Quite a few people who are dabbling in yoga are doing so from the purely physical perspective.
And I'm definitely not judging you for that!!
However, even if it just a toned bum you're after, not enlightenment. Or just injury recovery rather than spiritual healing... it would be worth checking into some of these programs as a 'nod' to the vast and rich background of India where yoga was developed.
I aim to listen to most of them... hopefully they'll release a CD or something but tuning in through BBC iplayer usually. Buddha was the first episode and I think you can still get it on iplayer (hurry!)
But for yogis interested in learning more about the context from which all your asana and your suranamaskars come from... it is well worth a listen!