Caffeine is a stimulant most commonly found in tea, coffee and other beverages. It is used both recreationally and medically to restore alertness when a person feels sleepy. It’s also quite addictive. In sports drinks, caffeine is found in extremely high quantities whose efficacy has been questioned in recent times. It is widely used in supplements also and helps improve endurance in athletes. It also decreases perceived exertion during the performance and may also increase people’s ability to fun fat while exercising. Dieticians and nutritionists don’t recommend taking more than 400 mg/day which would roughly equate to 3 cups a day. Another issue that comes with extreme caffeine consumption, especially in energy drinks, is a phenomenon called caffeine crash which leaves the consumers highly tired after a period of elevated energy.