PMID- 26296770
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20150822
LR  - 20181113
IS  - 2051-817X (Print)
IS  - 2051-817X (Electronic)
IS  - 2051-817X (Linking)
VI  - 3
IP  - 8
DP  - 2015 Aug
TI  - The effect of dehydration on muscle metabolism and time trial performance during 
      prolonged cycling in males.
LID - 10.14814/phy2.12483 [doi]
LID - e12483
AB  - This study combined overnight fluid restriction with lack of fluid intake during 
      prolonged cycling to determine the effects of dehydration on substrate oxidation, 
      skeletal muscle metabolism, heat shock protein 72 (Hsp72) response, and time 
      trial (TT) performance. Nine males cycled at ~65% VO2peak for 90 min followed by 
      a TT (6 kJ/kg BM) either with fluid (HYD) or without fluid (DEH). Blood samples 
      were taken every 20 min and muscle biopsies were taken at 0, 45, and 90 min of 
      exercise and after the TT. DEH subjects started the trial with a -0.6% BM from 
      overnight fluid restriction and were dehydrated by 1.4% after 45 min, 2.3% after 
      90 min of exercise, and 3.1% BM after the TT. There were no significant 
      differences in oxygen uptake, carbon dioxide production, or total sweat loss 
      between the trials. However, physiological parameters (heart rate [HR], rate of 
      perceived exertion, core temperature [Tc], plasma osmolality [Posm], plasma 
      volume [Pvol] loss, and Hsp72), and carbohydrate (CHO) oxidation and muscle 
      glycogen use were greater during 90 min of moderate cycling when subjects 
      progressed from 0.6% to 2.3% dehydration. TT performance was 13% slower when 
      subjects began 2.3% and ended 3.1% dehydrated. Throughout the TT, Tc, Posm, blood 
      and muscle lactate [La], and serum Hsp72 were higher, even while working at a 
      lower power output (PO). The accelerated muscle glycogen use during 90 min of 
      moderate intensity exercise with DEH did not affect subsequent TT performance, 
      rather augmented Tc, RPE and the additional physiological factors were more 
      important in slowing performance when dehydrated.
CI  - (c) 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on 
      behalf of the American Physiological Society and The Physiological Society.
FAU - Logan-Sprenger, Heather M
AU  - Logan-Sprenger HM
AD  - Canadian Sports Institute of Ontario, Toronto, Ontario, Canada 
      hsprenger@csiontario.ca.
FAU - Heigenhauser, George J F
AU  - Heigenhauser GJ
AD  - Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
FAU - Jones, Graham L
AU  - Jones GL
AD  - Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
FAU - Spriet, Lawrence L
AU  - Spriet LL
AD  - Department of Human Health and Nutritional Sciences, University of Guelph, 
      Ontario, Canada.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Physiol Rep
JT  - Physiological reports
JID - 101607800
PMC - PMC4562569
OTO - NOTNLM
OT  - Heat shock proteins
OT  - hydration
OT  - mild dehydration
OT  - muscle metabolism
OT  - performance
EDAT- 2015/08/25 06:00
MHDA- 2015/08/25 06:01
PMCR- 2015/08/21
CRDT- 2015/08/23 06:00
PHST- 2015/08/23 06:00 [entrez]
PHST- 2015/08/25 06:00 [pubmed]
PHST- 2015/08/25 06:01 [medline]
PHST- 2015/08/21 00:00 [pmc-release]
AID - 3/8/e12483 [pii]
AID - 10.14814/phy2.12483 [doi]
PST - ppublish
SO  - Physiol Rep. 2015 Aug;3(8):e12483. doi: 10.14814/phy2.12483.