PMID- 10208253
OWN - NLM
STAT- MEDLINE
DCOM- 19990527
LR  - 20131121
IS  - 0301-5548 (Print)
IS  - 0301-5548 (Linking)
VI  - 79
IP  - 5
DP  - 1999 Apr
TI  - The effects of alterations in dietary carbohydrate intake on the performance of 
      high-intensity exercise in trained individuals.
PG  - 433-42
AB  - This study was designed to examine the effects of alterations in dietary 
      carbohydrate (CHO) intake on the performance of high-intensity exercise lasting 
      approximately 10 min (EXP 1) and 30 min (EXP 2). Trained subjects exercised to 
      exhaustion on four occasions on a cycle ergometer at 90% of maximal oxygen 
      consumption (VO2max; EXP 1, n = 5) and 80% of VO2max (EXP 2, n = 7). The first 
      two tests were familiarisation trials and were carried out following the 
      subjects' normal diet. Normal training was continued but standardised during the 
      periods of dietary control. The subsequent two tests were performed 2 weeks apart 
      after 7 days of dietary manipulation. The two diets were a 70% and a 40% CHO 
      diet, isoenergetic with each subject's normal diet and administered in a 
      randomised order. At both exercise intensities, time to exhaustion following the 
      high CHO and low CHO diets was not different [mean (SD) EXP 1: 11.56 (3.78) min 
      and 8.95 (2.35) min, P = 0.22; EXP 2: 26.9 (7.4) min and 26.5 (6.5) min, P = 
      0.90]. No differences in resting blood metabolite concentrations were found apart 
      from a lower beta-hydroxybutyrate (beta-HB) level following the high CHO diet in 
      EXP 2. Blood lactate was higher after exercise at 90% of VO2max following the 
      high CHO diet. Blood lactate was higher, and beta-HB lower during exercise at 80% 
      of VO2max following the high CHO diet. No differences were found in the other 
      blood metabolites tested. The respiratory exchange ratio after 15 min of exercise 
      at 80% of VO2max was higher on the high CHO diet. No differences in oxygen 
      uptake, heart rate (EXP 2) or ratings of perceived exertion (both experiments) 
      were found between conditions. These results indicate that moderate changes in 
      diet composition during training do not affect the performance of high-intensity 
      exercise in trained individuals when the total energy intake is moderately high.
FAU - Pitsiladis, Y P
AU  - Pitsiladis YP
AD  - Department of Biomedical Sciences, University Medical School, Aberdeen, UK.
FAU - Maughan, R J
AU  - Maughan RJ
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Eur J Appl Physiol Occup Physiol
JT  - European journal of applied physiology and occupational physiology
JID - 0410266
RN  - 0 (Dietary Carbohydrates)
RN  - 33X04XA5AT (Lactic Acid)
RN  - TZP1275679 (3-Hydroxybutyric Acid)
SB  - IM
MH  - 3-Hydroxybutyric Acid/blood
MH  - Adult
MH  - Dietary Carbohydrates/*administration & dosage
MH  - Energy Intake
MH  - Ergometry
MH  - Exercise/*physiology
MH  - Heart Rate
MH  - Humans
MH  - Kinetics
MH  - Lactic Acid/blood
MH  - Male
MH  - Oxygen Consumption
MH  - Physical Endurance
MH  - Physical Exertion
EDAT- 1999/04/20 00:00
MHDA- 1999/04/20 00:01
CRDT- 1999/04/20 00:00
PHST- 1999/04/20 00:00 [pubmed]
PHST- 1999/04/20 00:01 [medline]
PHST- 1999/04/20 00:00 [entrez]
AID - 10.1007/s004210050534 [doi]
PST - ppublish
SO  - Eur J Appl Physiol Occup Physiol. 1999 Apr;79(5):433-42. doi: 
      10.1007/s004210050534.