Effect of Glycemic Index on Physical Capacity in Runners

Not Applicable

Completed

• Conditions: Nutrition; Physical Capacity; Sport; Glycemic Index

• Registration Number: NCT03062527
• Lead Sponsor: Poznan University of Life Sciences

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Study Start: 2015-01
• Primary Completion: 2015-02-06
• Study Completion: 2015-05-01
• Status Verified: 2017-02
• Study First Submitted: 2017-02-14
• Study First Submitted QC: 2017-02-20
• Last Update Submitted: 2017-02-20
• Study First Posted: 2017-02-23
• Last Update Posted: 2017-02-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 36

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Changes in aerobic capacity following moderate glycemic index diet	Baseline and after 3 weeks
Changes in aerobic capacity following low glycemic index diet	Baseline and after 3 weeks
Changes in performance in 12-min running test following moderate glycemic index diet	Baseline and after 3 weeks
Changes in performance in 12-min running test following low glycemic index diet	Baseline and after 3 weeks
Changes in fat mass and fat free mass following low glycemic index diet	Baseline and after 3 weeks	Fat mass (kg) and fat free mass (kg) analysis
Changes in fat mass and fat free mass following moderate glycemic index diet	Baseline and after 3 weeks	Fat mass (kg) and fat free mass (kg) analysis

Secondary Outcome Measures

Name	Time	Method
Statistical evaluation of the significance of differences between the changes in aerobic capacity indices	1 year
Statistical evaluation of the significance of differences between the changes in fat mass and fat free mass	1 year	Fat mass (kg) and fat free mass (kg)
Statistical evaluation of the significance of differences between the changes in performance in 12-min running test	1 year

Trial Locations

Locations (1)

Poznan University of Life Sciences, ul.Wojska Polskiego 31; 🇵🇱 Poznan, Wielkopolska, Poland