PMID- 8692031
OWN - NLM
STAT- MEDLINE
DCOM- 19960828
LR  - 20190725
IS  - 0026-0495 (Print)
IS  - 0026-0495 (Linking)
VI  - 45
IP  - 7
DP  - 1996 Jul
TI  - Effects of carbohydrate (CHO) and fat supplementation on CHO metabolism during 
      prolonged exercise.
PG  - 915-21
AB  - The aim of the study was to examine carbohydrate (CHO) utilization in subjects 
      receiving CHO or CHO + medium-chain triglycerides (MCT) supplements during 180 
      minutes of exercise at 50% maximal aerobic work rate ([Wmax] 57% maximal oxygen 
      consumption [VO2max]). In a double-blind crossover design, nine trained athletes 
      cycled four times. Subjects received a bolus of 4 mL x kg(-1) at the start and 2 
      mL x kg(-1) every 20 minutes during exercise of either a 150-g x L(-1) CHO 
      solution (CHO trial), an equicaloric 70 energy% (en%) CHO-30 en% MCT suspension 
      containing 29 g MCT (CHO + MCT trial), or a 150-g x L(-1) CHO (high-CHO [HCHO]) 
      solution plus 20 g MCT (HCHO + MCT trial). A fourth trial consisted of a 
      13C-background control trial (CON). The four trials were randomized. Before and 
      after the exercise bout, muscle biopsies were taken from the quadriceps muscle 
      and muscle glycogen levels were determined. During exercise, breath samples were 
      collected for estimation of exogenous and endogenous CHO oxidation. No 
      significant differences were detected in glycogen breakdown among the trials (277 
      +/- 14 mmol x kg dry weight(-1) CHO, 249 +/- 20 CHO + MCT, and 240 +/- 18 HCHO + 
      MCT) or in the respiratory exchange ratio during exercise. Mean exogenous CHO 
      oxidation rates during the final hour of exercise were 0.79, 0.63, and 0.73 g x 
      min(-1), respectively. No differences were observed between the trials regarding 
      exogenous or endogenous CHO oxidation. Plasma free fatty acid (FFA) 
      concentrations were elevated during exercise to a level of approximately 500 
      micromol x L(-1) and were comparable in all trials, whereas plasma ketone 
      concentrations significantly increased after MCT ingestion as compared with the 
      CHO trial. It is concluded that 29 g MCT co-ingested with CHO during 180 minutes 
      of exercise does not influence CHO utilization or glycogen breakdown.
FAU - Jeukendrup, A E
AU  - Jeukendrup AE
AD  - Department of Human Biology, Nutrition Research Centre, University of Limburg, 
      Maastricht, The Netherlands.
FAU - Saris, W H
AU  - Saris WH
FAU - Brouns, F
AU  - Brouns F
FAU - Halliday, D
AU  - Halliday D
FAU - Wagenmakers, J M
AU  - Wagenmakers JM
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PL  - United States
TA  - Metabolism
JT  - Metabolism: clinical and experimental
JID - 0375267
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Dietary Fats)
RN  - 0 (Fatty Acids, Nonesterified)
RN  - 0 (Ketone Bodies)
RN  - 0 (Triglycerides)
RN  - 9005-79-2 (Glycogen)
RN  - PDC6A3C0OX (Glycerol)
SB  - IM
MH  - Adult
MH  - *Carbohydrate Metabolism
MH  - Cross-Over Studies
MH  - Dietary Carbohydrates/*administration & dosage/adverse effects
MH  - Dietary Fats/*administration & dosage/adverse effects
MH  - Digestive System/drug effects
MH  - Double-Blind Method
MH  - Exercise/*physiology
MH  - Fatty Acids, Nonesterified/blood
MH  - Glycerol/blood
MH  - Glycogen/metabolism
MH  - Humans
MH  - Ketone Bodies/blood
MH  - Male
MH  - Muscle, Skeletal/metabolism
MH  - Oxygen Consumption
MH  - Triglycerides/administration & dosage
EDAT- 1996/07/01 00:00
MHDA- 1996/07/01 00:01
CRDT- 1996/07/01 00:00
PHST- 1996/07/01 00:00 [pubmed]
PHST- 1996/07/01 00:01 [medline]
PHST- 1996/07/01 00:00 [entrez]
AID - S0026-0495(96)90169-9 [pii]
AID - 10.1016/s0026-0495(96)90169-9 [doi]
PST - ppublish
SO  - Metabolism. 1996 Jul;45(7):915-21. doi: 10.1016/s0026-0495(96)90169-9.