Effect of Ketogenic and Carbohydrate Diet in Crossfit

NCT ID: NCT03665948

Last Updated: 2024-05-16

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 70 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-01-09
• Study Completion Date: 2024-12-20

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.

Detailed Description

The impact of various dietary strategies, including the alternative ketogenic diet - recently popular among strength athletes, has not been unequivocally assessed in the high-intensity sport disciplines that Crossfit belongs to. There is also a lack of data in these disciplines about the potential longer adaptation of athletes to the very low carbohydrate intake resulting from the ketogenic diet and its impact in high-intensity Crossfit training. Therefore, the purpose of this study was the assessment of the influence of a 4-week KD and a CHO-LGI 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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Ketogenic Diet (KD)

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.

Group Type: EXPERIMENTAL

Dietary Intervention - Ketogenic Diet (KD)

Intervention Type: OTHER

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

Low-Glycemic Index Diet (CHO-LGI)

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.

Group Type: ACTIVE_COMPARATOR

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

Intervention Type: OTHER

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

Interventions

Dietary Intervention - Ketogenic Diet (KD)

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

Intervention Type: OTHER

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

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

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• 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.

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Poznan University of PhysED

INDIV

Sponsor Role: collaborator

Poznan University of Life Sciences

OTHER

Sponsor Role: collaborator

Poznan University of Physical Education

OTHER

Sponsor Role: lead

Responsible Party

Krzysztof Durkalec-Michalski

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jan Jeszka, Professor

Role: STUDY_CHAIR

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

Locations

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

Poznan, , Poland

Countries

Poland

References

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.

Reference Type: DERIVED

PMID: 30953522 (View on PubMed)

Other Identifiers

ULS00004

Identifier Type: -

Identifier Source: org_study_id