Not everyone responds well to caffeine but if you do then it is a great asset to have in your running tool box when used correctly. Caffeine before or during a long run can help boost your energy levels by dilating the blood vessels which allows energy to travel to the muscles and through the body more quickly.
Caffeine is a known stimulant, increasing nerve signals to the brain which produces adrenaline and can make you feel pumped. With controlled intake of caffeine runners can feel more powerful and run faster. It can also reduce fatigue by improving cognitive levels such as mental alertness and clarity.