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Effect of Ketogenic and Carbohydrate Diet in Crossfit

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ClinicalTrials.gov Identifier: NCT03665948
Recruitment Status : Recruiting
First Posted : September 11, 2018
Last Update Posted : April 2, 2019
Sponsor:
Collaborator:
Poznan University of Physical Education
Information provided by (Responsible Party):
Krzysztof Durkalec-Michalski, PhD, Poznan University of Life Sciences

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.

Condition or disease Intervention/treatment Phase
Nutrition Ketogenic Dieting Low Glycemic Index Diet Sport Crossfit Other: Dietary Intervention - Ketogenic Diet (KD) Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI) Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 70 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
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
Actual Study Start Date : January 9, 2017
Estimated Primary Completion Date : November 1, 2020
Estimated Study Completion Date : December 20, 2020

Arm Intervention/treatment
Experimental: 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.
Other: Dietary Intervention - Ketogenic Diet (KD)
The experimental procedure for each randomly assigned participant included a 4-week of KD diet.

Active Comparator: 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.
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.




Primary Outcome Measures :
  1. Changes in aerobic capacity following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
  2. Changes in CrossFit-specific performance capacity (Fight Gone Bad test) following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    The number of correctly performed repetitions of exercises (reps)

  3. Changes in energy substrates utilization following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Fats (g/min) and carbohydrates (g/min) oxidation analysis


Secondary Outcome Measures :
  1. Changes in fat mass and fat free mass following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Fat mass (kg) and fat free mass (kg) analysis

  2. Changes of red and white blood cell concentration in blood following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Red blood cells (RBC) [mln/mm³] and white blood cells (WBC) [mln/mm³] concentration analysis

  3. Changes in blood glucose and hemoglobin concentration following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Hemoglobin (Hb) [g/dl] and glucose [g/dl] concentration analysis

  4. Changes in blood hematocrit levels following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Hematocrit (HCT) [%] level analysis

  5. Changes of testosterone, cortisol, urea, lactate and pyruvate concentration in blood following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Testosterone [mmol/L], cortisol [mmol/L], urea [mmol/L], lactate [mmol/L] and pyruvate [mmol/L] concentration analysis

  6. Changes of creatine kinase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase activity in blood after following dietary intervention [ Time Frame: Baseline and after 4 weeks ]
    Creatine kinase [U/L], lactate dehydrogenase [U/L], alanine aminotransferase [U/L] and aspartate aminotransferase [U/L] activity analysis



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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03665948


Contacts
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Contact: Krzysztof Durkalec-Michalski, PhD +48 618 487 338 durkmich@up.poznan.pl

Locations
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Poland
Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences Recruiting
Poznań, Poland, 60-624
Contact: Krzysztof Durkalec-Michalski, PhD    +48 618 487 338    durkmich@up.poznan.pl   
Sponsors and Collaborators
Poznan University of Life Sciences
Poznan University of Physical Education
Investigators
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Study Chair: Jan Jeszka, Professor Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Krzysztof Durkalec-Michalski, PhD, Assistant Professor, Poznan University of Life Sciences
ClinicalTrials.gov Identifier: NCT03665948     History of Changes
Other Study ID Numbers: ULS00004
First Posted: September 11, 2018    Key Record Dates
Last Update Posted: April 2, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided
Plan Description: Shared data will be exclusively related to the level recorded indicators (anaerobic capacity and specific performance capacity indicators, exercise metabolism, levels of biochemical markers, and body composition), without personal data. The data obtained will be attached to scientific publications, depending on the requirements of the journal.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Krzysztof Durkalec-Michalski, PhD, Poznan University of Life Sciences:
Sports Nutrition
Ketogenic Diet
Low Glycemic Index Diet
Crossfit
Physical capacity
Performance
Exercise metabolism
Training support