Effects of Different Caffeine Ingestion Forms on Fat Oxidation During Cycle Ergometer Exercise
Overview
- Phase
- Not Applicable
- Status
- Enrolling By Invitation
- Sponsor
- Universidad Rey Juan Carlos
- Enrollment
- 10
- Locations
- 1
- Primary Endpoint
- Rate of fat oxidation during submaximal cycling exercise at Fatmax intensity
Overview
Brief Summary
The goal of this clinical trial is to learn if different forms of caffeine ingestion can influence fat oxidation during submaximal cycling exercise. The study will recruit healthy adults, both men and women, aged 18 to 50, who regularly perform aerobic exercise. The main questions it aims to answer are:
- Does caffeine increase fat oxidation during one hour of cycling at the Fatmax intensity?
- Do different forms of caffeine ingestion (capsule, coffee, chewing gum, or mouth rinse) differ in their effect on fat oxidation?
- Do these caffeine forms alter total energy expenditure, cardiorespiratory response, or perceived exertion during exercise?
- Are there differences in the occurrence or severity of side effects between caffeine administration methods?
Researchers will compare each caffeine form to its corresponding placebo to determine their effects on fat oxidation and other physiological outcomes.
Participants will:
- Attend a pre-experimental session to determine their Fatmax intensity and VO₂max using an incremental cycling test
- Perform eight experimental sessions, each consisting of one hour of cycling at Fatmax intensity
- Receive caffeine or placebo via capsules, coffee, chewing gum, or mouth rinse according to a randomized, double-blind, crossover design
- Be monitored for fat and carbohydrate oxidation, total energy expenditure, heart rate, and perceived exertion during exercise
- Report any side effects immediately after the session and 24 hours later using a structured questionnaire
All sessions will be conducted under controlled laboratory conditions with standardized protocols to ensure safety and reliable measurements.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Double (Participant, Investigator)
Eligibility Criteria
- Ages
- 18 Years to 50 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Healthy men and women aged 18-50 years
- •Regular aerobic exercise at least 1 hour per day, 2 days per week
- •Provide written informed consent
Exclusion Criteria
- •Use of medication or ergogenic supplements during the study period
- •Caffeine intolerance or allergy
- •Cardiopulmonary or musculoskeletal disorders
- •Use of oral contraceptives in female participants
Arms & Interventions
Placebo capsule
Participants will ingest an opaque capsule filled with cellulose (placebo) 60 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Placebo (Cellulose Capsule) (Other)
Caffeine coffee
Participants will consume 3 mg/kg of caffeine via soluble coffee (Nescafé Classic) in 250 mL of hot water 60 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Caffeine (Nescafé Classic Coffee) (Dietary Supplement)
Placebo coffee
Participants will consume decaffeinated soluble coffee (Nescafé Descafeinado) in 250 mL of hot water 60 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Placebo (Decaffeinated Coffee) (Other)
Caffeine chewing gum
Participants will chew caffeinated gum (Kafewake) containing 3 mg/kg of caffeine for 10 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Caffeine (Kafewake Gum) (Dietary Supplement)
Placebo chewing gum
Participants will chew non-caffeinated gum (Kafewake) with identical flavor and texture for 10 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Placebo (Non-caffeine Gum) (Other)
Caffeine mouth rinse
Participants will perform a 20-second mouth rinse with 25 mL of water containing 3 mg/kg of caffeine from soluble coffee (Nescafé Classic) before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Caffeine Mouth Rinse Solution (Other)
Caffeine capsule
Participants will ingest 3 mg/kg of anhydrous caffeine powder in an opaque capsule 60 minutes before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Caffeine (Guinama Anhydrous Powder) (Drug)
Placebo mouth rinse
Participants will perform a 20-second mouth rinse with 25 mL of water containing decaffeinated soluble coffee (Nescafé descafeinado) before performing 60 minutes of cycling on a cycle ergometer at Fatmax intensity.
Intervention: Placebo Mouth Rinse Solution (Other)
Outcomes
Primary Outcomes
Rate of fat oxidation during submaximal cycling exercise at Fatmax intensity
Time Frame: 1 hour per experimental session
Continuous measurement of fat oxidation using indirect calorimetry during 1-hour cycling at Fatmax intensity. Calculated from respiratory gas exchange (VO₂ and VCO₂) using Frayn's equations. Unit of Measure: grams per minute (g/min).
Secondary Outcomes
- Rate of carbohydrate oxidation during submaximal cycling exercise at Fatmax intensity(1 hour per experimental session)
- Total energy expenditure during exercise(1 hour per experimental session)
- Mean Exercise Heart Rate(1 hour per experimental session)
- Oxygen consumption(1 hour per experimental session)
- Carbon Dioxide Production(1 hour per experimental session)
- Blood lactate concentration(Every 20 minutes during each 1-hour session)
- Rating of Perceived Exertion (RPE) during exercise(Every 10 minutes during each 1-hour session)
- Occurrence of caffeine-related side effects(Immediately after each session and 24 hours post-exercise)
Investigators
Daniel Trujillo-Colmena
Principal Investigator
Universidad Rey Juan Carlos