The Effect of Diet Composition on Performance, Expenditure, Blood Lipids, and Appetite Hormones in Highly Trained Cyclists
The Effect of Diet Composition on Performance, Expenditure, Blood Lipids, and Appetite Hormones in Highly Trained Cyclists
This study employs a crossover design to evaluate the effect of two different diets (high
 carbohydrate vs. ketogenic) and corresponding test meals on endurance exercise performance,
 energy expenditure including resting metabolic rate and thermic effect of food, postprandial
 responses of blood lipids, glucose and appetite hormones, and cognitive function and mood
 states.
Traditionally, a high carbohydrate diet is recommended for elite endurance athletes and
 sub-elite, highly trained recreational athletes competing in endurance events. However,
 recently the ketogenic diet (extremely low carbohydrate content) has become popular in these
 populations. The effect on endurance exercise performance, energy expenditure, postprandial
 blood profiles, and cognitive function and mood states requires further investigation.

 In this study, highly trained recreational cyclists and triathletes will adhere to each diet
 (high-carbohydrate and ketogenic) for 14 days in a crossover design. Experimental trials at
 baseline and after each diet will evaluate endurance cycling performance (time trial),
 resting energy expenditure, the thermic effect of food of test meals corresponding in
 composition to each diet, postprandial responses of blood lipids, glucose and appetite
 hormones, and cognitive function and mood states.
Inclusion Criteria:

 -  >100-150km of cycling per week

 -  VO2max > 80th percentile for sex and age (adjusted for cycle ergometry)

 -  apparently healthy

 Exclusion Criteria:

 -  weight loss supplements/medications/diet

 -  extreme dietary patterns (e.g. extremely high or low carbohydrate)

 -  nicotine use

 -  heavy alcohol use (>7 drinks/week female; >14 drinks/week male)

 -  food allergies

 -  diabetes

 -  heart disease

 -  stroke

 -  liver/kidney/thyroid disease

 -  anemia

 -  eating disorders

 -  uncontrolled hypertension

 -  pulmonary/orthopedic/musculoskeletal problems that prevent exercise

 -  surgery that affects swallowing and digestion

 -  claustrophobia