I have just followed an American link on Facebook and as I haven't the skill to copy to you I will have to tell you what was written.
To prevent dehydration you need to work out your optimum fluid intake per day.
Take your weight in lbs. Divide by 2. Drink that number of ozs in fluid per day. There are 20fl ozs of water per pint. That's an awful lot of liquid for me!!
There is also emphasis about how energy drinks are likely to trigger arrhythmia due to the caffeine content.