Metabolic flexibility is unimpaired during exercise in the cold following acute glucose ingestion in young healthy adults
| Autor: | Stephanie Munten, Dominique D. Gagnon, Alexus McCue, Karl-Heinz Herzig |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Adult Male medicine.medical_specialty Flexibility (anatomy) Physiology 030310 physiology Glucose ingestion 010603 evolutionary biology 01 natural sciences Biochemistry 03 medical and health sciences Eating Young Adult Lipid oxidation Internal medicine medicine Ingestion Humans Lactic Acid Respiratory exchange ratio Exercise 0303 health sciences business.industry Temperature Calorimetry Indirect Metabolism Fasting Lipid Metabolism Healthy Volunteers Endocrinology medicine.anatomical_structure Glucose Adipose Tissue Exercise intensity Exercise Test Female Maximal exercise General Agricultural and Biological Sciences business Energy Metabolism Oxidation-Reduction Developmental Biology |
| Zdroj: | Journal of thermal biology. 98 |
| ISSN: | 0306-4565 |
| Popis: | Metabolic flexibility is compromised in individuals suffering from metabolic diseases, lipo- and glucotoxicity, and mitochondrial dysfunctions. Exercise studies performed in cold environments have demonstrated an increase in lipid utilization, which could lead to a compromised substrate competition, glycotoxic-lipotoxic state, or metabolic inflexibility. Whether metabolic flexibility is altered during incremental maximal exercise to volitional fatigue in a cold environment remains unclear.Ten young healthy participants performed four maximal incremental treadmill tests to volitional fatigue, in a fasted state, in a cold (0 °C) or a thermoneutral (22.0 °C) environment, with and without a pre-exercise ingestion of a 75-g glucose solution. Metabolic flexibility was assessed via indirect calorimetry using the change in respiratory exchange ratio (ΔRER), maximal fat oxidation (ΔMFO), and where MFO occurred along the exercise intensity spectrum (ΔFatMultiple linear mixed-effects regressions revealed an increase in glucose oxidation from glucose ingestion and an increase in lipid oxidation from the cold during exercise (p 0.001). No differences were observed in metabolic flexibility as assessed via ΔRER (0.05 ± 0.03 vs. 0.05 ± 0.03; p = 0.734), ΔMFO (0.21 ± 0.18 vs. 0.16 ± 0.13 g minFollowing glucose loading, metabolic flexibility was unaffected during exercise to volitional fatigue in a cold environment, inducing an increase in lipid oxidation. These results suggest that competing pathways responsible for the regulation of fuel selection during exercise and cold exposure may potentially be mechanistically independent. Whether long-term metabolic influences of high-fat diets and acute lipid overload in cold and warm environments would impact metabolic flexibility remain unclear. |
| Databáze: | OpenAIRE |
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