Meanwhile, on the other side of the jiu-jitsu spectrum, there's this
Marcelo's 100% Training Philosophy
The caption for this video, while worth reading, is a little misleading. The point isn't just that Marcelo devotes 100% of his training to jiu-jitsu rather than dividing his time with specific strength and conditioning workouts. More importantly, Marcelo is showing those who choose this path just how intensely they need to train - regardless of the skill level of their training partner - in order to make the "jiu-jitsu, si / conditioning, no" approach work in the real world.
I think this is especially relevant for those who want to be active in competition jiu-jitsu ("sport" jiu-jitsu is starting to become an epithet), but don't - or can't - devote time to separate strength and conditioning sessions. There has to be a place for competition-style intensity if you aren't going to be doing off-mat conditioning and Marcelo's short video shows how it's done.