Effect of Glycemic Index on Physical Capacity in Runners

NCT03062527 | Completed

• 1 other identifier: ULS00001
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

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.

Conditions

Nutrition; Sport; Glycemic Index; Physical Capacity

Keywords

Nutrition; Training support; Low Glycemic Index; Moderate Glycemic Index; Endurance; Running

Outcome Measures

Primary Outcomes (6)

• Changes in aerobic capacity following low glycemic index diet

  Baseline and after 3 weeks

• Changes in aerobic capacity 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 performance in 12-min running test following moderate glycemic index diet

  Baseline and after 3 weeks

• Changes in fat mass and fat free mass following low glycemic index diet

  Fat mass (kg) and fat free mass (kg) analysis

  Baseline and after 3 weeks

• Changes in fat mass and fat free mass following moderate glycemic index diet

  Fat mass (kg) and fat free mass (kg) analysis

  Baseline and after 3 weeks

Secondary Outcomes (3)

• 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 performance in 12-min running test

  1 year

• Statistical evaluation of the significance of differences between the changes in fat mass and fat free mass

  1 year

Study Arms (2)

Low Glycemic Index Diet

EXPERIMENTAL

Group consuming low glycemic index diet. Calculated glycemic index of daily diet was lower than 40. Carbohydrate- containing foods included whole rye bread, pumpernickel bread, whole oats, wheat brans, brown rice, buckwheat, vegetables (besides corn, cooked carrots, potatoes and pumpkin) and fruit such as apples, pears, grapefruits, tangerines, prunes, dried apricots and unripe bananas. Interventions: The experimental procedure for each participant included a 3-week low glycemic index diet. Between the 3-week low and moderate glycemic index diets or a moderate and low glycemic index treatment, a 14-day washout period was introduced.

Other: Dietary Intervention: Low vs. moderate glycemic index

Moderate Glycemic Index Diet

EXPERIMENTAL

Group consuming moderate glycemic index diet. Calculated glycemic index of diet was higher than 60. Carbohydrate- containing foods included wheat bread, wheat rolls, potatoes, instant oats, cornflakes, white rice, millet, boiled carrots and fruit (ripe bananas, grapes, raisins, dates, cranberry, honey and high sugar jams) Interventions: The experimental procedure for each participant included a 3-week moderate glycemic index diet. Between the 3-week low and moderate glycemic index diets or a moderate and low glycemic index treatment, a 14-day washout period was introduced.

Other: Dietary Intervention: Low vs. moderate glycemic index

Interventions

Dietary Intervention: Low vs. moderate glycemic index OTHER

Low Glycemic Index Diet; Moderate Glycemic Index Diet

Eligibility Criteria

• Age: 17 Years - 37 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Poznan University of Life Sciences: lead

Study Sites (1)

Poznan University of Life Sciences, ul.Wojska Polskiego 31

Poznan, Wielkopolska, 60-624, Poland

Location

Study Officials

• Jan Jeszka, Professor

  Department of Hygiene and Human Nutrition, Poznan University of Life Sciences, Poznan, Poland

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: February 14, 2017
• First Posted: February 23, 2017
• Study Start: January 1, 2015
• Primary Completion: February 6, 2015
• Study Completion: May 1, 2015
• Last Updated: February 23, 2017

Record last verified: 2017-02

Locations

PL (1)