Keith Thomas keeps a great site at EvFit.com looking at a whole range of issues in the evolutionary fitness field - the sort of terrain occupied by Art Devany, Loren Cordain and the paleo diet.
I read through the whole site a few years back and really got a lot from it. While I did not agree with everything, he certainly got me thinking. He hadn't updated the site for a couple of years - he blames problems with his internet host - but I just noticed that he has added to the site.
Have a look at Physical activity basics - May 2008 where Keith talks about his current exercise programme.
Good thought-provoking stuff.