Another "should have been obvious" thing, but it isn't:
Pediatricians Group Raps Energy Drinks and Sports Drinks for Kids
Most of the kids I see exercising at games, swim class, kid's baseketball, even t-ball, end up with a sports drink or energy drink in their hands afterward. The article goes into the why nots in more detail, but here are the main reasons I have to avoid these for kids:
1) Extra calories they probably don't need.
2) Excessive caffeine - energy drinks especially have high levels of caffeine for an adult, never mind a child.
3) They didn't work that hard. No, seriously. Sports drinks are great if you did a truly exhausting workout and need to recover quickly in order to continue exertion. Soccer practice, pee wee football games, that karate promotion, or running around in the park aren't sufficiently "hard" for these to help. If they must drink something other than water, milk or chocolate milk is fine - get them something with fat, carbs, and protein with minimal additives, coloring, and caffeine.
My advice - keep you kids active and stick to water post-"workout"!