Sex-specific changes in appetite and energy intake in response to chronic resistance training in rats

Resistance training (RT) is widely prescribed for health, yet its effects on energy compensation and appetite regulation remain poorly defined, particularly across sexes. This study examined the effects of chronic RT on energy intake and appetite-regulating hormones in rats. Animals (n = 40) were assigned to female control, female RT, male control, or male RT and completed a 12-week ladder-based RT protocol. Energy intake was assessed longitudinally, and hormonal responses were measured during a resistance training exercise test (RTET). RT reduced total energy intake (p = 0.022) without altering energy intake relative to body weight. Males exhibited reduced body weight and energy intake, whereas females did not, despite greater relative training volume. Postexercise energy intake was elevated in RT groups (p = 0.029), indicating delayed compensatory feeding. Acyl-ghrelin increased following RTET (p < 0.001) and was higher in RT and females (p < 0.001). Leptin, insulin, GLP-1, and PYY were unchanged. These findings demonstrate sexually dimorphic energy compensation during RT, associated with ghrelin secretion rather than tonic appetite hormones. RT appears to shift compensation toward episodic, ghrelin-mediated pathways, with females exhibiting greater sensitivity. This identifies an endocrine framework for RT-induced energy compensation and emphasizes the need for sex-specific approaches to exercise prescription and energy balance regulation.