Effect of Glycemic Index on Physical Capacity in Runners

Effects of Low and Versus Moderate Glycemic Index Diets on Physical Capacity and Body Composition in Endurance- Trained Runners

The purpose of the present study was to assess the influence of low vs moderate glycemic index of a 3-week diet on aerobic capacity, endurance performance and body mass and composition in endurance-trained athletes in a randomized, controlled crossover trial.

The effect of glycemic index of pre-exercise meal on endurance capacity and performance has been widely investigated. However, little is known about the adaptations to longer dietary interventions with different glycemic index and their influence on aerobic capacity and body composition in runners. Therefore, the purpose of this study was the assessment of the influence of low GI vs moderate GI of a 3-week diet on aerobic capacity, endurance performance and body mass and composition in endurance-trained athletes in a randomised, controlled crossover trial.

Inclusion Criteria:

• written consent to participate,
• male and female,
• a current medical clearance to practice sports,
• training experience: at least 3 years,
• minimum of 4 workout sessions a week lasting at least 1.5-2 hours/day,
• age: 17 - 37 years.

Exclusion Criteria:

• current injury,
• any health-related contraindication,
• declared general feeling of being unwell,
• unwilling to follow the study protocol,
• smoking, illicit drug use, alcohol consumption greater than 1-2 drinks/week, dietary supplements use less than 3 weeks before the study,
• females- being pregnant or planning to become pregnant during the study.