Long-term physical activity patterns and health-related quality of life in US women

Background: Despite studies showing that physically active individuals report higher quality-of-life scores, few data exist on the impact of changing physical activity levels on subsequent changes in quality of life. Methods: Subjects were 63,152 women in the Nurses' Health Study aged 40 to 67 years in 1986. Women reported their physical activity on questionnaires in 1986, 1988, 1992, 1994, and 1996, and were grouped according to quartile of change in activity from 1986 to 1996. Women also reported seven health-related quality-of-life dimensions in 1996 and 2000 using the Medical Outcomes Study Short-Form 36 Health Status Survey. The main outcome measures were scores for each of these seven dimensions in 1996, as well as changes in each of these dimensions from 1996 to 2000. Data were analyzed in 2006. Results: In age and baseline activity adjusted analyses, compared to women whose physical activity was relatively stable from 1986 to 1996, women who saw any increase in physical activity levels had higher quality-of-life scores in 1996. Among women with a clear increase in physical activity, the increase in quality-of-life scores ranged from 2.23 (95% confidence intervals [CI] = 1.94-2.52) for mental health to 8.23 (95% CI = 7.49-8.97) for role limitations due to physical problems. Increasing physical activity also was associated with greater increases in quality-of-life scores from 1996 to 2000 compared to women whose physical activity level was stable. The strongest association was for role limitations due to physical problems, where women with a clear increase in physical activity had a significant improvement (1.81, 95% CI = 1.09-2.53) in the outcome. Conclusions: Long-term physical activity patterns are an important determinant of health-related quality of life.