Effects of 12 weeks of resistance exercise on 24-hour subjective appetite measured under highly controlled conditions inside a metabolic chamber in older men

Rationale: While ageing is associated with reduced appetite1, an increase in fat-free mass (FFM) with age has been associated with increased appetite2. This study investigated the effects of 12 weeks of resistance exercise (RE) on FFM and 24-hour subjective appetite in older men.

Methods: In a pooled-group analysis from a previous 12-week, 4-arm, randomised, double-blind, placebo-controlled trial3, 33 older men (age: 67±1yrs; BMI: 25.4±0.4 kg/m2) were pooled to either RE (2x/week; n=17) or no exercise (NE; n=16). At baseline and 12 weeks, FFM was measured by bioelectrical impedance analysis and participants resided in metabolic chambers4 during which subjective appetite (hunger, satiety, fullness, and desire to eat) was measured 9 times over 24 hours via visual analogue scales (VAS)5. The area under the curve (AUC) for appetite VAS ratings were calculated over the 24-hour measurement period.

Results: FFM significantly increased in the RE group compared to the NE group (1.0±0.3kg vs. 0.1±0.3kg, p=0.04). A significant increase over time was observed for 24-hour AUC hunger in the RE group only (p=0.03); however, no significant differences in 24-hour AUC hunger (p=0.35), satiety (p=0.58), fullness (p=0.41), or desire to eat (p=0.21) occurred between groups. Controlled for age and intervention group, no significant correlations were observed between ΔFFM and ΔVAS outcomes.

Conclusion: Despite an increase in FFM, 12 weeks of RE had no greater effect compared to NE on subjective appetite measured over 24-hours under highly controlled conditions in older men.