The website BJJ Hacks specializes in making awesome documentary style videos on Brazilian Jiu Jitsu, both the art and its practitioners. Their YouTube channel is full of grappling goodness and is well worth your time and subscription.
In this mini series BJJ Hacks works with BJJ and Judo black belt Claudio Calasans. Reguarded as one of the best Middleweight grapplers in the world, Calasans has won him multiple Pan Am Championships, European Opens, and is a four time World Pro Cup Champion.
Calasans trains out of Atos Jiu Jitsu, and actually started out as a competitive Judoka who trained BJJ as a supplement skill set, but slowly closed firmly over into practicing jiu jitsu.
The full three episode mini-series featuring Calasans covers his thoughts on conditioning for BJJ athletes and how he merges Judo and Jiu Jitsu to great success.
A Workout for Jiu-Jitsu Athletes & Calasans's Top Techniques || BJJ Hacks TV Episode 5.2 (via BJJ Hacks TV)
How to Adapt Judo for Jiu-Jitsu with Claudio Calasans || BJJ Hacks TV Episode 5.3 (via BJJ Hacks TV)