the truth is that they don't work for the average person but will for the top athlete they are more of a money making way rather than a genuine drink that boosts your performance they are very deceiving aswell you would think they were very healthy but in fact they are very fattening and high in sugar the best way for you to keep energy when exercising is to keep hydrated by drinking water also eat a banana.the way i like using is having a jam sandwich and water before i exercise and keeping hydrated while you exercise and don't drink to much water as it can kill you so only drink when your body tells you to. know one has ever died by not drinking enough water in exercise it just leaves you feeling ill but people have died from over consuming water during exercise. by using the method i use will save you alot of money aswell if you would like to find out more about energy drinks and why they don't work watch this panorama episode here. [ Register or Signin to view external links. ]