Exercise training-induced effects on the abdominal subcutaneous adipose tissue phenotype in obese humans.

BACKGROUND: Rodent studies have indicated that physical exercise may improve adipose tissue function. We investigated the effects of a 12-weeks supervised, progressive exercise training program on adipocyte morphology and abdominal subcutaneous adipose tissue function in metabolically well-phenotyped, obese subjects.

METHODS: 21 obese men participated in a 12-weeks supervised, progressive, combined exercise training program, consisting of aerobic exercise (30min at 70% of Wmax , 2x/week) and resistance exercise (3x10 repetitions at 60% of 1RM, 1x/week), with adjustment of exercise intensity every 4 weeks. At baseline and after intervention, abdominal subcutaneous adipose tissue biopsies were collected to determine 1) adipocyte morphology, 2) gene expression of markers for lipolysis, inflammation, browning, adipokines and mitochondrial biogenesis/function, 3) protein expression of mitochondrial oxidative phosphorylation (OXPHOS) complexes and 4) ex vivo basal and β2 -adrenergic stimulated lipolysis.

RESULTS: The exercise training program, which increased maximal aerobic capacity (P<0.001) and muscle strength (P<0.001), slightly reduced adipose tissue mass (~ 0.7 kg, P=0.021) but did not affect abdominal subcutaneous adipocyte size (P=0.744), adipose tissue gene expression of markers for mitochondrial biogenesis and function, browning, lipolysis, inflammation and adipokines, total OXPHOS protein content (P=0.789) and β2 -adrenergic sensitivity of lipolysis (P=0.555).

CONCLUSIONS: A 12-weeks supervised, progressive exercise training program did neither alter abdominal subcutaneous adipocyte morphology and adipose tissue gene/protein expression of markers related to adipose tissue function, nor β2 -adrenergic sensitivity of lipolysis in obese male subjects.