Originally Posted by puck1230
I want to just pitch in my 2c. I'm not going to get into the subject of amino acids or glycogen or whatever, because I have limited knowledge in that space. Just two quick things:
1. @Ramon @PowerPlayer, @CDestroyer on the subject of caffeine and b-vitamins: it may be semantics, but I don't believe they energy in the sense that the OP was looking for. They may keep you alert, but there's no useful cellular material to break down and convert into energy. It may change how your body is breaking down its various fuel sources, and it may change your state of mind, but isn't a meaningful fuel source in itself. All things equal, you can't replace food with vitamins/stimulants.
2. I try to follow the pros, even though I'm far from one. I would ask if all things being equal and no dietary restrictions, why would Nadal/Fed/Mahut/Isner and other endurance athletes, choose sports drinks (with sugar?) over drinks that have minimal to no sugar, like Xtend?
You are right about stimulants and vitamins not providing real energy. I don't particularly like to depend on stimulants, but I haven't noticed any negative effects when I tried taking pre-workout powders with stimulants before a match. They actually worked quite well, but if I took them in the evening, I couldn't get any sleep!
The way amino acids provide energy is a complex matter. Here are a few articles that might help:
You can see that there are several benefits of amino acids beyond being a source of energy. There are also health problems associated with being dependent on sugar, which is another topic altogether. I usually eat a high-carb meal before playing, and I find that enough to supply needed carbs.
Gatorade's marketing strategy includes sponsoring athletes and teams. That doesn't necessarily mean it's the best thing out there. I suppose if they gave me enough money to bring their drinks to the court, I would do it, but I would pick their lower sugared drinks and put my own mix into the bottles. I can't speak for the tennis pros and what they do. Beer worked well for Stolle and Newcombe!