Chronic medium-chain triacylglycerol consumption and endurance performance in trained runners.
BACKGROUND
This study was designed to assess the effects of chronic consumption of medium-chain triacylglycerols (MCT) on endurance running performance.


METHODS



METHODS
participants completed the study in a randomized, cross-over, placebo-controlled, double-blind fashion.


METHODS
participants were recruited from the general community to participate in this university based study.


METHODS
twelve trained male endurance runners (30.5+/-5.2 years of age) completed the study.


METHODS
participants consumed dietary supplements containing either 56 g of corn oil (LCT) or 60 g of MCT oil daily for 2 weeks. Following each dietary phase, participants completed a maximal treadmill test followed by an endurance treadmill test in which participants ran at 85% VO2max for 30 min proceeded by 75% VO2max until exhaustion.


METHODS
blood was taken at rest and after 45 min of exercise to assess concentrations of lactate, glucose, beta-hydroxybutyrate (beta-HBA), free fatty acids (FFA), glycerol and triacylglycerols (TG). Performance was assessed as time to exhaustion.


RESULTS
VO2max (72.0+/-8.0 vs 72.4+/- 9.0 ml x kg(-1) x min(-1)) and endurance time (99.8+/-23.5 vs 106.5+/-29.4 min) did not differ (p>0.05) between MCT and LCT trials, respectively. No differences (p>0.05) in lactate, glucose, beta-HBA, FFA, glycerol or TG were detected between trials. Respiratory exchange ratio (RER) was higher (p<0.05) at 15 min for the MCT trial (0.97+/-0.10) versus the LCT trial (0.90+/-0.20), but was similar between trials at other timepoints.


CONCLUSIONS
Results indicate that chronic MCT consumption neither enhances endurance nor significantly alters performance-related metabolism in trained male runners.
Misell
L M
LM
Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92182-7251, USA.
Lagomarcino
N D
ND
Schuster
V
V
Kern
M
M
D000328:Adult; D000704:Analysis of Variance; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology; D014280:Triglycerides / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood
D004041:Dietary Fats; D014280:Triglycerides