A study from cardiologists at UT Southwestern Medical Center and Texas Health Resources has found that exercise can reverse damage to the heart in a sedentary adult – if he or she does enough exercise in time.
Senior study author Dr. Benjamin Levine, director of the Institute for Exercise and Environmental Medicine and professor of internal medicine at UT Southwestern, describes the damage of a sedentary lifestyle.
“The heart shrinks and stiffens. The muscle mass goes down and then the heart doesn’t stretch as well. And when blood flows into it, the pressure ends up going relative high."
Levine said that can eventually lead to heart failure. The study found an exercise regimen performed four to five days a week and begun by late middle age can help the heart remodel itself. Waiting until after age 65 produces no results.
The researchers compared athletes, who were active over their lifetime, to a group of healthy seniors (over 65, with an average age of 70) with no chronic medical problems.
That’s where they learned that the heart shrinks and stiffens as a person ages, even with healthy sedentary living, Levine said. The athletes, on the other hand, had hearts that were "indistinguishable from healthy 30 year-olds," he said.
The sedentary subjects trained for a year, but even so, regular exercise at that age could not reverse the structure of the heart and blood vessels, Levine said.
The regimen included exercising four to five times a week, generally in 30-minute sessions, plus a warmup and cool-down.
- One of the weekly sessions included a high-intensity 30-minute workout, such as aerobic interval sessions, in which the heart rate tops 95 percent of peak rate for four minutes, with 3 minutes of recovery, repeated four times — a so-called "4x4".
- Each interval session was followed by a recovery session performed at relatively low intensity.
- One day’s session lasted an hour and was of moderate intensity. (As a “prescription for life,” Levine said this longer session could be a fun activity such as tennis, aerobic dancing, walking or biking.)
- One or two other sessions were performed each week at a moderate intensity, meaning the participant would break a sweat, be a little short of breath, but still be able to carry on a conversation – known as the “talk test.”
- One or two weekly strength training sessions using weights or exercise machines were included on a separate day, or after an endurance session.