Physical activity has clear health benefits but there remains uncertainty about how it affects health care costs.
To examine how physical activity is associated with changes in health expenditure for a national sample age 54 to 69 y, and estimate how this association varies across people with different chronic diseases and health behaviors.
Data were from the Health and Retirement Study, a national longitudinal survey of late middle age Americans.
Correcting for baseline differences in active and inactive groups, physical activity was associated with reduced health care costs of about 7% over 2 y (or $483 annually).
Regular physical activity in late middle age may lower health expenditure over time, and the effect is likely to be more pronounced for the obese, smokers, and individuals with some baseline health problems. While substantially large for the health care system, our estimates are much smaller than health-unadjusted comparisons or cross-sectional effects.