekly session included a high-intensity 30-minute workout, such as aerobic interval sessions in which heart rate topped 95 percent of peak rate for four minutes, with three minutes of recovery, repeated four times.

Each interval session was followed by a relatively low-intensity recovery session. One day’s session lasted an hour and was of moderate intensity, such as playing tennis or walking. Other sessions included moderate activity where participants broke a sweat, and strength training using weight or exercise machines.

At the end of the twoyear study, those who completed the exercise program were not only fitter, they showed an 18 percent improvement in maximum oxygen intake during exercise.

Additionally, they saw a more than 25 percent improvement in compliance, or elasticity, of the left ventricular muscle of the heart, Levine said. He compared the change in the heart to a stretchy, new rubber band versus one that has gotten stiff sitting in a drawer.

What it means

Sedentary aging increases the risk of heart failure because it can lead to a stiffening of the muscle in the heart’s left ventricle, the chamber that pumps oxygen-rich blood out to the body, Levine said.

“When the muscle stiffens, you get high pressure and the heart chamber doesn’t fill as well with blood.

In its most severe form, blood can back up into the lungs. That’s when heart failure develops,” Levine said.

Regular exercise should become a part of a person’s “personal hygiene,” Levine said. “Just like brushing your teeth and taking a shower.”