I drink a redbull
Sometimes btw I wake up in the morning and I can react to everything, while sometimes I can't play for shiz, wierd stuff.
As far as improving your reaction's go though, repetition helps so trainning mode surely helps. I just play the guys as many times as I can and I gradually get better at seeing things. As the article someone posted sais, the more used to situations you get, and the better you sort your thinking, the more room you will have for reacting around.