Effect of Ketogenic and Carbohydrate Diet in Crossfit

Poznan University of Physical Education

Status: Active, not recruiting

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

Treatments: Other: Dietary Intervention - Ketogenic Diet (KD); Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)

Study type: Interventional

Funder types: Other

Identifiers

NCT03665948

ULS00004

Details and patient eligibility

About

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.

Full 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.

Enrollment: 70 estimated patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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70 participants in 2 patient groups

Ketogenic Diet (KD)

Experimental group

Description:

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.

Treatment:

Other: Dietary Intervention - Ketogenic Diet (KD)

Low-Glycemic Index Diet (CHO-LGI)

Active Comparator group

Description:

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.

Treatment:

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