I found a great website that shows how to make your own sports drinks from fruit juices. It seems much cheaper and healthier than just buying Gatorade or Powerade.
Recipe from BRT Insights : http://brt-insights.blogspot.com/
Hydration Fruit-Ade recipes for 2 quarts (64 oz).
Fruit juices vary widely in the amounts of sugar that they contain. Read the Nutrition Facts on the label of your juice to learn how much sugar it contains per 8 oz serving. Then use the table below to dilute your choice of fruit juice to the exact sugar level that is needed in a sports drink. Add stevia or other sugar-free sweeteners or flavor enhancers if needed.
|sugar per 8 oz serving||amount juice||amount water||amount salt|
|8g||64 oz||0 oz||1/4 tsp|
|12g||43 oz||21 oz||1/4 tsp|
|16g||32 oz||32 oz||1/4 tsp|
|24g||21 oz||43 oz||1/4 tsp|
|32g||16 oz||48 oz||1/4 tsp|
|40g||13 oz||51 oz||1/4 tsp|
|48g||11 oz||53 oz||1/4 tsp|