How do i get faster?

I've been around mid gc1-gc2 for about a year now. Recently i managed to almost get gc3, but being this high obviously means faster gameplay and more consistency. I'm low c3 in 1s now, going against peope, that are gc3s in 2s and i get absolutely outpaced by them. Also a thing is that when they go in the air i either give them a lot of time to setup the shot, or i just don't go up.

My questions are: How do i get faster, do i just have to play the game more or is there a way you can train this? And how can i get better knowing when and how to challenge in the air?