There’s been a lot of hype over coconut water/juice as a sports drink. It is high in potassium 
and considered by some to be a more natural alternative to artificially flavored carbohydrate-electrolyte beverages.
I currently live in Southeast Asia and I love this drink. I’ve had it in bottled form and with the straw placed directly in the coconut (as pictured here).
But let’s not get too excited: according to research, this new alternative doesn’t rehydrate any better than other “artificial” sports drinks.
A recent study compared the responses of 12 exercise-trained men to bottled water, coconut water, coconut water from concentrate, and a typical carbohydrate-electrolyte sports drink. They trained for 60 minutes sessions of “dehydrating treadmill exercise” and were randomly given different drinks to recover. Subjects reported feeling more bloating and stomach upset with the coconut water drinks. Otherwise there were no differences in hydration, improvement in performance, etc. “Conclusion: All beverages are capable of promoting dehydration. Little difference is noted 3 between the four tested conditions with regard to markers of hydration or exercise performance in a sample of young, healthy men.”1
It seems this one comes down to personal preference. Coconut water seems just as effective as other sports recovery drinks, but not necessarily any superior in terms of hydration.
1. JISSN 2012, 9:1, (January 18) Comparison of coconut water and a carbohydrate-electrolyte sport drink on measures of hydration and physical performance in exercise-trained men
