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Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
Published on: March 15, 2019
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Exogenous glucose oxidation during endurance exercise in hypoxia.
Daichi Sumi1,2, Nanako Hayashi1, Haruka Yatsutani1
1Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.
Physiological Reports
|July 12, 2020
Summary
Endurance exercise in moderate hypoxia, at the same absolute intensity, increases lactate and respiratory exchange ratio but reduces exogenous glucose oxidation. This indicates altered carbohydrate metabolism during hypoxic exercise.
Area of Science:
- Exercise Physiology
- Sports Science
- Human Metabolism
Background:
- Endurance exercise significantly impacts carbohydrate metabolism.
- Hypoxia, a condition of reduced oxygen availability, is known to influence metabolic responses during exercise.
- Detailed understanding of exogenous glucose utilization during exercise in hypoxia is limited.
Purpose of the Study:
- To investigate the effects of moderate hypoxia on exogenous glucose oxidation during endurance exercise.
- To compare glucose metabolism at the same absolute exercise intensity and relative exercise intensity in normoxia versus hypoxia.
Main Methods:
- Nine healthy males performed 30-minute running trials at 65% of normoxic maximal oxygen uptake in normoxia (NOR), relative hypoxia (HYPR), and absolute intensity hypoxia (HYPA).
- Subjects ingested 13C-labeled glucose before exercise.
- Expired gas was collected to measure 13C-excretion, indicating exogenous glucose oxidation.
Main Results:
- Exercise-induced blood lactate and respiratory exchange ratio (RER) were significantly higher in HYPA compared to NOR and HYPR.
- Exogenous glucose oxidation was significantly lower in HYPA compared to NOR.
- No significant differences in lactate, RER, or glucose oxidation were found between NOR and HYPR.
Conclusions:
- Moderate hypoxia during endurance exercise at the same absolute intensity elevates blood lactate and RER.
- Exogenous glucose oxidation is attenuated during endurance exercise in moderate hypoxia at the same absolute intensity compared to normoxia.
- Hypoxic exercise at the same relative intensity does not significantly alter these metabolic markers compared to normoxic exercise.
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