Abstract
To test the hypothesis that lactate plays a central role in the distribution of carbohydrate (CHO) potential energy for oxidation and glucose production (GP), we performed a lactate clamp (LC) procedure during rest and moderate intensity exercise. Blood [lactate] was clamped at ∼4 mM by exogenous lactate infusion. Subjects performed 90 min exercise trials at 65% of the peak rate of oxygen consumption (̇VO2,peak; 65%), 55% VO2,peak (55%) and 55% ̇VO2,peak with lactate clamped to the blood [lactate] that was measured at 65% VO2,peak (55%-LC). Lactate and glucose rates of appearance (Ra), disappearance (Rd) and oxidation (ROX) were measured with a combination of [3-13C]lactate, H13CO3-, and [6,6-2H2]glucose tracers. During rest and exercise, lactate Ra and Rd were increased at 55%-LC compared to 55%. Glucose Ra and Rd were decreased during 55%-LC compared to 55%. Lactate ROX was increased by LC during exercise (55%: 6.52 ± 0.65 and 55%-LC: 10.01 ± 0.68 mg kg-1 min-1) which was concurrent with a decrease in glucose oxidation (55%: 7.64 ± 0.4 and 55%-LC: 4.35 ± 0.31 mg kg-1 min-1). With LC, incorporation of 13C from tracer lactate into blood glucose (L → GNG) increased while both GP and calculated hepatic glycogenolysis (GLY) decreased. Therefore, increased blood [lactate] during moderate intensity exercise increased lactate oxidation, spared blood glucose and decreased glucose production. Further, exogenous lactate infusion did not affect rating of perceived exertion (RPE) during exercise. These results demonstrate that lactate is a useful carbohydrate in times of increased energy demand.
| Original language | English |
|---|---|
| Pages (from-to) | 963-975 |
| Number of pages | 13 |
| Journal | Journal of Physiology |
| Volume | 544 |
| Issue number | 3 |
| DOIs | |
| State | Published - Nov 1 2002 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physiology
Cite this
Lactate and glucose interactions during rest and exercise in men : Effect of exogenous lactate infusion. / Miller, Benjamin F.; Fattor, Jill A.; Jacobs, Kevin; Horning, Michael A.; Navazio, Franco; Lindinger, Michael I.; Brooks, George A.
In: Journal of Physiology, Vol. 544, No. 3, 01.11.2002, p. 963-975.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Lactate and glucose interactions during rest and exercise in men
T2 - Effect of exogenous lactate infusion
AU - Miller, Benjamin F.
AU - Fattor, Jill A.
AU - Jacobs, Kevin
AU - Horning, Michael A.
AU - Navazio, Franco
AU - Lindinger, Michael I.
AU - Brooks, George A.
PY - 2002/11/1
Y1 - 2002/11/1
N2 - To test the hypothesis that lactate plays a central role in the distribution of carbohydrate (CHO) potential energy for oxidation and glucose production (GP), we performed a lactate clamp (LC) procedure during rest and moderate intensity exercise. Blood [lactate] was clamped at ∼4 mM by exogenous lactate infusion. Subjects performed 90 min exercise trials at 65% of the peak rate of oxygen consumption (̇VO2,peak; 65%), 55% VO2,peak (55%) and 55% ̇VO2,peak with lactate clamped to the blood [lactate] that was measured at 65% VO2,peak (55%-LC). Lactate and glucose rates of appearance (Ra), disappearance (Rd) and oxidation (ROX) were measured with a combination of [3-13C]lactate, H13CO3-, and [6,6-2H2]glucose tracers. During rest and exercise, lactate Ra and Rd were increased at 55%-LC compared to 55%. Glucose Ra and Rd were decreased during 55%-LC compared to 55%. Lactate ROX was increased by LC during exercise (55%: 6.52 ± 0.65 and 55%-LC: 10.01 ± 0.68 mg kg-1 min-1) which was concurrent with a decrease in glucose oxidation (55%: 7.64 ± 0.4 and 55%-LC: 4.35 ± 0.31 mg kg-1 min-1). With LC, incorporation of 13C from tracer lactate into blood glucose (L → GNG) increased while both GP and calculated hepatic glycogenolysis (GLY) decreased. Therefore, increased blood [lactate] during moderate intensity exercise increased lactate oxidation, spared blood glucose and decreased glucose production. Further, exogenous lactate infusion did not affect rating of perceived exertion (RPE) during exercise. These results demonstrate that lactate is a useful carbohydrate in times of increased energy demand.
AB - To test the hypothesis that lactate plays a central role in the distribution of carbohydrate (CHO) potential energy for oxidation and glucose production (GP), we performed a lactate clamp (LC) procedure during rest and moderate intensity exercise. Blood [lactate] was clamped at ∼4 mM by exogenous lactate infusion. Subjects performed 90 min exercise trials at 65% of the peak rate of oxygen consumption (̇VO2,peak; 65%), 55% VO2,peak (55%) and 55% ̇VO2,peak with lactate clamped to the blood [lactate] that was measured at 65% VO2,peak (55%-LC). Lactate and glucose rates of appearance (Ra), disappearance (Rd) and oxidation (ROX) were measured with a combination of [3-13C]lactate, H13CO3-, and [6,6-2H2]glucose tracers. During rest and exercise, lactate Ra and Rd were increased at 55%-LC compared to 55%. Glucose Ra and Rd were decreased during 55%-LC compared to 55%. Lactate ROX was increased by LC during exercise (55%: 6.52 ± 0.65 and 55%-LC: 10.01 ± 0.68 mg kg-1 min-1) which was concurrent with a decrease in glucose oxidation (55%: 7.64 ± 0.4 and 55%-LC: 4.35 ± 0.31 mg kg-1 min-1). With LC, incorporation of 13C from tracer lactate into blood glucose (L → GNG) increased while both GP and calculated hepatic glycogenolysis (GLY) decreased. Therefore, increased blood [lactate] during moderate intensity exercise increased lactate oxidation, spared blood glucose and decreased glucose production. Further, exogenous lactate infusion did not affect rating of perceived exertion (RPE) during exercise. These results demonstrate that lactate is a useful carbohydrate in times of increased energy demand.
UR - http://www.scopus.com/inward/record.url?scp=0036850894&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036850894&partnerID=8YFLogxK
U2 - 10.1113/jphysiol.2002.027128
DO - 10.1113/jphysiol.2002.027128
M3 - Article
C2 - 12411539
AN - SCOPUS:0036850894
VL - 544
SP - 963
EP - 975
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 3
ER -