Promising to exercise for better health is usually the hardest New Year's resolution to keep. But a growing body of research shows that it should be one of the easiest.
Numerous studies now show that you don't always have to break a sweat to reap the most significant health benefits of exercise. While national health guidelines often suggest 30 to 60 minutes a day of exercise, it appears to take far less effort than that to make a dramatic improvement in your health. The biggest health benefits come from just a small increase in activity: Five hours of housework a week, a nine-minute walk a day, or four hours of weekend golf all translate into dramatic reductions in risk for heart attacks and other health problems.
Most people think they need to take a daily jog or hit the gym several times a week to boost health. That's because for years the medical community has preached the need for vigorous aerobic activity and athletic fitness. Those are laudable goals with clear benefits, including improved muscle tone, energy levels and psychological well-being. But they also are tough goals, so people often fail and end up doing nothing.
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Now many doctors are trying to undo the wrong impression caused by the aerobics movement. They are trying to redefine how much exercise is really enough and encourage patients to think about achieving "health fitness" rather than athletic fitness.
"I regret preaching the doctrine of aerobics as I did for so many years," says Harvey B. Simon, the Harvard Medical School professor whose 1987 book "The Athlete Within" urged readers to expend at least 2,000 calories a week exercising — that's about three to six hours a week of aerobic effort, depending on the activity. He now believes it takes only about half that amount to improve health. "We need a new way to think about exercise," he says.
So what's the magic number? In June 2001, researchers reviewed 44 exercise studies and found that most of the benefits of exercise kick in with the first 1,000 calories of increased activity each week, which reduced the risk of dying during the various study periods by 20 percent to 30 percent, according to the Journal of Medical Science and Exercise.
To burn 1,000 calories a week or about 145 calories a day, most people need to increase their daily activity only slightly. A 180-pound person could burn off about 100 calories during 20 minutes of housework. Add in a 10-minute walk (50 calories) or taking the stairs four times a day (100 calories) and you've exceeded your daily goal. Search the Web for an exercise calculator like the one at www.caloriecontrol.org/ exercalc.html online.
Other studies have supported the notion that a little activity goes a long way. This month, the medical journal Diabetes Care showed that moderate exercise added nearly 2 1/2 years to life expectancy for patients, compared with those who were sedentary. A 2004 report by Swedish researchers showed that older adults who exercised only once a week were 40 percent less likely to die during the 12-year study period than those who did nothing.
Much of what we know about moderate exercise and health comes from observational studies following groups of people for long periods of time. But the Cooper Institute — whose founder Kenneth Cooper coined the term "aerobics" — has just finished a five-year study of 460 postmenopausal women who were assigned to 225, 150 or just 75 minutes of exercise a week — that's as little as 15 minutes five times a week. The results of the trial aren't yet available, but the study is part of a new push by scientists to determine what "dose" of exercise offers the biggest gains in health. And there's a growing belief that it's less than the standard 30-minutes-a-day recommendation.
"All the evidence shows it doesn't take that much," says Tim Church, medical director for the Cooper Institute in Dallas.
The problem is convincing patients that a little extra effort really does go a long way. "The average person still thinks you have to train for a marathon," Dr. Church says.
Baby steps
Here's a look at the benefits of very little exercise demonstrated in various medical studies.
Activity
55 flights of stairs a week
One hour of gardening a week
Walking one hour a week
Regular, demanding household cleaning
Exercising 30 minutes just six days a month
Benefit
33 percent lower death rate
66 percent lower risk of sudden cardiac death
51 percent lower risk of coronary artery disease
Lowered heart-attack risk by 54 percent in men and 84 percent in women
43 percent lower mortality rate