Effect of exercise on in vitro immune function: a 12-month randomized, controlled trial among postmenopausal women

published April 10, 2008; doi:10.1152/japplphysiol.01349.2007.— Cross-sectional studies suggest that moderate physical activity is associated with enhanced resting immune function; however, few randomized controlled trials have investigated this link. We investi-gated the effect of 12-mo aerobic exercise, relative to stretching control, on in vitro immune function in a randomized, controlled trial of 115 postmenopausal, overweight, or obese sedentary women, aged 50–75 yr. The exercise goal was 45 min/day, 5 days/wk. Control women participated in 1 day/wk stretching classes. Immune markers (natural killer cell cytotoxicity, T-lymphocyte proliferation, immune cell counts and phenotypes, and serum immunoglobulins) were as-sessed at baseline, 3 mo, and 12 mo under strict blood-draw criteria. General estimation equations evaluated intervention effects at 3 and 12 mo, controlling for baseline. Of the 115 women who began the trial, blood samples were available from 109 at 3 mo (95%) and 10