Increased VLDL-TAG turnover during and after acute moderate-intensity exercise.
OBJECTIVE
Breakdown rates of very low density lipoprotein triacylglycerols (VLDL-TAG) were quantified before (3 h), during (45 min), and after (3 h) moderate physical exercise at 40% VO2 max in young sedentary subjects (four male and four female, age 29.8 +/-1.6 yr, BMI 24.1 +/- 0.9 kg x m, VO2max 37.0 +/- 1.7 mL x kg x min), using boluses of H5-glycerol (100 mu mol x kg) and H2-palmitate (6.6 mu mol x kg). The catabolic rates of VLDL-TAG were calculated from the decay in the isotopic enrichment using a single-pool model. The results were compared with those obtained during 6 h of rest in five of the same volunteers.


RESULTS
VLDL-TAG concentration remained constant throughout the study with exercise (P = NS). The fractional catabolic rate was nearly doubled from rest to exercise (P < 0.05 vs rest) and increased to an even greater extent during the early phase of recovery (P < 0.001 vs rest). During the late recovery phase, the value returned to the preexercise value (P = NS vs rest). The values for the absolute catabolic rate (kabs) followed the same trend.


CONCLUSIONS
VLDL-TAG turnover was increased during exercise and during the early phase of recovery.
Morio
Béatrice
B
Protein and Energy Metabolism Research Unit, Human Nutrition Laboratory, Clermont Ferrand, France.
Holmbäck
Ulf
U
Gore
Dennis
D
Wolfe
Robert R
RR
D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D003903:Deuterium; D015444:Exercise / Q000502:physiology*; D005260:Female; D005990:Glycerol; D006801:Humans; D016014:Linear Models; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D010168:Palmitates; D012129:Respiratory Function Tests; D014280:Triglycerides / Q000097:blood*
D008079:Lipoproteins, VLDL; D010168:Palmitates; D014280:Triglycerides; C030106:very low density lipoprotein triglyceride; D003903:Deuterium; D005990:Glycerol