The effect of a 3-month low-intensity endurance training program on fat oxidation and acetyl-CoA carboxylase-2 expression.
Endurance training has been shown to increase fat oxidation both at rest and during exercise. However, most exercise training studies have been performed at high exercise intensity in well-trained athletes, and not much is known about the effect of a low-intensity training program on fat oxidation capacity in lean sedentary humans. Here, we examine the effect of 3-month low-intensity training program on total and intramuscular triglyceride (IMTG)- and/or VLDL-derived fat oxidation capacity and skeletal muscle mRNA expression. Six healthy untrained subjects (aged 43 +/- 2 years, BMI 22.7 +/- 1.1 kg/ m(2), V(O)(2max) 3.2 +/- 0.2 l/min) participated in a supervised 12-week training program at 40% V(O)(2max) three times weekly. Total and plasma-derived fatty acid oxidation at rest and during 1 h exercise was measured using [(13)C]palmitate, and in a separate test, [(13)C]acetate recovery was determined. Muscle biopsies were taken after an overnight fast. Total fat oxidation during exercise increased from 1,241 +/- 93 to 1,591 +/- 130 micromol/min (P = 0.06), and IMTG- and/or VLDL-derived fatty acid oxidation increased from 236 +/- 84 to 639 +/- 172 micromol/min (P = 0.09). Acetyl-CoA carboxylase-2 mRNA expression was significantly decreased after training (P = 0.005), whereas lipoprotein lipase mRNA expression tended to increase (P = 0.07). In conclusion, a minimal amount of physical activity tends to increase fat oxidation and leads to marked changes in the expression of genes encoding for key enzymes in fat metabolism.
Schrauwen
Patrick
P
Department of Human Biology, Nutrition, Toxicology and Environmental Research Institute (NUTRIM), Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands. p.schrauwen@hb.unimaas.nl
van Aggel-Leijssen
Dorien P C
DP
Hul
Gabby
G
Wagenmakers
Anton J M
AJ
Vidal
Hubert
H
Saris
Wim H M
WH
van Baak
Marleen A
MA
D000103:Acetyl-CoA Carboxylase / Q000235:genetics*; D000328:Adult; D015992:Body Mass Index; D015444:Exercise / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008071:Lipoprotein Lipase / Q000235:genetics; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000201:enzymology; D010807:Physical Endurance; D012333:RNA, Messenger / Q000235:genetics; D012016:Reference Values; D013997:Time Factors; D014158:Transcription, Genetic; D014280:Triglycerides / Q000378:metabolism
D012333:RNA, Messenger; D014280:Triglycerides; D008071:Lipoprotein Lipase; D000103:Acetyl-CoA Carboxylase