Using the Sharath CD, I'm noticing that the holds on some poses are much, much longer. For example, in Utthita Hasta Padangusthasana, I've already noticed that I have more stability in the pose from just a few days practice of holding it longer. The same with headstand - I'm sweating by the time I've held it for 15 counts, plus 10 in half-bend.
Navasana is repeated five times and this is just too many times for me at the moment. So I'm taking it with baby-steps. First Navasana: my knees are bent, calves parallel to the floor. Second Navasana: raise the legs just a bit higher...and so on. Fifth Navasna: completely straight legs. I find that in Ashtanga, taking things in increments really works.
I was reading back in my archives from last year and noticed that when the Chaturangas were too much for me, I started doing them with my knees on the floor. When I could do all of them in this modified fashion, I upped the ante and did every other one with straight legs. Now, Chaturanga is easy for me because I've built the strength.
I believe this principle also applies to life: sometimes baby-steps are the best steps to take.
I had a good practice today. I was cold when I started and sun salutations didn't seem to do a lot to warm me up. But once I moved into the seated poses, I broke into a sweat. I'm finding a better breath-focus this week. Although it's hard to get on my mat - it takes some self-will, I'm finding practice very soothing once I get going.