Effects of active commuting and leisure-time exercise on fat loss in women and men with overweight and obesity: a randomized controlled trial.

Abstract

Aerobic exercise is recommended for weight management but energy balance is often less negative than predicted from exercise energy expenditure (ExEE). To examine effects of active commuting and leisure-time exercise on fat loss in women and men with overweight and obesity. We randomized 130 younger, physically inactive women and men with overweight and obesity (body mass index: 25-35 kg m^-²) to 6 months of habitual lifestyle (control; CON, n=18), active commuting (BIKE, n=35) or leisure-time exercise of moderate (MOD, 50% VO₂peak reserve, n=39) or vigorous intensity (VIG, 70% VO₂peak reserve, n=38). The primary outcome was change in fat mass measured by dual-energy X-ray absorptiometry, which was analyzed intention-to-treat. Accumulated energy balance was calculated based on changes in body composition, and ExEE was calculated based on heart rate monitoring during exercise. Testing at 3 and 6 months was completed by 95 and 90 participants, respectively. Fat mass was reduced after 3 and 6 months in BIKE (3 months: -3.6 (-5.5; -1.7) kg (mean (95% CI)); 6 months: -4.2 (-6.6; -1.9) kg; both: P<0.001), MOD (3 months: -2.2 (-3.9; -0.4) kg; 6 months: -2.6 (-4.8; -0.5) kg, both: P<0.02) and VIG (3 months: -3.4 (-5.2; -1.7) kg; 6 months: -4.5 (-6.6; -2.3) kg; both: P<0.001) compared with CON. Furthermore, fat loss was greater in VIG compared with MOD (6 months: -1.8 (-3.6; -0.1) kg, P=0.043). Based on the ExEE and the accumulated energy balance MOD compensated for the ExEE (77 (48; 106) %) but not BIKE (38 (-18; 95) %) and VIG (21 (-14; 55) %). A meaningful fat loss was obtained by 6 months of active commuting and leisure-time exercise, but fat loss was greater with vigorous compared with moderate intensity exercise. Active commuting is an alternative to leisure-time exercise in the management of overweight and obesity. The trial was registered at clinicaltrials.gov as NCT01962259 (main trial) and NCT01973686 (energy metabolism sub-study).