The purpose of this project is to investigate the effects of caffeine chewing gum on the cognitive functions and special operations capabilities of special forces.

Using a randomisation crossover design, 20-40 active-duty special forces members who had undergone leave and special forces reserve training were divided into a caffeine trial (CAF) and a placebo trail (PL). After chewing caffeine-containing gum containing 5 mg/kg (CAF group) or caffeine-free gum (PL group) for 15 minutes, then performed a simple reaction test, a stroop test, a visual search test, a grip strength test, a vertical jump test, a 20-metre sprint test, and a counter-terrorism simulation test. A heart rate monitor was used to measure the heart rate and heart rate variability of the participants. Saliva samples were collected and analysed for α-Amylase, cortisol and caffeine concentrations before the test, after a 15-minute break from chewing gum and at the end of the test. Completion time of cognitive functions, grip strength, vertical jump height, 20 m sprint time, time to completion of the counterterrorism simulation test, and target score will be analysed using paired-sample t-tests.

Inclusion Criteria:

• Active Special Warfare Unit members who have passed the Grade A Special Forces Reserve Training
• No cardiovascular and joint diseases
• Adult male over 20 years old

Exclusion Criteria:

• Non-active Special Warfare Unit members
• Have cardiovascular and joint diseases
• Under age

Only male subjects