Thanks for the helpful responses.

Nitro: I'm currently on a short-term disability absence from work.

Nitro and SEM: thanks for sharing your experiences with me.

Mark: I think paying attention to the subtle cues indicating a risk of overdoing it is good advice. I have become better at doing this, but on Wednesday I mistakenly assumed I could add some more activity into the mix. Now I know I need to take things more slowly as I recover.