Article

BACKGROUND: To better understand how prolonged electrical muscle stimulation can
improve cardiorespiratory risk markers in obese subjects, we investigated the
effect of prolonged combined thermal and electrical muscle stimulation (cTEMS) on
peak oxygen consumption (VO2peak) and body composition with subsequent lipolytic
and mitochondrial activity in adipocytes. RESULTS: Eleven obese (BMI
>/= 30 kg/m(2)) individuals received cTEMS in three 60-minute sessions per week
for 8 weeks. Activity levels and dietary habits were kept unchanged. Before and
after the stimulation period, functional capacity was assessed by VO2peak, and
body composition was analysed. Lipolytic activity was determined in abdominal
adipose tissue by 24 hours of microdialysis on a sedentary day, and adipose
tissue biopsies were taken for the gene expression analysis. Eight weeks of cTEMS
significantly increased VO2peak from 28.9 +/- 5.7 to 31.7 +/- 6.2 ml/kg/min (p <
0.05), corresponding to an average increase of 1.2% per week. Oxygen uptake and
work capacity also increased at the anaerobic threshold. Mean microdialytic
glycerol concentration over 24 hours, an index of sedentary lipolytic activity,
increased from 238 +/- 60 to 306 +/- 55 microM (p < 0,0001), but no significant
changes in body composition were observed. In addition, PGC-1alpha and
carnitine-palmitoyltransferase-2 mRNAs were significantly upregulated in
subcutaneous abdominal adipose tissue. CONCLUSIONS: In obese individuals with
unchanged lifestyles, 8 weeks of cTEMS significantly improved functional capacity
towards a higher fatigue resistance. This increase also gave rise to elevated
lipolytic activity and increased mitochondrial activity in abdominal adipose
tissue.
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Langue : ANGLAIS