PMID- 11711582
OWN - NLM
STAT- MEDLINE
DCOM- 20020122
LR  - 20190513
IS  - 0022-3751 (Print)
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 537
IP  - Pt 1
DP  - 2001 Nov 15
TI  - Phosphocreatine degradation in type I and type II muscle fibres during submaximal 
      exercise in man: effect of carbohydrate ingestion.
PG  - 305-11
AB  - 1. The aim of this study was to examine the effect of carbohydrate (CHO) 
      ingestion on changes in ATP and phosphocreatine (PCr) concentrations in different 
      muscle fibre types during prolonged running and relate those changes to the 
      degree of glycogen depletion. 2. Five male subjects performed two runs at 70 % 
      maximum oxygen uptake (.V(O2,max)), 1 week apart. Each subject ingested 8 ml (kg 
      body mass (BM))(-1) of either a placebo (Con trial) or a 5.5 % CHO solution (CHO 
      trial) immediately before each run and 2 ml (kg BM)(-1) every 20 min thereafter. 
      In the Con trial, the subjects ran to exhaustion (97.0 +/- 6.7 min). In the CHO 
      trial, the run was terminated at the time coinciding with exhaustion in the Con 
      trial. Muscle samples were obtained from the vastus lateralis before and after 
      each trial. 3. Carbohydrate ingestion did not affect ATP concentrations. However, 
      it attenuated the decline in PCr concentration by 46 % in type I fibres (CHO: 20 
      +/- 8 mmol (kg dry matter (DM))(-1); Con: 34 +/- 6 mmol (kg DM)(-1); P < 0.05) 
      and by 36 % in type II fibres (CHO: 30 +/- 5 mmol (kg DM)(-1); Con: 48 +/- 6 mmol 
      (kg DM)(-1); P < 0.05). 4. A 56 % reduction in glycogen utilisation in type I 
      fibres was observed in CHO compared with Con (117 +/- 39 vs. 240 +/- 32 mmol 
      glucosyl units (kg DM)(-1), respectively; P < 0.01), but no difference was 
      observed in type II fibres. 5. It is proposed that CHO ingestion during 
      exhaustive running attenuates the decline in oxidative ATP resynthesis in type I 
      fibres, as indicated by sparing of both PCr and glycogen breakdown. The 
      CHO-induced sparing of PCr, but not glycogen, in type II fibres may reflect 
      differential recruitment and/or role of PCr between fibre types.
FAU - Tsintzas, K
AU  - Tsintzas K
AD  - Human Muscle Metabolism Research Group, Loughborough University, Loughborough 
      LE11 3TU, UK. kostas.tzintzas@nottingham.ac.uk
FAU - Williams, C
AU  - Williams C
FAU - Constantin-Teodosiu, D
AU  - Constantin-Teodosiu D
FAU - Hultman, E
AU  - Hultman E
FAU - Boobis, L
AU  - Boobis L
FAU - Clarys, P
AU  - Clarys P
FAU - Greenhaff, P
AU  - Greenhaff P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
RN  - 0 (Dietary Carbohydrates)
RN  - 020IUV4N33 (Phosphocreatine)
SB  - IM
MH  - Adult
MH  - Blood/metabolism
MH  - Dietary Carbohydrates/*pharmacology
MH  - Exercise/*physiology
MH  - Heart Rate
MH  - Humans
MH  - Male
MH  - Muscle Fibers, Fast-Twitch/drug effects/*metabolism
MH  - Muscle Fibers, Slow-Twitch/drug effects/*metabolism
MH  - Oxygen Consumption
MH  - Phosphocreatine/*metabolism
MH  - Pulmonary Gas Exchange
MH  - Running/physiology
PMC - PMC2278942
EDAT- 2001/11/17 10:00
MHDA- 2002/01/23 10:01
PMCR- 2002/11/15
CRDT- 2001/11/17 10:00
PHST- 2001/11/17 10:00 [pubmed]
PHST- 2002/01/23 10:01 [medline]
PHST- 2001/11/17 10:00 [entrez]
PHST- 2002/11/15 00:00 [pmc-release]
AID - PHY_12976 [pii]
AID - 10.1111/j.1469-7793.2001.0305k.x [doi]
PST - ppublish
SO  - J Physiol. 2001 Nov 15;537(Pt 1):305-11. doi: 10.1111/j.1469-7793.2001.0305k.x.