PMID- 8282593
OWN - NLM
STAT- MEDLINE
DCOM- 19940214
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 75
IP  - 4
DP  - 1993 Oct
TI  - Carbohydrate supplementation spares muscle glycogen during variable-intensity 
      exercise.
PG  - 1477-85
AB  - Effects of carbohydrate (CHO) supplementation on muscle glycogen utilization and 
      endurance were evaluated in seven well-trained male cyclists during continuous 
      cycling exercise that varied between low [45% maximal O2 uptake (VO2 max)] and 
      moderate intensity (75% VO2 max). During each exercise bout the subjects received 
      either artificially flavored placebo (P), 10% liquid CHO supplement (L; 3 x 18 g 
      CHO/h), or solid CHO supplement (S; 2 x 25 g CHO/h). Muscle biopsies were taken 
      from vastus lateralis during P and L trials immediately before exercise and after 
      first (124 min) and second set (190 min) of intervals. Subjects then rode to 
      fatigue at 80% VO2 max. Plasma glucose and insulin responses during L treatment 
      reached levels of 6.7 +/- 0.7 mM and 70.6 +/- 17.2 microU/ml, respectively, and 
      were significantly greater than those of P treatment (4.4 +/- 0.1 mM and 17.7 +/- 
      1.6 microU/ml) throughout the exercise bout. Plasma glucose and insulin responses 
      of S treatment were intermediate to those of L and P treatments. Times to fatigue 
      for S (223.9 +/- 3.5 min) and L (233.4 +/- 7.5 min) treatments did not differ but 
      were significantly greater than that of P treatment (202.4 +/- 9.8 min). After 
      the first 190 min of exercise, muscle glycogen was significantly greater during L 
      (79 +/- 3.5 mumol/g wet wt) than during P treatment (58.5 +/- 7.2 mumol/g wet 
      wt). Furthermore, differences in muscle glycogen concentrations between L and P 
      treatments after 190 min of exercise and in time to fatigue for these treatments 
      were positively related (r = 0.76, P < 0.05). These results suggest that CHO 
      supplementation can enhance prolonged continuous variable-intensity exercise by 
      reducing dependency on muscle glycogen as a fuel source.
FAU - Yaspelkis, B B 3rd
AU  - Yaspelkis BB 3rd
AD  - Department of Kinesiology, University of Texas at Austin 78712.
FAU - Patterson, J G
AU  - Patterson JG
FAU - Anderla, P A
AU  - Anderla PA
FAU - Ding, Z
AU  - Ding Z
FAU - Ivy, J L
AU  - Ivy JL
LA  - eng
PT  - Journal Article
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 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Fatty Acids, Nonesterified)
RN  - 0 (Insulin)
RN  - 0 (Lactates)
RN  - 142M471B3J (Carbon Dioxide)
RN  - 33X04XA5AT (Lactic Acid)
RN  - 9005-79-2 (Glycogen)
SB  - IM
MH  - Adult
MH  - Bicycling
MH  - Blood Glucose/metabolism
MH  - Carbon Dioxide/metabolism
MH  - Dietary Carbohydrates/*pharmacology
MH  - Drinking/physiology
MH  - Ergometry
MH  - Exercise/*physiology
MH  - Fatty Acids, Nonesterified/blood
MH  - Glycogen/*metabolism
MH  - Heart Rate/drug effects/physiology
MH  - Humans
MH  - Insulin/blood
MH  - Lactates/blood
MH  - Lactic Acid
MH  - Male
MH  - Muscles/drug effects/*metabolism
MH  - Oxidation-Reduction
MH  - Oxygen Consumption/drug effects
MH  - Weight Loss/physiology
EDAT- 1993/10/01 00:00
MHDA- 1993/10/01 00:01
CRDT- 1993/10/01 00:00
PHST- 1993/10/01 00:00 [pubmed]
PHST- 1993/10/01 00:01 [medline]
PHST- 1993/10/01 00:00 [entrez]
AID - 10.1152/jappl.1993.75.4.1477 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1993 Oct;75(4):1477-85. doi: 10.1152/jappl.1993.75.4.1477.