PMID- 29333721
OWN - NLM
STAT- MEDLINE
DCOM- 20181218
LR  - 20210109
IS  - 2051-817X (Electronic)
IS  - 2051-817X (Linking)
VI  - 6
IP  - 1
DP  - 2018 Jan
TI  - Carbohydrate dose influences liver and muscle glycogen oxidation and performance 
      during prolonged exercise.
LID - 10.14814/phy2.13555 [doi]
LID - e13555
AB  - This study investigated the effect of carbohydrate (CHO) dose and composition on 
      fuel selection during exercise, specifically exogenous and endogenous (liver and 
      muscle) CHO oxidation. Ten trained males cycled in a double-blind randomized 
      order on 5 occasions at 77% V O2max for 2 h, followed by a 30-min time-trial (TT) 
      while ingesting either 60 g.h(-1) (LG) or 75 g.h(-1)(13) C-glucose (HG), 
      90 g.h(-1) (LGF) or 112.5 g.h(-1)(13) C-glucose-(13) C-fructose ([2:1] HGF) or 
      placebo. CHO doses met or exceed reported intestinal transporter saturation for 
      glucose and fructose. Indirect calorimetry and stable mass isotope [(13) C] 
      tracer techniques were utilized to determine fuel use. TT performance was 93% 
      "likely/probable" to be improved with LGF compared with the other CHO doses. 
      Exogenous CHO oxidation was higher for LGF and HGF compared with LG and HG 
      (ES > 1.34, P < 0.01), with the relative contribution of LGF (24.5 +/- 5.3%) 
      moderately higher than HGF (20.6 +/- 6.2%, ES = 0.68). Increasing CHO dose beyond 
      intestinal saturation increased absolute (29.2 +/- 28.6 g.h(-1) , ES = 1.28, 
      P = 0.06) and relative muscle glycogen utilization (9.2 +/- 6.9%, ES = 1.68, 
      P = 0.014) for glucose-fructose ingestion. Absolute muscle glycogen oxidation 
      between LG and HG was not significantly different, but was moderately higher for 
      HG (ES = 0.60). Liver glycogen oxidation was not significantly different between 
      conditions, but absolute and relative contributions were moderately attenuated 
      for LGF (19.3 +/- 9.4 g.h(-1) , 6.8 +/- 3.1%) compared with HGF (30.5 +/- 17.7 g.h(-1) 
      , 10.1 +/- 4.0%, ES = 0.79 & 0.98). Total fat oxidation was suppressed in HGF 
      compared with all other CHO conditions (ES > 0.90, P = 0.024-0.17). In 
      conclusion, there was no linear dose response for CHO ingestion, with 90 g.h(-1) 
      of glucose-fructose being optimal in terms of TT performance and fuel selection.
CI  - (c) 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on 
      behalf of The Physiological Society and the American Physiological Society.
FAU - King, Andy J
AU  - King AJ
AUID- ORCID: 0000-0002-3647-7025
AD  - Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett 
      University, Leeds, United Kingdom.
FAU - O'Hara, John P
AU  - O'Hara JP
AUID- ORCID: 0000-0003-1589-7984
AD  - Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett 
      University, Leeds, United Kingdom.
FAU - Morrison, Douglas J
AU  - Morrison DJ
AD  - Scottish Universities Environmental Research Centre, East Kilbride, United 
      Kingdom.
FAU - Preston, Tom
AU  - Preston T
AD  - Scottish Universities Environmental Research Centre, East Kilbride, United 
      Kingdom.
FAU - King, Roderick F G J
AU  - King RFGJ
AD  - Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett 
      University, Leeds, United Kingdom.
LA  - eng
PT  - Journal Article
PT  - Randomized Controlled Trial
PL  - United States
TA  - Physiol Rep
JT  - Physiological reports
JID - 101607800
RN  - 0 (Dietary Sugars)
RN  - 9005-79-2 (Glycogen)
SB  - IM
MH  - Adult
MH  - Dietary Sugars/administration & dosage/*metabolism
MH  - *Exercise
MH  - Glycogen/*metabolism
MH  - Humans
MH  - Liver/*metabolism
MH  - Male
MH  - Muscle, Skeletal/*metabolism
MH  - Oxidation-Reduction
PMC - PMC5789655
OTO - NOTNLM
OT  - Carbohydrate ingestion
OT  - exercise
OT  - metabolism
OT  - muscle glycogen
OT  - stable isotope
EDAT- 2018/01/16 06:00
MHDA- 2018/12/19 06:00
PMCR- 2018/01/15
CRDT- 2018/01/16 06:00
PHST- 2017/11/29 00:00 [received]
PHST- 2017/12/04 00:00 [revised]
PHST- 2017/12/05 00:00 [accepted]
PHST- 2018/01/16 06:00 [entrez]
PHST- 2018/01/16 06:00 [pubmed]
PHST- 2018/12/19 06:00 [medline]
PHST- 2018/01/15 00:00 [pmc-release]
AID - PHY213555 [pii]
AID - 10.14814/phy2.13555 [doi]
PST - ppublish
SO  - Physiol Rep. 2018 Jan;6(1):e13555. doi: 10.14814/phy2.13555.