Maybe it would help if I wrote down what my objectives are. Obviously I do want to lose weight - fitting better into the Gi I bought yesterday would be a good start.
But let's just say that will be a very long term thing, to get down even to just an amount considered healthy. Patience is going to be a prerequisite.
I have no aspirations to be a "top athlete" of any sort...closer to the "walk up 80 steps" Dave suggested than running up any number of them. (even 30 would be an improvement). Or a two mile walk over flat terrain without much stress. More immediate goals would be "flexible enough to sit seiza properly", "able to do the forward rolls across the mat during warm-up" and to get through said warm-up without being breathless (noticing a change there already). Overall, I want to be a healthier and more disciplined person, not a gym jockey.
Michael H, the pool running sounds like a good place to start. Michael V, the foam rolling looks really interesting, I will look more into it. Janet, could you point at some reference for the sort of exercises you do? Alberto, the walking and the weights sound fine but I wouldn't last 5 minutes jogging yet, unless it was in the pool like Michael suggested.
Meanwhile, today's practice was much better. Still a little tight and sore going in, but I could do the rolls and the backfalls without aggravating anything, long as I did them more slowly. So feeling much more optimistic.