But to claim that it's 'dangerous' not to add salt to an energy drink is completely over-the-top. The above link posted by watchyourback is about the reydration needs of ultra-endurance athletes in hot conditions. We're talking here about a drink to give you a boost at the end of a long ride under British conditions.

The end of the article below distinguishes nicely between isotonic drinks, energy drinks, and recovery drinks ('sports drinks jargon buster') -

http://www.pponline.co.uk/encyc/sports-drinks.htm