Effect of Ketogenic and Carbohydrate Diet in Crossfit

NCT03665948 | Active Not Recruiting

• 1 other identifier: ULS00004
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of the presented study was to assess the influence of Ketogenic (KD) and a carbohydrate diet with a low glycemic index (CHO-LGI) of a 4-week diet on physical and specific performance capacity, exercise metabolism, as well as concentrations of the selected biochemical blood markers in Crossfit- trained athletes, in a randomised and parallel trial.

Conditions

Nutrition; Ketogenic Dieting; Low Glycemic Index Diet; Sport; Crossfit

Keywords

Sports Nutrition; Ketogenic Diet; Low Glycemic Index Diet; Crossfit; Physical capacity; Performance; Exercise metabolism; Training support

Outcome Measures

Primary Outcomes (3)

• Changes in aerobic capacity following dietary intervention

  Baseline and after 4 weeks

• Changes in CrossFit-specific performance capacity (Fight Gone Bad test) following dietary intervention

  The number of correctly performed repetitions of exercises (reps)

  Baseline and after 4 weeks

• Changes in energy substrates utilization following dietary intervention

  Fats (g/min) and carbohydrates (g/min) oxidation analysis

  Baseline and after 4 weeks

Secondary Outcomes (6)

• Changes in fat mass and fat free mass following dietary intervention

  Baseline and after 4 weeks

• Changes of red and white blood cell concentration in blood following dietary intervention

  Baseline and after 4 weeks

• Changes in blood glucose and hemoglobin concentration following dietary intervention

  Baseline and after 4 weeks

• Changes in blood hematocrit levels following dietary intervention

  Baseline and after 4 weeks

• Changes of testosterone, cortisol, urea, lactate and pyruvate concentration in blood following dietary intervention

  Baseline and after 4 weeks

Study Arms (2)

Ketogenic Diet (KD)

EXPERIMENTAL

Group consuming very low carbohydrate ketogenic diet. The ketogenic diet model was energetically normalized (covered the estimated energy expenditure) and assumed coverage of the daily energy requirement up to 5% of energy from carbohydrates. Proteins were administered in the amount of 1.7 g per kilogram of body mass. The remaining energy needs were covered with fats (fats covered more than 75% of the daily energy requirement). Each of the subjects in this group received 10-day menus.

Other: Dietary Intervention - Ketogenic Diet (KD)

Low-Glycemic Index Diet (CHO-LGI)

ACTIVE COMPARATOR

Group consuming carbohydrate, low-glycemic index diet. The carbohydrate diet model with a low glycemic index was energetically normalized (covered the estimated energy expenditure) and assumed coverage of the daily energy requirement of 25% of fat. Proteins were administered in the amount of 1.7 g per kilogram of body mass. The remaining energy needs were covered with carbohydrates (carbohydrates covered about \~55% of the daily energy requirement). The glycemic index of individual meals as well as the daily diet was calculated in accordance with the appropriate recommendations. Each of the subjects in this group received 10-day menus.

Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)

Interventions

Dietary Intervention - Ketogenic Diet (KD) OTHER

The experimental procedure for each randomly assigned participant included a 4-week of KD diet.

Ketogenic Diet (KD)

Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI) OTHER

The experimental procedure for each randomly assigned participant included a 4-week of CHO-LGI diet.

Low-Glycemic Index Diet (CHO-LGI)

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• written consent to participate,
• a current medical clearance to practice sports,
• training experience: at least 2 years,
• minimum of 4 workout sessions (Crossfit) a week.

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 Physical Education: lead
• Poznan University of PhysED: collaborator
• Poznan University of Life Sciences: collaborator

Study Sites (1)

Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences

Poznan, 60-624, Poland

Location

Related Publications (1)

• Durkalec-Michalski K, Nowaczyk PM, Siedzik K. Effect of a four-week ketogenic diet on exercise metabolism in CrossFit-trained athletes. J Int Soc Sports Nutr. 2019 Apr 5;16(1):16. doi: 10.1186/s12970-019-0284-9.

  PMID: 30953522 DERIVED

Study Officials

• Jan Jeszka, Professor

  Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: September 5, 2018
• First Posted: September 11, 2018
• Study Start: January 9, 2017
• Primary Completion: November 1, 2024
• Study Completion: December 20, 2024
• Last Updated: May 16, 2024

Record last verified: 2024-05

Locations

PL (1)