The impact of exercise intensity on whole body and adipose tissue metabolism during energy restriction in sedentary overweight men and postmenopausal women

Objective: To establish whether vigorous-intensity exercise offers additional adipose-related health benefits and metabolic improvements compared to energy-matched moderate-intensity exercise.Methods: Thirty-eight sedentary overweight men (n=24) and postmenopausal women (n=14) aged 52 ± 5 years (mean ± SD) were prescribed a 3-week energy deficit (29302 kJ·week-1) achieved by increased isocaloric moderate or vigorous-intensity exercise (+8372 kJ·week-1) and simultaneous restricted energy intake (-20930 kJ·week-1). Participants were randomly assigned to either an energy-matched vigorous (VIG; n=18) or moderate (MOD; n=20) intensity exercise group (five times per week at 70% or 50% maximal oxygen uptake, respectively). At baseline and follow-up, fasted blood samples and abdominal subcutaneous adipose tissue biopsies were obtained and oral glucose tolerance tests conducted.Results: Body mass was reduced similarly in both groups (Δ 2.4 ± 1.1 kg and Δ 2.4 ± 1.4 kg, respectively, P<0.05). Insulinaemic responses to a standard glucose load decreased similarly at follow-up relative to baseline in VIG (Δ 8.6 ± 15.4 nmol.120min.l-1) and MOD (Δ 5.4 ± 8.5 nmol.120min.l-1; P<0.05). Expression of SREBP-1c and FAS in adipose tissue was significantly down-regulated whereas expression of PDK4 and HSL was significantly up-regulated in both groups (P<0.05).Conclusions: When energy expenditure and energy deficit are matched, vigorous or moderate-intensity exercise combined with energy restriction provide broadly similar (positive) changes in metabolic control and adipose tissue gene expression.