The Effect of Diet Composition on Performance, Expenditure, Blood Lipids, and Appetite Hormones in Highly Trained Cyclists (DCAP)

Texas Christian University

Status: Completed

Conditions: Endurance Cycling Performance

Treatments: Other: Diet

Study type: Interventional

Funder types: Other

Identifiers

NCT04097171

CT2019MS3

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 34 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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34 participants in 2 patient groups

High Carbohydrate Diet

Experimental group

Description:

Participants will consume a high carbohydrate diet (65-75% of total energy intake). Protein intake will be standardized at 15% of total energy intake.

Treatment:

Other: Diet

Ketogenic Diet

Experimental group

Description:

Participants will consume a low carbohydrate diet (\<5-10% of total energy intake). Protein intake will be standardized at 15% of total energy intake.

Treatment:

Other: Diet