Including Combat Sombo, which along with Judo, is basically where he got his start. Peep this video for something familiar, i.e. Fedor owning his competition in combat athletics:
This is the baddest man on the planet getting back to his roots. By the looks of it, the overlap between this and MMA is significant. No wonder he's so good.
More on Sombo here.
Decent biography of Fedor here.