When I don't do jiujitsu, I have started running again.
Running and I have a love/hate relationship and I have tried almost every approach unsuccessfully that you can possibly imagine. And it wasn't until I read this book that I started having some successful performance, and funny thing is, this isn't a Running Training book per se, but so much of it has absolutely changed the way I run.
I am definitely a member of the run gentle, run slow, run long camp. And while this may put me at odds with the "Running has no point for BJJ, but if you do it run sprints" camp, it has helped no only to help me sleep better, manage my stress and weight and so much more. Definitely check this book out if you can. Who knows, maybe someday, I might run a marathon or even an ultra.