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