Actively Recruiting
Influence of Caffeine and Green Tea Extracts Consumption on Basal, Peri- and Post-exercise Fat Oxidation
Led by RDC Clinical Pty Ltd · Updated on 2026-04-16
40
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
Sponsors
R
RDC Clinical Pty Ltd
Lead Sponsor
A
Amway Corp
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are investigating whether drinking an energy drink containing caffeine and green tea extract before exercise can increase fat burning compared to a placebo drink. This study focuses on healthy, moderately active adults aged 18 to 45 and uses a double-blind, randomized, crossover design to compare effects during rest, exercise, and recovery periods. The study aims to understand how these ingredients influence fat oxidation during endurance cycling. Participants will attend three clinic visits over 3 to 5 weeks. The first visit determines their individual exercise intensity for maximizing fat use during cycling. In two later visits, participants will consume either two cans of the active energy drink or two cans of a placebo drink without caffeine and green tea extract before completing a 30-minute cycling session at their personalized exercise level. The study compares the effects of these drinks on fat and carbohydrate use and other physiological responses. During each visit, measurements will include fat oxidation, carbohydrate oxidation, respiratory exchange ratio, heart rate, blood pressure, and subjective responses, all assessed from baseline through 30 minutes after exercise using indirect calorimetry. Participants will be monitored closely, and the main outcome is fat oxidation from baseline to 30 minutes post-exercise. The total study participation spans three visits within a few weeks, providing detailed data on how caffeine and green tea extract affect metabolism during exercise.
CONDITIONS
Brief Title
A Study to See if an Energy Drink With Caffeine and Green Tea Increases Fat Burning When Exercising
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Passing the Exercise and Sport Science Australia adult pre-exercise screening system (APSS) stage 1 & 2
- Aged between 18 and 45 years
- Not sedentary and not completing more than 150 minutes of low, moderate, or vigorous endurance exercise per week
- Able to commit to attending all three trial visits
- No history of coagulopathy such as deep vein thrombosis or stroke
- No known heart disease
- No known pancreatic insufficiency
- No known inflammatory bowel disease or prior bowel resection or bypass surgery (excluding gastric banding and sleeve)
- Body mass index (BMI) between 22.0 and 34.9 kg/m2
- No known allergies to caffeine or green tea extract
- No known type I or II diabetes
- No uncontrolled concurrent illness
- Not currently pregnant or breastfeeding
- No regular consumption of supplements or foods and drinks containing caffeine and/or green tea extracts more than twice per week or day
- Agree to abstain from caffeine for 12 hours before clinic visits
You will not qualify if you...
- Failing any exclusion criteria from the Exercise and Sport Science Australia adult pre-exercise screening system (APSS)
- Under 18 or over 45 years of age
- Sedentary or completing more than 150 minutes of low, moderate, or vigorous endurance exercise per week
- Unable to commit to attending all three trial visits
- History of coagulopathy such as deep vein thrombosis or stroke
- Known heart disease
- Known pancreatic insufficiency
- Known inflammatory bowel disease or prior bowel resection or bypass surgery (excluding gastric banding and sleeve)
- BMI less than 22.0 or greater than 34.9 kg/m2
- Known allergies to caffeine or green tea extract
- Known type I or II diabetes
- Uncontrolled concurrent illness
- Taking GLP-1 agonists, caffeine, or other medications affecting metabolism
- Currently pregnant or breastfeeding
- Regularly consuming supplements, foods, or drinks containing caffeine and green tea extract blend or unwilling to abstain for the study
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 3 to 5 weeks
Participants consume either the energy drink with caffeine and green tea extract or a placebo before completing a 30-minute cycling session at their personalised exercise intensity. Measurements of fat and carbohydrate use, heart rate, blood pressure, and subjective responses are taken at rest, during, and after exercise.
3 visits (in-person)
Trial Site Locations
Total: 1 location
1
Griffith University, Gold Coast Campus
Southport, Queensland, Australia, 4222
Actively Recruiting
Research Team
L
Llion Roberts, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
TREATMENT
Number of Arms
2
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