Metabolic characteristics of keto-adapted ultra-endurance runners
| Autor: | Jeffrey M. Anderson, Laura J. Kunces, Giselle A. Aerni, Mark D. Schuenke, Elaine C. Lee, Jenna M. Bartley, Daniel J. Freidenreich, William J. Kraemer, Catherine Saenz, Carl M. Maresh, Jeff S. Volek, Brent C. Creighton, Stephen D. Phinney, Colleen X. Muñoz, Patrick M. Davitt |
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| Rok vydání: | 2015 |
| Předmět: |
Adult
Male medicine.medical_specialty Anaerobic Threshold Endocrinology Diabetes and Metabolism 030209 endocrinology & metabolism Running 03 medical and health sciences chemistry.chemical_compound Diet Carbohydrate-Restricted Young Adult 0302 clinical medicine NEFA Endocrinology Internal medicine medicine Dietary Carbohydrates Humans Treadmill Muscle Skeletal Respiratory exchange ratio Glycogen Urine specific gravity VO2 max 030229 sport sciences Carbohydrate Middle Aged Adaptation Physiological Dietary Fats Cross-Sectional Studies chemistry Exercise Test Physical Endurance Anaerobic exercise Oxidation-Reduction |
| Zdroj: | Metabolism: clinical and experimental. 65(3) |
| ISSN: | 1532-8600 |
| Popis: | Background Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. Methods Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180min submaximal run at 64% VO 2 max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n=10 , %carbohydrate:protein:fat=59:14:25) diet, and the other a low-carbohydrate (LC; n=10 , 10:19:70) diet for an average of 20months (range 9 to 36months). Results Peak fat oxidation was 2.3-fold higher in the LC group (1.54±0.18 vs 0.67±0.14g/min; P=0.000 ) and it occurred at a higher percentage of VO 2 max (70.3±6.3 vs 54.9±7.8%; P=0.000 ). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21±0.02 vs 0.76±0.11g/min; P=0.000 ) corresponding to a greater relative contribution of fat (88±2 vs 56±8%; P=0.000 ). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180min of running (−64% from pre-exercise) and 120min of recovery (−36% from pre-exercise). Conclusion Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3hour run are similar. |
| Databáze: | OpenAIRE |
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