Effect of Ketogenic and Carbohydrate Diet in Crossfit
- Conditions
- Ketogenic DietingLow Glycemic Index DietNutritionSportCrossfit
- Interventions
- Other: Dietary Intervention - Low-Glycemic Index Diet (CHO-LGI)Other: Dietary Intervention - Ketogenic Diet (KD)
- Registration Number
- NCT03665948
- Lead Sponsor
- Poznan University of Physical Education
- 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.
Recruitment & Eligibility
- Status
- ACTIVE_NOT_RECRUITING
- Sex
- All
- Target Recruitment
- 70
- 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.
- 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.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Low-Glycemic Index Diet (CHO-LGI) Dietary Intervention - 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. Ketogenic Diet (KD) Dietary Intervention - 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.
- Primary Outcome Measures
Name Time Method Changes in energy substrates utilization following dietary intervention Baseline and after 4 weeks Fats (g/min) and carbohydrates (g/min) oxidation analysis
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 Baseline and after 4 weeks The number of correctly performed repetitions of exercises (reps)
- Secondary Outcome Measures
Name Time Method Changes in blood glucose and hemoglobin concentration following dietary intervention Baseline and after 4 weeks Hemoglobin (Hb) \[g/dl\] and glucose \[g/dl\] concentration analysis
Changes of testosterone, cortisol, urea, lactate and pyruvate concentration in blood following dietary intervention Baseline and after 4 weeks Testosterone \[mmol/L\], cortisol \[mmol/L\], urea \[mmol/L\], lactate \[mmol/L\] and pyruvate \[mmol/L\] concentration analysis
Changes in fat mass and fat free mass following dietary intervention Baseline and after 4 weeks Fat mass (kg) and fat free mass (kg) analysis
Changes of red and white blood cell concentration in blood following dietary intervention Baseline and after 4 weeks Red blood cells (RBC) \[mln/mm³\] and white blood cells (WBC) \[mln/mm³\] concentration analysis
Changes in blood hematocrit levels following dietary intervention Baseline and after 4 weeks Hematocrit (HCT) \[%\] level analysis
Changes of creatine kinase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase activity in blood after following dietary intervention Baseline and after 4 weeks Creatine kinase \[U/L\], lactate dehydrogenase \[U/L\], alanine aminotransferase \[U/L\] and aspartate aminotransferase \[U/L\] activity analysis
Trial Locations
- Locations (1)
Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences
🇵🇱Poznań, Poland