Effect of endurance training on glycerol kinetics during strenuous exercise in humans.
Glycerol kinetics were evaluated during high-intensity exercise in five untrained and five endurance-trained subjects. Glycerol rate of appearance (Ra) in plasma was determined by infusing [2H5]glycerol during rest and 60 minutes of cycle ergometer exercise performed at 70% V02 peak. Mean plasma glycerol concentration was greater in trained than untrained subjects throughout exercise (P<.05). The average glycerol Ra during exercise and the integrated lipolytic response to exercise, expressed as total glycerol Ra above baseline, were both greater in trained (7.85 +/- 0.72 micromol x kg(-1) x min(-1) and 289 +/- 50 micromol x kg(-1) x h(-1), respectively) than in untrained (5.68 +/- 0.90 micromol x kg(-1) x min(-1), and 198 +/- 31 micromol x kg(-1) x h(-1), respectively) subjects (P<.05). We conclude that whole-body lipolytic rates are greater in endurance-trained athletes than in sedentary controls during high-intensity exercise performed at the same relative intensity.
Klein
S
S
Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110-1093, USA.
Weber
J M
JM
Coyle
E F
EF
Wolfe
R R
RR
D000328:Adult; D015444:Exercise; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D005990:Glycerol / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D010807:Physical Endurance; D014280:Triglycerides / Q000378:metabolism
D005230:Fatty Acids, Nonesterified; D014280:Triglycerides; D005990:Glycerol