Endurance training on low-carbohydrate and grain-based diets: a case study.
OBJECTIVE
To illustrate the effects of low-carbohydrate (LC) and grain-based (GB) diets on body composition, biomarkers, athletic training, and performance in an elite triathlete.


METHODS
The athlete followed 2 dietary interventions for 14 d while maintaining a prescheduled training program. Pre- and postintervention measurements for each diet included plasma and serum samples, resting energy expenditure, body composition, and a performance bike ride.


RESULTS
Compared with the GB diet, the LC diet elicited more disruptions to training and unfavorable subjective experiences. Total cholesterol, HDL cholesterol, LDL cholesterol, ratings of perceived exertion, and heart rate were elevated on the LC diet. Blood insulin, resting lactate, postexercise lactate, and C-reactive protein were lowest on the LC diet.


CONCLUSIONS
The LC diet resulted in both favorable and unfavorable outcomes. The primary observation was a disruption to scheduled training on the LC diet. Researchers should consider how the potential mediating effect of disruptions to training could influence pretest-posttest designs.
Rosenkranz
Richard R
RR
Human Nutrition Dept, Kansas State University, Manhattan, KS 66506, USA.
Cook
Chad M
CM
Haub
Mark D
MD
D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D002097:C-Reactive Protein / Q000032:analysis; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D002523:Edible Grain; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*
D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D007328:Insulin; D019344:Lactic Acid; D002097:C-Reactive Protein; D002784:Cholesterol