Dynamic mechanisms of exercise to improve body satisfaction: Perceived or actual fat loss?

Abstract

We examined the dynamic mechanisms of aerobic training (AT) and strength training (ST) to improve body satisfaction. Sixty-six participants were randomised to either the AT or ST condition and completed an 8-week intervention. Participants completed 3 weekly, 30-minute sessions of moderate intensity AT (65-75% VO₂ max) or ST (65-75% 1-RM). The energy consumption of each session was approximately equivalent under both conditions. Body satisfaction, body composition, perceived fitness and exercise self-efficacy were measured at baseline and biweekly during the intervention. Exercise improved individuals' body satisfaction (p < .05). When the energy expenditures of AT and ST were equal, there was no difference in body satisfaction improvement. There were dynamic mechanisms underlying the effects of exercise on body satisfaction. Specifically, perceived fitness influenced body satisfaction improvements during the early stages of the exercise program, while changes in body composition influenced body satisfaction toward the end of the exercise program. There were sex differences in the mechanisms underlying body satisfaction. For women, perceived fat was more important in the early intervention period; for men, actual body fat was more valuable in the late intervention period. An effective strategy to improve body satisfaction is to initially target perceived fitness before focusing on changing body composition.

Keywords: Body composition; Body image; Perceived fitness; Self-efficacy.