PMID- 9536855
OWN - NLM
STAT- MEDLINE
DCOM- 19980421
LR  - 20190719
IS  - 0007-1145 (Print)
IS  - 0007-1145 (Linking)
VI  - 79
IP  - 2
DP  - 1998 Feb
TI  - Utilization of lipids during exercise in human subjects: metabolic and dietary 
      constraints.
PG  - 117-28
AB  - During endurance exercise, skeletal muscle relies mainly on both carbohydrate 
      (CHO) and fat oxidation to cover energy needs. Numerous scientific studies have 
      shown that increasing the exercise intensity leads to a progressive utilization 
      of CHO. The latter will induce a state of glycogen depletion which is generally 
      recognized as being a limiting factor for the continuation of strenuous exercise. 
      Different dietary interventions have been proposed to overcome this limitation. A 
      high-CHO diet during periods of intense training and competition, as well as CHO 
      intake during exercise, are known to maintain a high rate of CHO oxidation and to 
      delay fatigue. However, it has been recognized also that enhancing fatty acid 
      (FA) oxidation during exercise induces a reduced rate of glycogen degradation, 
      resulting in an improved endurance capacity. This is most strikingly observed as 
      a result of frequent endurance exercise which improves a number of factors known 
      to govern the FA flux and the oxidative capacity of skeletal muscle. Such factors 
      are: (1) blood flow and capillarization; (2) lipolysis of triacylglycerol (TAG) 
      in adipose tissue and circulating TAG and transport of FA from blood plasma to 
      the sarcoplasm; (3) availability and rate of hydrolysis of intramuscular TAG; (4) 
      activation of the FA and transport across the mitochondrial membrane; (5) the 
      activity of enzymes in the oxidative pathway; (6) hormonal adaptations, i.e. 
      sensitivity to catecholamines and insulin. The observation that the plasma FA 
      concentration is an important factor in determining the rate of FA oxidation, and 
      that some dietary factors may influence the rate of FA supply to muscle as well 
      as to the mitochondria, has led to a number of dietary interventions with the 
      ultimate goal to enhance FA oxidation and endurance performance. It appears that 
      experimental data are not equivocal that dietary interventions, such as a 
      high-fat diet, medium-chain TAG-fat emulsions and caffeine intake during 
      exercise, as well as L-carnitine supplementation, do significantly enhance FA 
      oxidation during exercise. So far, only regular endurance exercise can be 
      classified as successful in achieving adaptations which enhance FA mobilization 
      and oxidation.
FAU - Brouns, F
AU  - Brouns F
AD  - Department of Human Biology, Nutrition Toxicology and Environment Research 
      Institute, Maastricht, The Netherlands. F.Brouns@hb.unimaas.nl
FAU - van der Vusse, G J
AU  - van der Vusse GJ
LA  - eng
PT  - Journal Article
PT  - Review
PL  - England
TA  - Br J Nutr
JT  - The British journal of nutrition
JID - 0372547
RN  - 0 (Dietary Fats)
RN  - 0 (Fatty Acids)
RN  - 3G6A5W338E (Caffeine)
RN  - S7UI8SM58A (Carnitine)
SB  - IM
MH  - Caffeine/metabolism
MH  - Carnitine/metabolism
MH  - *Diet
MH  - Dietary Fats/metabolism
MH  - Exercise/*physiology
MH  - Fatty Acids/metabolism
MH  - Humans
MH  - *Lipid Metabolism
MH  - Muscle, Skeletal/*metabolism
MH  - Physical Education and Training
RF  - 153
EDAT- 1998/04/16 00:00
MHDA- 1998/04/16 00:01
CRDT- 1998/04/16 00:00
PHST- 1998/04/16 00:00 [pubmed]
PHST- 1998/04/16 00:01 [medline]
PHST- 1998/04/16 00:00 [entrez]
AID - S0007114598000233 [pii]
AID - 10.1079/bjn19980022 [doi]
PST - ppublish
SO  - Br J Nutr. 1998 Feb;79(2):117-28. doi: 10.1079/bjn19980022.