PMID- 31295069
OWN - NLM
STAT- MEDLINE
DCOM- 20201009
LR  - 20201009
IS  - 1522-1601 (Electronic)
IS  - 0161-7567 (Linking)
VI  - 127
IP  - 3
DP  - 2019 Sep 1
TI  - Dynamics of the power-duration relationship during prolonged endurance exercise 
      and influence of carbohydrate ingestion.
PG  - 726-736
LID - 10.1152/japplphysiol.00207.2019 [doi]
AB  - We tested the hypotheses that the parameters of the power-duration relationship, 
      estimated as the end-test power (EP) and work done above EP (WEP) during a 3-min 
      all-out exercise test (3MT), would be reduced progressively after 40 min, 80 min, 
      and 2 h of heavy-intensity cycling and that carbohydrate (CHO) ingestion would 
      attenuate the reduction in EP and WEP. Sixteen participants completed a 3MT 
      without prior exercise (control), immediately after 40 min, 80 min, and 2 h of 
      heavy-intensity exercise while consuming a placebo beverage, and also after 2 h 
      of heavy-intensity exercise while consuming a CHO supplement (60 g/h CHO). There 
      was no difference in EP measured without prior exercise (260 +/- 37 W) compared 
      with EP after 40 min (268 +/- 39 W) or 80 min (260 +/- 40 W) of heavy-intensity 
      exercise; however, after 2 h EP was 9% lower compared with control (236 +/- 47 W; P 
      < 0.05). There was no difference in WEP measured without prior exercise 
      (17.9 +/- 3.3 kJ) compared with after 40 min of heavy-intensity exercise 
      (16.1 +/- 3.3 kJ), but WEP was lower (P < 0.05) than control after 80 min 
      (14.7 +/- 2.9 kJ) and 2 h (13.8 +/- 2.7 kJ). Compared with placebo, CHO ingestion 
      negated the reduction of EP following 2 h of heavy-intensity exercise (254 +/- 49 
      W) but had no effect on WEP (13.5 +/- 3.4 kJ). These results reveal a different 
      time course for the deterioration of EP and WEP during prolonged endurance 
      exercise and indicate that EP is sensitive to CHO availability.NEW & NOTEWORTHY 
      The parameters of the power-duration relationship [critical power (CP) and the 
      curvature constant (W')] have typically been considered to be static. Here we 
      report the time course for reductions in CP and W', as estimated with the 3-min 
      all-out cycle test, during 2 h of heavy-intensity exercise. We also show that 
      carbohydrate ingestion during exercise preserves CP, but not W', without altering 
      muscle glycogen depletion. These results provide new mechanistic and practical 
      insight into the power-duration curve and its relationship to exercise-related 
      fatigue development.
FAU - Clark, Ida E
AU  - Clark IE
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Vanhatalo, Anni
AU  - Vanhatalo A
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Thompson, Christopher
AU  - Thompson C
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Joseph, Charlotte
AU  - Joseph C
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Black, Matthew I
AU  - Black MI
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Blackwell, Jamie R
AU  - Blackwell JR
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Wylie, Lee J
AU  - Wylie LJ
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Tan, Rachel
AU  - Tan R
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Bailey, Stephen J
AU  - Bailey SJ
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
FAU - Wilkins, Brad W
AU  - Wilkins BW
AD  - Nike Sport Research Lab, Beaverton, Oregon.
FAU - Kirby, Brett S
AU  - Kirby BS
AD  - Nike Sport Research Lab, Beaverton, Oregon.
FAU - Jones, Andrew M
AU  - Jones AM
AUID- ORCID: 0000-0002-2082-1709
AD  - Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's 
      Campus, University of Exeter, Exeter, United Kingdom.
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
DEP - 20190711
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Dietary Carbohydrates)
SB  - IM
MH  - Adult
MH  - Dietary Carbohydrates/administration & dosage
MH  - Exercise/*physiology
MH  - Exercise Test
MH  - Humans
MH  - Male
MH  - Physical Endurance/*physiology
OTO - NOTNLM
OT  - endurance
OT  - exercise
OT  - fatigue
OT  - metabolism
OT  - nutrition
EDAT- 2019/07/12 06:00
MHDA- 2020/10/10 06:00
CRDT- 2019/07/12 06:00
PHST- 2019/07/12 06:00 [pubmed]
PHST- 2020/10/10 06:00 [medline]
PHST- 2019/07/12 06:00 [entrez]
AID - 10.1152/japplphysiol.00207.2019 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2019 Sep 1;127(3):726-736. doi: 
      10.1152/japplphysiol.00207.2019. Epub 2019 Jul 11.