Strategies to change body composition in older adults: do type of exercise and dose distribution matter?

Background: This study aims to analyze changes in sedentary elderlies' body composition, comparing the impact of two dose distributions: continuous (60 min/session) vs. accumulated (30 min/session in the morning and 30 min/session in the afternoon), on two types of physical exercise programs (multicomponent-training [MCT] vs. walking interval-training [WIT]).

Methods: Forty-six sedentary overweight elderly (71.3±4.3 years) were evaluated by bioimpedance with a pre-post 2x2 factorial design. Participants were distributed in four homogeneous groups, considering gait and health parameters.

Results: The overall sample showed significant improvements in fat mass (% and kg) and fat-free mass (kg) following 15 weeks of training. There was a main effect of "type of exercise" and a moderating effect of "dose distribution" reflected in the interaction of both factors. Bonferroni analyses of the type*dose interaction revealed significant improvements in all groups, except for MCT-accumulated, on both body composition compartments.

Conclusions: Starting exercise training, properly periodized and supervised by physical-education trainers, improves body composition of sedentary elderlies regardless of the type of exercise. Accumulated strategies were beneficial only when applied to WIT. Although MCT training improves body composition with only 2 days/week, WIT-accumulated could be a key element in the design of weight control policies looking for breaking sedentary behaviors.