A Phase 4 interventional study of Active (Green tea and caffeine) and Placebo in Exercise, sponsored by RDC Clinical Pty Ltd. Active, not recruiting at 1 site in Australia. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by RDC Clinical Pty Ltd · Phase 4, Interventional, and Treatment
The goal of this study is to evaluate the influence of consuming a drink containing a combination of caffeine and green tea extracts on fat oxidation responses at rest, during and after a period of endurance type exercise.
This study investigates whether consuming an energy drink containing caffeine and green tea extract before exercise increases fat burning (oxidation) compared with a placebo drink. Healthy, moderately active adults will attend three visits at clinic over 3-5 weeks. The first visit determines each participant's individual exercise intensity that maximises fat use during cycling. At two subsequent visits, participants will consume either the active drink or a placebo before completing a 30-minute cycling session at their personalised intensity. Fat and carbohydrate use, heart rate, blood pressure, and subjective responses will be measured at rest, during exercise, and after exercise using a double-blind, crossover design.
2,426 studies on the registry are indexed under Motor Activity; 1,161 are open to participants now.
This study's enrollment of 36 is below the median of 60 across 2,118 interventional studies indexed under Motor Activity.
Browse Motor Activity studies →RDC Clinical Pty Ltd is the lead sponsor of 34 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Two 355 mL cans of "XS Energy + BURN" drink containing caffeine and green tea extract.
Dietary Supplement: Active (Green tea and caffeine)
Two 355 mL cans of placebo drink but without the active ingredients (caffeine and green tea extract).
Other: Placebo
Two 355 mL cans of "XS Energy + BURN" drink containing caffeine and green tea extract.
Also known as: XS Energy + BURN
Two 355 mL cans of placebo drink but without the active ingredients (caffeine and green tea extract).
Fat oxidation as measured by indirect calorimetry
Change from baseline to the end of the study period in Fat oxidation as measured by indirect calorimetry (metabolic cart); baseline (pre-drink), post-drink (pre-exercise), time sequence e.g., every 5-min during exercise, 10, 20 and 30-min post-exercise. Change from baseline \& total. Fat oxidation will be measured continuously throughout the exercise and the 30-min post-exercise window, to facilitate total, and any other temporal fat oxidation timepoints.
Time frame: Baseline to 30 mins post exercise
Carbohydrate oxidation; indirect calorimetry
Change from baseline to the end of the study period in Carbohydrate oxidation; indirect calorimetry; same timing as fat oxidation (baseline (pre-drink), post-drink (pre-exercise), time sequence e.g., every 5-min during exercise, 10, 20 and 30-min post-exercise.). Change from baseline \& total.
Time frame: Baseline to 30 mins post exercise
Respiratory exchange ratio; indirect calorimetry
Change from baseline to the end of the study period in Respiratory exchange ratio; indirect calorimetry; same timing as fat oxidation (baseline (pre-drink), post-drink (pre-exercise), time sequence e.g., every 5-min during exercise, 10, 20 and 30-min post-exercise). Change from baseline \& total
Time frame: Baseline to 30 mins post exercise
Exercise efficiency; indirect calorimetry
Change from baseline to the end of the study period in Exercise efficiency; indirect calorimetry; time sequence during exercise e.g., every 5-min. Change from the beginning of exercise \& average
Time frame: Baseline to 30 mins post exercise
Tertiary: Compliance monitoring
Compliance monitoring for adherence to clinical trial components e.g. consumed volume of investigational product; ability to complete the necessary duration (30 mins) and intensity (at fat max) of exercise; adherence to immediate pre-trial control procedures of no caffeine or green tea extract in the 12 hours leading up to the experimental, arrival at the laboratory after an overnight fast
Time frame: Baseline to end of study period (week 5)
Tertiary: Adverse Event monitoring
Adverse events will be monitored throughout the study across the study periods.
Time frame: Baseline to end of study period (week 5)
Tertiary: Perceived gastrointestinal (dis)comfort questionnaire
Change from baseline to the end of the study period in Perceived gastrointestinal (dis)comfort; measured via a questionnaire.
Time frame: Baseline to end of study (week 5)
Tertiary: Perceived satiety / hunger
Change from baseline to the end of the study period in Perceived satiety / hunger; measured via questionnaire.
Time frame: Baseline to end of study period (week 5)
Tertiary: Perceived exercising exertion
Change from baseline to the end of the study period in Perceived exercising exertion; measured via questionnaire.
Time frame: Baseline to end of study period (week 5)
Tertiary: heart rate
Change from baseline to the end of the study period in heart rate. Pre, during and post exercise heart rate.
Time frame: Baseline to end of study period (week 5)
Tertiary: blood pressure
Change from baseline to the end of the study period in blood pressure. Pre, during and post exercise blood pressure.
Time frame: Baseline to end of study period (week 5)
Tertiary: Safety via AE monitoring
Change from baseline to the end of the study period in safety via AE monitoring.
Time frame: Baseline to end of study period (week 5)
Tertiary: Anthropometry - BMI
Change from baseline to the end of the study period in BMI.
Time frame: Baseline to end of study period (week 5)
Tertiary: Anthropometry - weight
Change from baseline to the end of the study period in weight.
Time frame: Baseline to end of study period (week 5)
Tertiary: Anthropometry - waist circumference
Change from baseline to the end of the study period in waist circumference.
Time frame: Baseline to end of study period (week 5)
Plan to share: Undecided
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This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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RDC Clinical Pty Ltd