The Alberta Physical Activity and Breast Cancer Prevention Trial: quality of life outcomes.

OBJECTIVE: Interventions for disease prevention should also be evaluated for quality of life (QoL) effects. Few exercise trials have examined QoL in the context of primary disease prevention. Here, we report the QoL outcomes from the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) Trial. METHODS: The ALPHA trial was a randomized controlled trial in Calgary and Edmonton, Canada between May 2003 and July 2007 that compared an exercise intervention to a sedentary lifestyle among 320 sedentary, postmenopausal women. The exercise group was asked to perform moderate-to-vigorous intensity aerobic exercise 45 min/day, 5 days/week for 1 year. QoL was assessed by the short form-36 health survey. RESULTS: Compared to the control group, the exercise group maintained significantly better physical functioning (p<0.001), general health (p<0.001), vitality (p=0.002), and bodily pain (p=0.020) by 4-5 points which exceeds the 3.0 minimally important difference for these scales. Changes in body composition partially mediated the intervention effects. Antidepressant use and the presence of comorbidities moderated some intervention effects. CONCLUSIONS: A 1-year moderate-to-vigorous aerobic exercise program prevents declines in the physical aspects of QoL in postmenopausal women. Exercise may have a potentially important advantage for breast cancer prevention compared to other lifestyle or biomedical interventions.