Study: Moderate exercise not enough to ward off early heart death
Tuesday, April 15th 2003, 12:00 am
News On 6
LONDON (AP) _ A half-hour brisk walk every day may make you feel better, but it is not enough to ward off premature death from heart trouble, new research suggests.
A study published this week in Heart, a British medical journal, found that only vigorous exercise _ such as jogging, hiking, climbing stairs, racket sports and swimming _ seems to help lower the risk of early death from heart disease. Other research has shown moderate exercise helps.
Official government recommendations in the United States and elsewhere say 30 minutes of moderate activity every day, such as brisk walking, is sufficient for heart health. A major World Health Organization consensus report published last month reached the same conclusion.
However, the latest study, conducted by scientists at Queen's University in Belfast, Northern Ireland, found that activities considered to provide mild exercise _ such as walking, bowling and sailing _ as well as pursuits of moderate intensity _ such as golfing, dancing and brisk walking _ did not lower the risk of early death among 2,000 British men followed for a decade.
``It's very compelling. It does kind of fly in the face of what we have been trying to tell people, and I think it will create a big stir,'' said Dr. Ron Sha, medical director of the Duke University Diet and Fitness Center in Durham, N.C.
Sha was not involved in the study.
Previous research has yielded conflicting results, dividing experts between a group that believes moderate exercise is enough and a smaller group convinced that vigorous exercise is needed before any heart benefit can occur.
``This is one report. It's important to have this information, but it's not sufficient for us to now scrap our recommendations, which rest on a huge amount of evidence,'' said Steven Blair, president of the Cooper Institute, a Dallas-based research organization that focuses on exercise.
Blair's own studies have concluded the heart benefits from moderate exercise.
The Belfast study involved 1,975 men who had no evidence of heart diseases and were between the ages of 49 and 64 when they entered the study. They each filled out an exercise questionnaire that estimated how many calories they burned each day through exercise in their spare time.
Types of exercise were classed as light, moderate or vigorous, according to how many calories the activity burned over a fixed period of time. About 30 percent of the men reported no vigorous exercise at all, and those who did exercise intensely did not do it very often.
After about 10 years, 252, or 13 percent, of the men had died, mostly from heart or blood vessel diseases.
One drawback of the study, the scientists acknowledged, is that the men only were questioned about their exercise habits one time at the start of the study, so there is no way to know whether the men changed their habits over the 10 years the study was conducted.
Only vigorous exercise was linked with a reduction in the risk of death from heart disease or any other cause within the 10 years of the study. The more heavy exercise the men did, the less their chances of dying during the study.
Those who did the most exercise were 40 percent less likely to die than those who did the least, the researchers found.
The results were adjusted for the exercise the men did at work, but that did not change its conclusions, the scientists said.
Studies that compare different intensities and patterns of exercise, but keep the number of calories burned equal, likely will provide stronger insight into the question of exactly what is required for heart health, Blair said.
He said the superiority of the vigorous exercise might simply come down to the fact that it burns more calories than moderate exercise.