Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

The influence of glucose ingestion on fuel utilization during prolonged exercise in children is currently unknown. The aim of this study was to determine what percentage of the total energy provision is covered by exogenous glucose (GLUexo) ingestion during prolonged exercise, in boys ages 12-16. Healthy untrained volunteers exercised for 120 min at 60% VO2max on a cycle ergometer while ingesting either water or a 13C-enriched GLUexo beverage (~3 g glucose/kg body mass). Total fat and carbohydrate utilization was determined from VO2 and respiratory exchange ratio. GLUexo oxidation was calculated from 13C/12C ratio in expired air. Compared with water intake, GLUexo intake increased carbohydrate utilization by 20% (203.1 ± 15.9 g/120-min vs 169.1 ± 12.9, P < 0.01) and lowered fatty acid utilization by 45% (17.1 ± 2.5 g/120-min vs. 31.0 ± 4.2 g/120-min, P < 0.01). The total amount of GLUexo oxidized was 57.8 ± 4.3 g or 34.2 ± 2.2 % of that ingested. Compared with water intake, GLUexo intake lowered endogenous glucose utilization by 16 % (145.3 ± 11.9 g/120min vs. 169.1 ± 12.9 g/120-min, P < 0.01). In conclusion, GLUexo intake spares endogenous carbohydrate and contributes to approximately 25% of the total energy demand of prolonged moderate exercise. Supported by, Gatorade Sports Science Institute

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Poster Number PAriddell0623
Keywords: exercise, glucose, stable isotopes, children, carbohydrate