International Journal of Sport Nutrition and Exercise Metabolism · 2005 · 29 citations · 49 references
Life SciencesNutritional SciencesPhysiologyExercise PhysiologyMetabolic PhysiologyNutritional PhysiologyAerobic CapacityAerobic ExerciseCarbohydrate MetabolismEndurance PerformanceMetabolic Adaptation To ExerciseMetabolic Responses To ExerciseBlood Glucose RegulationCarbohydrate Ingestion During ExerciseEnduranceEndurance Exercise MetabolismExercise Energy MetabolismLow-carbohydrate DietsMetabolic Adaptation To TrainingMuscle Glycogen Metabolism
The impact of altered blood glucose concentrations on exercise metabolism and performance after a low carbohydrate (CHO) diet was investigated. In random order, 1 wk apart, 9 trained men underwent euglycemic (CI) or placebo (PI) clamps, while performing up to 150 min of cycling at 70% VO2(max), after 48 h on a low CHO diet. The range in improvement in endurance capacity with glucose infusion was large (28 +/- 26%, P < 0.05). Fifty-six percent of subjects in CI failed to complete 150 min of exercise despite maintenance of euglycemia, while only 2 subjects in PI completed 150 min of exercise, despite being hypoglycemic. Total CHO oxidation remained similar between trials. Despite longer exercise times in CI, similar amounts of muscle glycogen were used to PI. Maintenance of euglycemia in the CHO-depleted state might have an ergogenic effect, however, the effect is highly variable between individuals and independent of changes in CHO oxidation.
49
A new validated endurance performance test
Asker E. Jeukendrup, Wim H. M. Saris, Fred Brouns et al. · Medicine & Science in Sports & Exercise · 1996 · 557 citations · Full text