Sept. 17, 2001 -- A landmark study, three decades in the making, offers some of the best scientific evidence yet that it's never too late to reap dramatic benefits from exercise. Researchers found that six months of endurance training reversed a 30-year decline in cardiovascular fitness among a group of middle-aged men who were first studied in their 20s.
Kasmer Laszlo was one of five young men who, in the name of science, stayed in bed for three weeks in 1966. The men showed a dramatic decline in cardiovascular fitness following the inactivity, and the Dallas Bed Rest and Training Study was instrumental in educating doctors about the value of exercise.
Thirty years later, the men, all in their early 50s, were brought back together for six months of endurance training. Only two of the five men exercised regularly before the follow-up study began, but by the end of the training period all were getting four-and-a-half hours of aerobic exercise a week.
After the six-month training period, all five men were back to the fitness level they had 30 years earlier. The findings are reported in this week's issue of Circulation.
"I certainly didn't expect that regular exercise could make that big of a difference at my age," Laszlo, now 56 and an engineer in Dallas, tells WebMD. "I just thought I was getting older and there wasn't much room for improvement. The study has definitely encouraged me to stay active."
The follow-up study shows that even modest levels of exercise can produce dramatic improvements in fitness, study author Darren K. McGuire, MD, of the University of Texas Southwestern Medical Center at Dallas, tells WebMD. But he says another very important finding is that it does not take long to lose the benefits of exercise if you don't stay active.
"Remarkably, this study shows that 20 days of bed rest caused the cardiovascular fitness of these men who were in their 20s to decline worse than 30 years of aging," he says. "There is a lot of bang for the buck when you start exercising, and it is realized quickly. But the corollary to that is that as quickly as it is realized it can be lost."
Heart specialist Lynn Smaha, MD, a past president of the American Heart Association, says he is not surprised by the study findings. The original study, he added, helped change the thinking about the recovery of heart patients.
"In days gone by, people who had [heart attacks] were put on bed rest for six weeks," he tells WebMD. "These days, I have patients who have had heart surgery up and walking a mile a day in the hospital within a week. That sets the stage, and they recover much faster than if they get no exercise."
Smaha, who runs four miles a day, says lack of exercise is probably the second leading contributor to heart disease, behind smoking. Current American Heart Association guidelines call for 30 to 45 minutes of exercise three to five times a week, but new guidelines to be released within the next few weeks are expected to recommend some aerobic exercise every day.
"Maintaining an exercise program throughout life results in a better quality of life," Smaha says. "And this study shows that it is never too late to start."
Study participant Laszlo agrees. With three children who are athletes, including a 27-year-old son who competes in Iron Man competitions, Laszlo says he has plenty of motivation to keep active.
"I still work out, but I have to admit I think walking is boring," he says. "I do sports because it's fun. But it doesn't matter what you do as long as you keep your heart rate up a bit."