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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
70
The experimental procedure for each randomly assigned participant included a 4-week of KD diet.
The experimental procedure for each randomly assigned participant included a 4-week of CHO-LGI diet.
Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences
Poznan, Poland
Changes in aerobic capacity following dietary intervention
Time frame: 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)
Time frame: Baseline and after 4 weeks
Changes in energy substrates utilization following dietary intervention
Fats (g/min) and carbohydrates (g/min) oxidation analysis
Time frame: Baseline and after 4 weeks
Changes in fat mass and fat free mass following dietary intervention
Fat mass (kg) and fat free mass (kg) analysis
Time frame: 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
Time frame: 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
Time frame: Baseline and after 4 weeks
Changes in blood hematocrit levels following dietary intervention
Hematocrit (HCT) \[%\] level analysis
Time frame: Baseline and after 4 weeks
Changes of testosterone, cortisol, urea, lactate and pyruvate concentration in blood following dietary intervention
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Testosterone \[mmol/L\], cortisol \[mmol/L\], urea \[mmol/L\], lactate \[mmol/L\] and pyruvate \[mmol/L\] concentration analysis
Time frame: 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
Time frame: Baseline and after 4 weeks