I have to agree with Upyu regarding Rickson, in 'Choke', he's clearly doing some solo stuff on the beach that's similar to yoga (not to mention something like a nice Capoeira ginga). Given how many of the Gracies have admitted to training in different things and then later sometimes go on to say, "100% Brazilian Zhoo Zhitsu!" . . . (then we hear wrestling tournaments and sambo matches . . .)
Not that any of it is unrelated . . . I'd argue it's all related . . . but it ain't all just BJJ