Effect of Ketogenic and Carbohydrate Diet in Crossfit

Study Overview
=================
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.

Official Title
-----------------
The Effect of Ketogenic and Carbohydrate, Low-Glycemic Index Diet on Physical and Specific Performance Capacity, and Exercise Metabolism in Crossfit- Trained Athletes

Conditions
-----------------
Nutrition, Ketogenic Dieting, Low Glycemic Index Diet, Sport, Crossfit

Intervention / Treatment
-----------------
* Other: Dietary Intervention - Ketogenic Diet (KD)
* Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)


Participation Criteria
=================
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.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ketogenic Diet (KD)<br>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)<br>* The experimental procedure for each randomly assigned participant included a 4-week of KD diet.<br>|
| Active Comparator: Low-Glycemic Index Diet (CHO-LGI)<br>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)<br>* The experimental procedure for each randomly assigned participant included a 4-week of CHO-LGI diet.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in fat mass and fat free mass following dietary intervention | Fat mass (kg) and fat free mass (kg) analysis | Baseline and after 4 weeks | 
| Changes of red and white blood cell concentration in blood following dietary intervention | Red blood cells (RBC) [mln/mm³] and white blood cells (WBC) [mln/mm³] concentration analysis | Baseline and after 4 weeks | 
| Changes in blood glucose and hemoglobin concentration following dietary intervention | Hemoglobin (Hb) [g/dl] and glucose [g/dl] concentration analysis | Baseline and after 4 weeks | 
| Changes in blood hematocrit levels following dietary intervention | Hematocrit (HCT) [%] level analysis | Baseline and after 4 weeks | 
| Changes of testosterone, cortisol, urea, lactate and pyruvate concentration in blood following dietary intervention | Testosterone [mmol/L], cortisol [mmol/L], urea [mmol/L], lactate [mmol/L] and pyruvate [mmol/L] concentration analysis | Baseline and after 4 weeks | 
| Changes of creatine kinase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase activity in blood after following dietary intervention | Creatine kinase [U/L], lactate dehydrogenase [U/L], alanine aminotransferase [U/L] and aspartate aminotransferase [U/L] activity analysis | Baseline and after 4 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Sports Nutrition, Ketogenic Diet, Low Glycemic Index Diet, Crossfit, Physical capacity, Performance, Exercise metabolism, Training support