PMID- 17465601
OWN - NLM
STAT- MEDLINE
DCOM- 20070712
LR  - 20181113
IS  - 0112-1642 (Print)
IS  - 0112-1642 (Linking)
VI  - 37
IP  - 4-5
DP  - 2007
TI  - Regulation of substrate use during the marathon.
PG  - 332-6
AB  - The energy required to run a marathon is mainly provided through oxidative 
      phosphorylation in the mitochondria of the active muscles. Small amounts of 
      energy from substrate phosphorylation are also required during transitions and 
      short periods when running speed is increased. The three inputs for adenosine 
      triphosphate production in the mitochondria include oxygen, free adenosine 
      diphosphate and inorganic phosphate, and reducing equivalents. The reducing 
      equivalents are derived from the metabolism of fat and carbohydrate (CHO), which 
      are mobilised from intramuscular stores and also delivered from adipose tissue 
      and liver, respectively. The metabolism of fat and CHO is tightly controlled at 
      several regulatory sites during marathon running. Slower, recreational runners 
      run at 60-65% maximal oxygen uptake (VO(2max)) for approximately 3:45:00 and 
      faster athletes run at 70-75% for approximately 2:45:00. Both groups rely heavily 
      on fat and CHO fuels. However, elite athletes run marathons at speeds requiring 
      between 80% and 90% VO(2max), and finish in times between 2:05:00 and 2:20:00. 
      They are highly adapted to oxidise fat and must do so during training. However, 
      they compete at such high running speeds, that CHO oxidation (also highly 
      adapted) may be the exclusive source of energy while racing. Further work with 
      elite athletes is needed to examine this possibility.
FAU - Spriet, Lawrence L
AU  - Spriet LL
AD  - Department of Human Health and Nutritional Sciences, University of Guelph, 
      Guelph, Ontario, Canada. lspriet@uoguelph.ca
LA  - eng
PT  - Journal Article
PL  - New Zealand
TA  - Sports Med
JT  - Sports medicine (Auckland, N.Z.)
JID - 8412297
SB  - IM
MH  - Humans
MH  - Mitochondria, Muscle/*metabolism
MH  - Ontario
MH  - *Oxidative Phosphorylation
MH  - Physical Exertion/*physiology
MH  - Running/*physiology
EDAT- 2007/05/01 09:00
MHDA- 2007/07/13 09:00
CRDT- 2007/05/01 09:00
PHST- 2007/05/01 09:00 [pubmed]
PHST- 2007/07/13 09:00 [medline]
PHST- 2007/05/01 09:00 [entrez]
AID - 37NaN15 [pii]
AID - 10.2165/00007256-200737040-00015 [doi]
PST - ppublish
SO  - Sports Med. 2007;37(4-5):332-6. doi: 10.2165/00007256-200737040-00015.