Monday, March 4, 2013

Physical Activity and Health

by Gregory J. Colman, Dhaval M. Dave - #18858 (HE)


While the link between physical activity and health has been studied,
there are several limitations that persist in this literature
relating to external and internal validity of the estimates,
potential measurement error in self-reported weight and risk factors,
failure to account for physical activity beyond exercise, and failure
to separate the effects of exercise from other forms of physical
activity. This study addresses these gaps and assesses plausibly
causal effects of recreational exercise and other physical activity
(including work-related activity) on the risk factors for heart
disease, utilizing a population-based longitudinal dataset that
contains objective information on key risk factors.

There are four key patterns of results that emerge:

First, the lagged effect of physical activity is almost
always larger than the current effect. This suggests that current
risk factors, not only obesity but also high blood pressure and heart
rate, take years to develop, which underscores the importance of
consistent physical activity to ward off heart disease.

Second, in general physical activity reduces risk factors for heart
disease even after controlling, to some extent, for unobservable
confounding influences.

Third, not only recreational but work-related physical activity
appears to protect against heart disease.

Finally, there is evidence of a dose-response relationship
such that higher levels of recreational exercise and other physical
activity have a greater protective effect.

Declines in high levels of recreational exercise and other physical
activity can potentially account for between 12-30% of the increase
in obesity, hypertension, diabetes, and heart disease observed over
the sample period.

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