Use whatever you can get a good shot with. Typically, if I am shooting something like a race/some freestyle events, so a relatively constant exposure, I use manual. Take a few tests during warm up, and I'm good to go.
On the other hand, my mother uses a 6D with a 70-200 f2.8L to shoot picks of my little bro playing hockey. For being indoors, there is a surprising variability in the exposure. I usually do something like set the aperture wide open or at f4 (depending on rink), and then ISO somewhere around 2500 (6D is great at high ISO), which forces it to use a fast enough shutter. Alternative is to lock the shutter at 1000+. Both ways work pretty well, and in this situation it is "better" than manual, because it is also ready and gives her a high keeper rate.