Fig. 2: Schematic representation of the study design.

Measurements were conducted prior to intervention (control phase) and within the final two weeks of a 12-week supervised aerobic exercise intervention (intervention phase). A Total daily energy expenditure and body composition were measured using the isotope dilution method (doubly labeled water). B Volumes of highly metabolic organs (brain, liver, and kidney) were assessed using magnetic resonance imaging. C Whole room indirect calorimetry was used to assess: D resting metabolic rate, E diet-induced thermogenesis, F sleeping metabolic rate, and G exercise economy. H Exercise energy expenditure and cardiovascular fitness were monitored using ametabolic cart, I daily physical activity was monitored using a tri-axial accelerometer, and J exercise training was evaluated using an optical heart rate sensor. Written informed consent for publication of identifiable images was obtained from all participants shown. BMI body mass index, kcal kilocalories, wk week.