Run, Don't Walk to Stave Off Heart Death: UK Study

Tuesday, April 15

LONDON (Reuters Health) - A brisk half-hour walk five days a week might make you healthier, but may not be enough to avoid a premature death from heart disease, British researchers reported on Tuesday.

Current UK and U.S. heart guidelines recommend 30 minutes of moderately intense physical activity five days a week, but a study of nearly 2,000 middle-aged men suggests that only more-vigorous exercise protects against an untimely end from cardiovascular disease.

Dr. John Yarnell from Queen's University Belfast, Northern Ireland, and colleagues studied 1,975 Welsh men aged 45 to 59, none of whom had signs of heart disease at the beginning of the study.

They followed the men for 11 years and correlated their leisure-time physical activity with deaths from cardiovascular conditions.

The researchers graded exercise according to intensity. Light activities included walking, bowling or sailing; moderate activities included golf and dancing; and vigorous activities included climbing stairs, swimming and jogging.

During the study, 252 men died. More than 75 percent of these were attributable to heart disease and stroke, and the remainder to cancer.

Men with the lowest leisure-time exercise levels were more likely to die during the study, the researchers found.

The heaviest levels of physical activity were associated with the lowest rates of death from all causes and heart disease. But moderate and light levels of regular exercise had no consistent impact on death rates.

"Vigorous physical activity, such as climbing stairs, hiking, jogging, swimming, tennis, badminton, squash and heavy digging, may independently prevent premature death, principally from cardiovascular disease and coronary heart disease in middle aged men who have no evidence of pre-existing coronary heart disease," the researchers write in the journal Heart.

Closer analysis showed that it was the intensity of exercise, rather than the number of calories burned, that seemed to be the crucial factor.

The few men who regularly engaged in the highest levels of heavy exercise, expending more than 54 calories a day in this way, were 47 percent less likely to die early and 62 percent less likely to die of heart disease. Those 54 calories equate to just nine minutes of jogging or doubles tennis, or seven minutes of climbing stairs.

But men who engaged in the highest levels of light to moderate exercise, expending an average 343 calories a day -- which is equivalent to more than 90 minutes of walking or an hour of ballroom dancing -- were not protected from the risk of an early death.

Belinda Linden from the British Heart Foundation, which partly funded the study, said that current guidelines have been developed through a consensus of national and international research over time.

"Whilst this study adds to our understanding of how levels of physical activity affect an individual's risk of heart disease in the long term, it is just one study," she said in a statement.

"While we recognize that vigorous activity will provide maximum cardiac protection and promote physical fitness, there is evidence that 'five times 30 minutes' moderate-intensity activity still appears to provide health benefits."

"There is still not enough evidence to suggest that the current messages are not appropriate."

SOURCE: Heart 2003;89:502-506.

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