PMID- 8806933
OWN - NLM
STAT- MEDLINE
DCOM- 19961203
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 80
IP  - 6
DP  - 1996 Jun
TI  - Effects of medium-chain triglyceride ingestion on fuel metabolism and cycling 
      performance.
PG  - 2217-25
AB  - On three occasions separated by 10 days, six endurance-trained cyclists rode for 
      2 h at 60% of peak O2 uptake and then performed a simulated 40-km time trial 
      (T-trial). During the rides, the subjects ingested a total of 2 liters of a 
      [U-14C]glucose-labeled beverage containing a random order of either 10% glucose 
      [carbohydrate (CHO)], 4.3% medium-chain triglycerides (MCTs); or 10% glucose + 
      4.3% MCTs (CHO+MCT). Although replacing CHO with MCTs slowed the T-trials from 
      66.8 +/- 0.4 (SE) to 72.1 +/- 0.6 min (P < 0.001), adding MCTs to CHO improved 
      the T-trials from 66.8 +/- 0.4 to 65.1 +/- 0.5 min (P < 0.05). Faster T-trials in 
      the CHO+MCT trial than in the CHO trial were associated with increased final 
      circulating concentrations of free fatty acids (0.58 +/- 0.09 vs. 0.36 +/- 0.06 
      mmol/l; P < 0.05) and ketones (1.51 +/- 0.25 vs. 0.51 +/- 0.07 mmol/l; P < 0.01) 
      and decreased final circulating concentrations of glucose (5.2 +/- 0.2 vs. 6.3 
      +/- 0.3 mmol/l; P < 0.01) and lactate (1.9 +/- 0.4 vs. 3.7 +/- 0.5 mmol/l; P < 
      0.05). Adding MCTs to ingested CHO reduced total CHO oxidation rates from 14 +/- 
      1 to 10 +/- 1 mmol/min at 2 h and from 17 +/- 1 to 14 +/- 1 mmol/min in the 
      T-trial (P < 0.01), without affecting the corresponding approximately 5 and 
      approximately 7 mmol/min rates of [14C]glucose oxidation. These data suggest that 
      MCT oxidation decreased the direct and/or indirect (via lactate) oxidation of 
      muscle glycogen. A reduced reliance on CHO oxidation at a given O2 uptake is 
      similar to an endurance-training effect, and that may explain the improved 
      T-trial performances.
FAU - Van Zyl, C G
AU  - Van Zyl CG
AD  - Liberty Life Chair of Exercise and Sport Science, University of Cape Town Medical 
      School, Observatory, South Africa.
FAU - Lambert, E V
AU  - Lambert EV
FAU - Hawley, J A
AU  - Hawley JA
FAU - Noakes, T D
AU  - Noakes TD
FAU - Dennis, S C
AU  - Dennis SC
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Triglycerides)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adult
MH  - Energy Metabolism/*drug effects
MH  - Exercise/*physiology
MH  - Glucose/metabolism
MH  - Humans
MH  - Male
MH  - Oxygen Consumption/*physiology
MH  - Task Performance and Analysis
MH  - Triglycerides/*pharmacology
EDAT- 1996/06/01 00:00
MHDA- 1996/06/01 00:01
CRDT- 1996/06/01 00:00
PHST- 1996/06/01 00:00 [pubmed]
PHST- 1996/06/01 00:01 [medline]
PHST- 1996/06/01 00:00 [entrez]
AID - 10.1152/jappl.1996.80.6.2217 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1996 Jun;80(6):2217-25. doi: 10.1152/jappl.1996.80.6.2217.