PMID- 23788576
OWN - NLM
STAT- MEDLINE
DCOM- 20140602
LR  - 20220226
IS  - 1522-1601 (Electronic)
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 115
IP  - 6
DP  - 2013 Sep
TI  - Direct and indirect lactate oxidation in trained and untrained men.
PG  - 829-38
LID - 10.1152/japplphysiol.00538.2013 [doi]
AB  - Lactate has been shown to be an important oxidative fuel. We aimed to quantify 
      the total lactate oxidation rate (Rox) and its direct vs. indirect (glucose that 
      is gluconeogenically derived from lactate and subsequently oxidized) components 
      (mg.kg(-1).min(-1)) during rest and exercise in humans. We also investigated the 
      effects of endurance training, exercise intensity, and blood lactate 
      concentration ([lactate]b) on direct and indirect lactate oxidation. Six 
      untrained (UT) and six trained (T) men completed 60 min of constant load exercise 
      at power outputs corresponding to their lactate threshold (LT). T subjects 
      completed two additional 60-min sessions of constant load exercise at 10% below 
      the LT workload (LT-10%), one of which included a lactate clamp (LC; LT-10%+LC). 
      Rox was higher at LT in T [22.7 +/- 2.9, 75% peak oxygen consumption (Vo2peak)] 
      compared with UT (13.4 +/- 2.5, 68% Vo2peak, P < 0.05). Increasing [lactate]b 
      (LT-10%+LC, 67% Vo2peak) significantly increased lactate Rox (27.9 +/- 3.0) 
      compared with its corresponding LT-10% control (15.9 +/- 2.2, P < 0.05). Direct and 
      indirect Rox increased significantly from rest to exercise, and their relative 
      partitioning remained constant in all trials but differed between T and UT: 
      direct oxidation comprised 75% of total lactate oxidation in UT and 90% in T, 
      suggesting the presence of training-induced adaptations. Partitioning of total 
      carbohydrate (CHO) use showed that subjects derived one-third of CHO energy from 
      blood lactate, and exogenous lactate infusion increased lactate oxidation 
      significantly, causing a glycogen-sparing effect in exercising muscle.
FAU - Emhoff, Chi-An W
AU  - Emhoff CA
AD  - Department of Integrative Biology, University of California, Berkeley, 
      California.
FAU - Messonnier, Laurent A
AU  - Messonnier LA
FAU - Horning, Michael A
AU  - Horning MA
FAU - Fattor, Jill A
AU  - Fattor JA
FAU - Carlson, Thomas J
AU  - Carlson TJ
FAU - Brooks, George A
AU  - Brooks GA
LA  - eng
GR  - R01 AR042906/AR/NIAMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130620
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Blood Glucose)
RN  - 142M471B3J (Carbon Dioxide)
RN  - 33X04XA5AT (Lactic Acid)
SB  - IM
MH  - Adult
MH  - Blood Glucose/metabolism
MH  - Carbon Dioxide/physiology
MH  - Exercise/*physiology
MH  - Exercise Test
MH  - Gluconeogenesis
MH  - Glycogenolysis
MH  - Humans
MH  - Kinetics
MH  - Lactic Acid/*blood
MH  - Male
MH  - Oxidation-Reduction
MH  - Physical Endurance/*physiology
MH  - Young Adult
PMC - PMC8846964
OTO - NOTNLM
OT  - exercise
OT  - gluconeogenesis
OT  - glucose
OT  - lactate oxidation
OT  - muscle glycogen
OT  - stable isotope tracers
OT  - training
COIS- G. A. Brooks has a financial interest in CytoSport; otherwise, the authors 
      declare no conflict of interest.
EDAT- 2013/06/22 06:00
MHDA- 2014/06/03 06:00
PMCR- 2014/09/15
CRDT- 2013/06/22 06:00
PHST- 2013/06/22 06:00 [entrez]
PHST- 2013/06/22 06:00 [pubmed]
PHST- 2014/06/03 06:00 [medline]
PHST- 2014/09/15 00:00 [pmc-release]
AID - japplphysiol.00538.2013 [pii]
AID - JAPPL-00538-2013 [pii]
AID - 10.1152/japplphysiol.00538.2013 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2013 Sep;115(6):829-38. doi: 
      10.1152/japplphysiol.00538.2013. Epub 2013 Jun 20.