PMID- 8872649
OWN - NLM
STAT- MEDLINE
DCOM- 19970123
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 81
IP  - 2
DP  - 1996 Aug
TI  - Carbohydrate ingestion and single muscle fiber glycogen metabolism during 
      prolonged running in men.
PG  - 801-9
AB  - The aim of this study was to examine the effect of carbohydrate (CHO) ingestion 
      on glycogen degradation in type I and type II muscle fibers during prolonged 
      running by using a quantitative biochemical method. To this end, eight male 
      subjects ran at 70% maximal oxygen uptake to exhaustion on a motorized treadmill 
      on two occasions, 1 wk apart. On each occasion, the subjects ingested 8 ml/kg 
      body wt of either placebo (Pl) or a 5.5% CHO-electrolyte solution (CHO-E) 
      immediately before the start of the run and 2 ml/kg body wt every 20 min 
      thereafter. Needle biopsy samples were obtained from the vastus lateralis muscle 
      before and after each trial and also at the time coinciding with Pl exhaustion in 
      the CHO-E trial. Running time to exhaustion was longer (P < 0.01) in the CHO-E 
      trial compared with the Pl trial (132.4 +/- 12.3 and 104.3 +/- 8.6 min, 
      respectively). A 25% reduction in glycogen utilization in type I fibers only was 
      observed in the CHO-E trial compared with the Pl trial (215.2 +/- 27.5 vs. 285.4 
      +/- 30.1 mmol/kg dry wt; P < 0.01). Furthermore, in the CHO-E trial, in contrast 
      to the Pl trial, both muscle ATP and phosphocreatine concentrations were well 
      maintained throughout exercise. Therefore, because in both the Pl and CHO-E 
      trials the type I fibers were glycogen depleted at the point of exhaustion (31.6 
      +/- 10.3 and 28.1 +/- 7.1 mmol/kg dry wt, respectively), it is proposed that CHO 
      ingestion improved endurance capacity by contributing to oxidative ATP production 
      specifically in type I fibers and by doing so delayed the development of glycogen 
      depletion in this fiber type.
FAU - Tsintzas, O K
AU  - Tsintzas OK
AD  - Department of Physical Education, Sports Science, and Recreation Management, 
      Loughborough University, Lercestershire, United Kingdom.
FAU - Williams, C
AU  - Williams C
FAU - Boobis, L
AU  - Boobis L
FAU - Greenhaff, P
AU  - Greenhaff P
LA  - eng
PT  - Clinical Trial
PT  - Controlled Clinical Trial
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 (Insulin)
RN  - 0 (Lipids)
RN  - 33X04XA5AT (Lactic Acid)
RN  - 9005-79-2 (Glycogen)
SB  - IM
MH  - Adult
MH  - Anaerobic Threshold/drug effects
MH  - Blood Glucose/metabolism
MH  - Dietary Carbohydrates/*pharmacology
MH  - Drinking
MH  - Exercise/*physiology
MH  - Glycogen/*metabolism
MH  - Heart Rate/drug effects/physiology
MH  - Humans
MH  - Insulin/blood
MH  - Lactic Acid/blood
MH  - Lipids/blood
MH  - Male
MH  - Muscle Fatigue/drug effects/physiology
MH  - Muscle Fibers, Fast-Twitch/drug effects/*metabolism
MH  - Muscle Fibers, Slow-Twitch/drug effects/*metabolism
MH  - Muscle, Skeletal/cytology/drug effects/*metabolism
MH  - Oxygen Consumption/drug effects/physiology
MH  - Plasma Volume/drug effects/physiology
MH  - *Running
MH  - Weight Loss/drug effects/physiology
EDAT- 1996/08/01 00:00
MHDA- 1996/08/01 00:01
CRDT- 1996/08/01 00:00
PHST- 1996/08/01 00:00 [pubmed]
PHST- 1996/08/01 00:01 [medline]
PHST- 1996/08/01 00:00 [entrez]
AID - 10.1152/jappl.1996.81.2.801 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1996 Aug;81(2):801-9. doi: 10.1152/jappl.1996.81.2.801.