Clinical trial NCT03062527: Effect of Glycemic Index on Physical Capacity in Runners
Official title: Effects of Low and Versus Moderate Glycemic Index Diets on Physical Capacity and Body Composition in Endurance- Trained Runners
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Nutrition
Sport
Glycemic Index
Physical Capacity
Keywords: Nutrition
Training support
Low Glycemic Index
Moderate Glycemic Index
Endurance
Running
Lead sponsor: Poznan University of Life Sciences
Sponsor class: OTHER
First posted: 2017-02-23
Enrollment: 36
Sex: ALL
Minimum age (years): 17
Maximum age (years): 37
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Changes in aerobic capacity following low glycemic index diet
timeFrame: Baseline and after 3 weeks
measure: Changes in aerobic capacity following moderate glycemic index diet
timeFrame: Baseline and after 3 weeks
measure: Changes in performance in 12-min running test following low glycemic index diet
timeFrame: Baseline and after 3 weeks
measure: Changes in performance in 12-min running test following moderate glycemic index diet
timeFrame: Baseline and after 3 weeks
measure: Changes in fat mass and fat free mass following low glycemic index diet
timeFrame: Baseline and after 3 weeks
measure: Changes in fat mass and fat free mass following moderate glycemic index diet
timeFrame: Baseline and after 3 weeks
Secondary outcomes:
measure: Statistical evaluation of the significance of differences between the changes in aerobic capacity indices
timeFrame: 1 year
measure: Statistical evaluation of the significance of differences between the changes in performance in 12-min running test
timeFrame: 1 year
measure: Statistical evaluation of the significance of differences between the changes in fat mass and fat free mass
timeFrame: 1 year
Other outcomes:
Locations:
city: Poznan
country: Poland
facility: Poznan University of Life Sciences, ul.Wojska Polskiego 31
state: Wielkopolska
Study officials:
affiliation: Department of Hygiene and Human Nutrition, Poznan University of Life Sciences, Poznan, Poland
name: Jan Jeszka, Professor
role: STUDY_CHAIR
References: