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NutritionNCT03665948

Effect of Ketogenic and Carbohydrate Diet in Crossfit

A study testing Dietary Intervention - Ketogenic Diet (KD) and Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI) in people with Nutrition and Ketogenic Dieting, run by Poznan University of Physical Education at 1 site in Poland.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial 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… Read more about this study

Who is it for?
Ages 18 to 40 yearsHealthy volunteers can take part
What is being tested?
Dietary Intervention - Ketogenic Diet (KD) and Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
70 participants
Where
1 sitePoland
Study dates
9 Jan 2017to 20 Dec 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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.

Who cannot join

  • 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 locations and contacts

1 site in 1 country.

Poland1 site

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

    Poznan, 60-624

Other trials in Poland

About this study

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

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.

Read the 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.

Being tested
Dietary Intervention - Ketogenic Diet (KD), Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)
Keywords
Sports Nutrition, Ketogenic Diet, Low Glycemic Index Diet, Crossfit, Physical capacity, Performance, Exercise metabolism, Training support

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Dietary Intervention - Ketogenic Diet (KD)Other

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

  • 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.

Study groups in NCT03665948
Study groupRoleWhat they receive
Ketogenic Diet (KD)ExperimentalGroup 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.
Receives: Other: Dietary Intervention - Ketogenic Diet (KD)
Low-Glycemic Index Diet (CHO-LGI)Active comparatorGroup 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.
Receives: Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in aerobic capacity following dietary intervention

    Measured: Baseline and after 4 weeks

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

    The number of correctly performed repetitions of exercises (reps)

    Measured: Baseline and after 4 weeks

  3. Changes in energy substrates utilization following dietary intervention

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

    Measured: Baseline and after 4 weeks

Secondary outcomes (6)

  1. Changes in fat mass and fat free mass following dietary intervention

    Fat mass (kg) and fat free mass (kg) analysis

    Measured: Baseline and after 4 weeks

  2. 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

    Measured: Baseline and after 4 weeks

  3. Changes in blood glucose and hemoglobin concentration following dietary intervention

    Hemoglobin (Hb) [g/dl] and glucose [g/dl] concentration analysis

    Measured: Baseline and after 4 weeks

  4. Changes in blood hematocrit levels following dietary intervention

    Hematocrit (HCT) [%] level analysis

    Measured: Baseline and after 4 weeks

  5. 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

    Measured: Baseline and after 4 weeks

  6. 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

    Measured: Baseline and after 4 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Sep 2018
  2. Study start9 Jan 2017
  3. Primary completion1 Nov 2024 (estimated)
  4. Study completion20 Dec 2024 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
70 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03665948
Sponsor's protocol ID
ULS00004
Status last verified
May 2024
First submitted
5 Sep 2018
Last updated
16 May 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: 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.

Publications

  • 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.

    PubMed 30953522

Questions about this trial

What is this clinical trial studying?

A study testing Dietary Intervention - Ketogenic Diet (KD) and Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI) in people with Nutrition and Ketogenic Dieting, run by Poznan University of Physical Education at 1 site in Poland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 16 May 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in aerobic capacity following dietary intervention (time frame: Baseline and after 4 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03665948, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 May 2024.

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