A single bout of whole-body resistance exercise augments basal VLDL-triacylglycerol removal from plasma in healthy untrained men

A single bout of prolonged aerobic exercise lowers plasma TAG (triacylglycerol) concentrations the next day by increasing the efficiency of VLDL (very-low-density lipoprotein)-TAG removal from the circulation. The effect of resistance exercise on VLDL-TAG metabolism is not known. Therefore we evaluated VLDL-TAG kinetics by using stable isotope-labelled tracers in eight healthy untrained men (age, 25.3±0.8 years; body mass index, 24.5±0.6 kg/m²) in the post-absorptive state in the morning on two separate occasions: once after performing a single 90-min bout of strenuous isokinetic resistance exercise (three sets×ten repetitions, 12 exercises at 80% of maximum peak torque production, with a 2-min rest interval between exercises) on the preceding afternoon and once after an equivalent period of rest. Fasting plasma VLDL-TAG concentrations in the morning after exercise were significantly lower than in the morning after rest (0.23±0.04 compared with 0.33±0.06 mmol/l respectively; P=0.001). Hepatic VLDL-TAG secretion rate was not different (P=0.31), but plasma clearance rate of VLDL-TAG was significantly higher (by 26±8%) after exercise than rest (31±3 compared with 25±3 ml/min respectively; P=0.004), and the mean residence time of VLDL-TAG in the circulation was significantly shorter (113±10 compared with 144±18 min respectively; P=0.02). Fasting plasma NEFA (non-esterified fatty acid; ‘free’ fatty acid) and serum β-hydroxybutyrate concentrations were both significantly higher after exercise than rest (P<0.05), whereas plasma glucose and serum insulin concentrations were not different (P>0.30). We conclude that, in healthy untrained men, a single bout of whole-body resistance exercise lowers fasting plasma VLDL-TAG concentrations by augmenting VLDL-TAG removal from plasma. The effect appears to be qualitatively and quantitatively similar to that reported previously for aerobic exercise.