For overweight baby boomers looking for ways to live longer and healthier lives, breaking a sweat might be more important than shedding pounds.
A study in today's Journal of the American Medical Association found that regardless of their weight, people of middle age who remain fit are less likely to die for any reason than their sedentary counterparts. Even obese people benefited from regular, moderate exercise, seeing significant reductions in their risk of heart attack, stroke and other illnesses, the study found.
"Fitness and fatness are two different things," said Dr. Steven N. Blair, a professor at the University of North Texas who was lead author of the paper. "You can be fat and be fit - and if you exercise, you are going to get some protection."
Other doctors agreed that the study highlights the importance of physical exercise for health but warned that Blair's results should not be interpreted as a license to pig out.
"Being extremely overweight seems to be uniformly associated with adverse outcomes," said Dr. Lawrence Cheskin, director of the Johns Hopkins Weight Management Center. "Even with exercise, being obese is a significant risk factor for dying."
Blair said the study was the first to rigorously explore the relative contributions of fitness level and weight to an older adult's risk of dying.
The researchers followed more than 2,600 men and women enrolled in the Aerobic Center Longitudinal Study. Participants' average age was 64, and they were examined between 1979 and 2001 at the Cooper Clinic in Dallas.
Doctors determined participants' fitness level by recording how long they could walk on a treadmill with their heart beating at 85 percent of its maximum rate for their age.
Their percentage of body fat was determined by measuring their body mass index (BMI), a widely used height to weight ratio.
People are considered overweight if their BMI is over 25 and obese if it is over 30. A person who is 5 feet 9 inches tall and weighs 203 pounds, for instance, has a BMI of 30 and is considered minimally obese. Experts typically consider a BMI over 35 as dangerously obese.
When they followed up after 12 years, the Texas researchers found that 450 of the study participants had died from a variety of causes. The vast majority - 75 percent - succumbed to cardiovascular disease or cancer.
