Intramuscular triacyglycerol, glycogen and acetyl group metabolism during 4 h of moderate exercise in man

Abstract

This study investigated intramuscular triacylglycerol (IMTG) and glycogen utilisation, pyruvate dehydrogenase activation (PDHa) and acetyl group accumulation during prolonged moderate intensity exercise. Seven endurance-trained men cycled for 240 min at 57% maximal oxygen consumption (VO2,max) and duplicate muscle samples were obtained at rest and at 10,120 and 240 min of exercise. We hypothesised that IMTG utilisation would be augmented during 2-4 h of exercise, while PDHa would be decreased secondary to reduced glycogen metabolism. IMTG was measured on both muscle samples at each time point and the coefficient of variation was 12.3 ± 9.4 Whole body respiratory exchange ratio (RER) decrease..