Caffeine is a commonly used ergogenic aid among endurance athletes due to its stimulative effect. It works by dilating blood vessels, increasing blood flow and blood pressure, which in turn increases cardiac output and muscular endurance. Not only can caffeine improve physical performance but also mental performance such as memory, learning, reaction times and delay perception of fatigue. For an ergogenic effect, 3 mg/kg body weight (BW) provides the most significant effect with 9 mg/kg BW causing overdose symptoms (e.g. severe gut issues). Caffeine dosage from coffee is dependent on the type of coffee bean. The main effect of caffeine is noticed ~30 minutes after consumption.