This is good news in a lot of ways. Most of us like chocolate milk more than sugary fruit tasting water. Based on this study at least it gives us chocolate lovers a legitimate argument for downing some after exercise. It's also less costly by a wide margin since it's considered a legacy treat rather than some fancy sport drink.
During matches I'd be more thoughtful of taking in electrolytes myself.
Chocolate Milk - the next sports drink? - August 17, 2015
Chocolate Milk or Energy Drinks? - October 13, 2010
As you can see this story is old news being made new again.
This brings us back to basics. If you want carbs it comes down to versions of sugar and in the case of milk it's lactose. With chocolate milk you get the caffeine that comes with it in addition to the good taste. If you want a pure caffeine boost then there is always coffee but without protein and carbs you have only added a stimulant. It seems that chocolate milk covers all of the bases in a moderate amount with good taste as a bonus. I wouldn't overdo it but rather than spending so much on expensive health and sport drinks consider chocolate milk as another option.
Tennis Players: I'd probably not drink chocolate during the match but rather consider it a recovery option. During a match remember liquids, electrolytes, and even simple treats like bananas.
