PMID- 10589859
OWN - NLM
STAT- MEDLINE
DCOM- 19991221
LR  - 20190831
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 31
IP  - 11
DP  - 1999 Nov
TI  - Increased fat availability enhances the capacity of trained individuals to 
      perform prolonged exercise.
PG  - 1570-9
AB  - METHODS: After a familiarization period, six well-trained males participated in a 
      diet and exercise regimen lasting 9 d and comprising three cycling tests to 
      exhaustion. A work rate was selected during the familiarization period that would 
      result in fatigue after approximately 90-100 min at an ambient temperature of 10 
      degrees C (i.e., approximately 75% of VO2max). The first exercise test was a 
      depletion trial and was preceded by a period during which the subjects' normal 
      diet was consumed. A prescribed 70% carbohydrate (CHO) diet was then consumed for 
      3.5 d. After this diet, a second exercise test was performed; one of two 
      isoenergetic experimental meals was consumed 4 h before this test (70% CHO meal, 
      CHO trial; or 90% fat meal, fat trial). The second exercise test was followed by 
      a further 3.5-d period on the high CHO diet. Four hours before the third test, 
      subjects consumed the other meal. Heparin was administered intravenously 30 min 
      (1000 U), 15 min (500 U), and 0 min (500 U) before exercise on the fat trial. 
      Subjects were assigned to the two meals in randomized order. RESULTS: Time to 
      exhaustion increased from 118.2 (12.4) min on the CHO trial to 127.9 (12.1) min 
      on the fat trial (P = 0.001). Although no difference in VO2, RER, HR or RPE was 
      found between trials, there was an earlier reduction in RER and an earlier rise 
      in RPE on the fat trial. No difference in total CHO oxidation was found between 
      trials (383 +/- 70 g on the CHO trial and 362 +/- 59 g on the fat trial). 
      CONCLUSIONS: These results suggest that increasing fat availability immediately 
      before exercise by acute fat feeding and heparin infusion can improve endurance 
      exercise in a cool environment in well-trained individuals. This study was not 
      intended to have immediate application to the sports performance field but rather 
      to contribute to our understanding of the factors that may limit endurance 
      performance. Heparin injection to elevate plasma fatty acid concentration would 
      not represent sound medical practice.
FAU - Pitsiladis, Y P
AU  - Pitsiladis YP
AD  - Department of Biomedical Sciences, University Medical School, Aberdeen, United 
      Kingdom.
FAU - Smith, I
AU  - Smith I
FAU - Maughan, R J
AU  - Maughan RJ
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - 0 (Anticoagulants)
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Dietary Fats)
RN  - 0 (Fatty Acids, Nonesterified)
RN  - 0 (Lactates)
RN  - 0 (Triglycerides)
RN  - 9005-49-6 (Heparin)
RN  - PDC6A3C0OX (Glycerol)
SB  - IM
MH  - Adult
MH  - Analysis of Variance
MH  - Anticoagulants/administration & dosage/pharmacology
MH  - Biological Availability
MH  - Blood Glucose/analysis
MH  - Dietary Carbohydrates/administration & dosage/pharmacokinetics
MH  - Dietary Fats/administration & dosage/*pharmacokinetics
MH  - Exercise Test
MH  - Exercise Tolerance/*physiology
MH  - Fatigue/physiopathology
MH  - Fatty Acids, Nonesterified/blood
MH  - Glycerol/blood
MH  - Heart Rate/physiology
MH  - Heparin/administration & dosage/pharmacology
MH  - Humans
MH  - Lactates/blood
MH  - Male
MH  - Oxidation-Reduction
MH  - Oxygen Consumption/physiology
MH  - Perception
MH  - Physical Endurance/*physiology
MH  - Physical Exertion/physiology
MH  - Respiration
MH  - Time Factors
MH  - Triglycerides/blood
EDAT- 1999/12/10 00:00
MHDA- 1999/12/10 00:01
CRDT- 1999/12/10 00:00
PHST- 1999/12/10 00:00 [pubmed]
PHST- 1999/12/10 00:01 [medline]
PHST- 1999/12/10 00:00 [entrez]
AID - 10.1097/00005768-199911000-00012 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 1999 Nov;31(11):1570-9. doi: 
      10.1097/00005768-199911000-00012.