Sports drink are designed to replenish fluids lost during activity. They typically contain water, electrolytes and sugar. Energy drinks have added caffeine and other ingredients that their manufacturers say increase stamina and "boost"performance.
Energy drinks can deliver on some of their promised benefits by increasing brain function and helping you function when you're tired or sleep-deprived. However, there are a number of health concerns with energy drinks, particularly related to excessive caffeine intake, sugar content and mixing them with alcohol.