Psychological changes associated with 16-wk moderate and low intensity exercise training programs, two of which possessed a cognitive component, were evaluated. Subjects were healthy, sedentary adults, 69 women (mean age = 54.8 +/- 8.3 yr) and 66 men (mean age = 50.6 +/- 8.0 yr). Participants were randomly assigned to a control group (C), moderate intensity walking group (MW), low intensity walking group (LW), low intensity walking plus relaxation response group (LWR), or mindful exercise (ME) group-a Tai Chi type program. Women in the ME group experienced reductions in mood disturbance (tension, P < 0.01; depression, P < 0.05; anger, P < 0.008; confusion, P < 0.02; and total mood disturbance, P < 0.006) and an improvement in general mood (P < 0.04). Women in the MW group noted greater satisfaction with physical attributes (body cathexis, P < 0.03), and men in MW reported increased positive affect (P < 0.006). No other differences were observed between groups on measures of mood, self-esteem, personality, or life satisfaction. Equivocal support is provided for the hypothesis that exercise plus cognitive strategy training programs are more effective than exercise programs lacking a structured cognitive component in promoting psychological benefits.