Thanks Joel, that's what I was thinking. The downside to bjj is that after years of training your actual skill level and understanding of the positions/submissions improves and you become much more efficient. Kind of a double edged sword because the technique allows you to be lazy (or more than at the beginner stage). I just finished about 10 weeks of starting strength so I decided to alternate between general endurance and general strength for a while, starting with the endurance block. Thanks to everone for the replies and I'll keep you posted on my results.
As a side note- When I was training MT a lot, my usual fitness level plummeted when I trained and sparred with non aggressive guys (ie not the 'take the fight to them' ones).
There was too much of a chess game going on with these and the energy expenditure was minimal. It got to the point where I didn't train fitness specifically, as I didn't see what the point was. So I know where you are coming from.
Good luck and keep us updated.
Regards
Ian