Résumé
AIM: We investigated whether or not, in type 2 diabetic (T2D) patients, an individualized training effect on whole-body lipid oxidation would be associated with changes in muscle oxidative capacity. METHODS: Eleven T2D patients participated in the study. Whole-body lipid oxidation during exercise was assessed by indirect calorimetry during graded exercise. Blood samples for measuring blood glucose and free fatty acids during exercise, and muscle oxidative capacity measured from skeletal muscle biopsy (mitochondrial respiration and citrate synthase activity), were investigated in the patients before and after a 10-week individualized training program targeted at LIPOX(max), corresponding to the power at which the highest rate of lipids is oxidized (lipid oxidation at LIPOX(max)). RESULTS: Training induced both a shift to a higher-power intensity of LIPOX(max) (+9.1+/-4.2W; P<0.05) and an improvement of lipid oxidation at LIPOX(max) (+51.27+/-17.93mgmin(-1); P<0.05). The improvement in lipid oxidation was correlated with training-induced improvement in mitochondrial respiration (r=0.78; P<0.01) and citrate synthase activity (r=0.63; P<0.05). CONCLUSION: This study shows that a moderate training protocol targeted at the LIPOX(max) in T2D patients improves their ability to oxidize lipids during exercise, and that this improvement is associated with enhanced muscle oxidative capacity.