Effect of Resistance Training on Skeletal Muscle Mass and Brown Adipose Tissue Activity

Brown adipose tissue (BAT) may be effective in preventing obesity and type II diabetes; however, there are no established reports on exercise-induced changes in BAT. This study focused on BAT variability in women undergoing resistance training (RT) interventions twice weekly for 10 weeks in cold environments. Fifteen participants were recruited: seven were randomly assigned to an RT group and eight to a control (CT) group. To evaluate BAT density (BAT-d), total haemoglobin concentration was measured using near-infrared time-resolved spectroscopy before and after the intervention. There was no significant difference in BAT-d between the CT and RT groups after the intervention (p = 0.921). There was a positive correlation between Δskeletal muscle (SM) mass and ΔBAT-d in the RT group (r = 0.615, p = 0.142). Supraclavicular region-specific thermogenesis (SST) had a significant positive correlation with BAT-d in the RT group (r = 0.889, p = 0.007). These results suggest that RT may be involved in BAT variability, owing to the trend of increased BAT-d with increased ΔSM mass and SST, although there was no significant increase in BAT-d after the RT intervention.