The effects of short- vs. long-bout exercise on mood, VO2max, and percent body fat

BACKGROUND: To compare the ACSM-CDC physical activity accumulation recommendation to the traditional recommendation, for impact on mood and physiological markers of fitness. METHODS: Randomized controlled trial with sedentary male (n = 21) and female (n = 19) subjects assigned to walk either long bouts (LB; 30 min/day), short bouts (SB; 3 x 10 min/day), or a nonexercise control (CTL) group for 8 weeks. Pre- and post-measures were collected for V02max and percent body fat. Pre-, mid-, and post-measures were collected for the Profile of Mood States (POMS). RESULTS: VO2max increased in the SB group (+7.2%) and LB (+6.7%; P < or = 0.05). Percent body fat decreased in the LB group (-6.7%; P < or = 0.05). Total mood disturbance (TMD) decreased in the LB and SB groups (P < or = 0.05); only the LB group showed reductions compared to the CTL group (P < or = 0.05). Tension-anxiety and vigor-activity were altered in the LB group compared to the other two groups (P < or = 0.05). Reductions in percent body fat correlated with TMD (r = 0.38; P < or = 0.05) and Tension-anxiety reduction (r = 0.40; P < or = 0.05). CONCLUSIONS: LB and SB walking produced similar and significant improvements in VO2max LB walking was more effective at reducing percent body fat, tension-anxiety and total mood disturbance, and increasing vigor compared to the control group.