A Study to See if an Energy Drink With Caffeine and Green Tea Increases Fat Burning When Exercising

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.

Inclusion Criteria: * Passing the Exercise and Sport Science Australia adult pre-exercise screening system (APSS) stage 1 \& 2 (see appendix 4). * Between the ages of 18 and 45, * Not sedentary, and not completing more than 150 minutes of low and/or moderate and/or or vigorous intensity endurance exercise a week, * Ability to commit to in principle fulfilment of all 3 trial visits, * No history of coagulopathy e.g., DVT, 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), * BMI of 22.0 to 34.9 kg/m2, * No known allergies to caffeine or green tea extract, * No known type I or II diabetes, * No uncontrolled concurrent illness, * No known current pregnancy or breastfeeding women * No current regular consumption of supplements (\>2 times a week) or foods and drinks containing caffeine and/or green tea extracts (\>2 times per day, weekly). * Agree not to consume caffeine for 12-hours prior to the clinic visit. Exclusion Criteria: * Triggering any of the exclusion screening criteria as outlined below, and in compliment with the Exercise and Sport Science Australia adult pre-exercise screening system (APSS). * Under the age of 18 or over the age of 45, * Sedentary, or completing over 150 minutes of low and/or moderate and/or or vigorous intensity endurance exercise a week, * Inability to commit to in principle fulfilment of all 3 trial visits, * History of coagulopathy e.g., DVT, stroke, * Known heart disease, * Known pancreatic insufficiency, * Known inflammatory bowel disease, or prior bowel resection or bypass surgery (excluding gastric banding and sleeve), * BMI \< 22.0 or \> 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 any other medication known to affect metabolism. * Known current pregnancy or breastfeeding women. * Currently regularly consuming supplements, foods or drinks containing a caffeine and green tea extract blend, or not willing to abstain for the study