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Run,
Don't Walk to Stave Off Heart Death
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.
Reference
Source 89
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