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 × 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 ≤ 0.05). Percent body fat decreased in the LB group (−6.7%; P ≤ 0.05). Total mood disturbance (TMD) decreased in the LB and SB groups (P ≤ 0.05); only the LB group showed reductions compared to the CTL group (P ≤ 0.05). Tension–anxiety and vigor–activity were altered in the LB group compared to the other two groups (P ≤ 0.05). Reductions in percent body fat correlated with TMD (r = 0.38; P ≤ 0.05) and Tension–anxiety reduction (r = 0.40; P ≤ 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.