|
Run,
Don't Walk to Stave Off Heart Death
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 report.
Current 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.
Article Source: Reuters Health
Article Author: N/A
Net Reference 89
|
