Background: Higher levels of leisure time physical activity (LTPA) are associated with reduced mortality. However it is unclear how changes in LTPA over time impact all-cause mortality in men and women.
Methods: From 1958 to 1996 for men (n=1316) and 1978 to 1996 for women (n=776), participants aged 19-90+ years from the Baltimore Longitudinal Study of Aging (Baltimore, MD) were assessed for LTPA at baseline and at approximately 2-year intervals over a mean follow-up of 21.2+/-9.4 years for men and 10.2+/-5.6 years for women. Death occurred in 538 men and 90 women. LTPA was derived from self-reports of time spent in 97 activities converted into MET-min per 24 h and was further grouped into high-, moderate- and low-intensity LTPA. The longitudinal data was analyzed using mixed effects models to determine the rate of change in LTPA at each assessment. Proportional hazard models were used to assess the associations between LTPA at baseline and rate of change in LTPA with all-cause mortality.
Results: In younger (<70 years) men, those who reported increases or negligible declines in total and high-intensity LTPA had lower all-cause mortality compared to those with greater declines in LTPA. In older (>or=70 years) men, the association between rate of change in high-intensity LTPA and mortality was similar to that seen in younger men. For women, longitudinal analyses showed neither rates of change in total, high-, moderate- nor low-intensity LTPA were predictive of mortality.
Conclusions: In this health-conscious population, greater longitudinal declines in total and high-intensity LTPA are independent predictors of all-cause mortality in men.