I know this is not a strength training post, but I am guessing that you can still help with with the basics since you are doctors who have learned much about sports science.
I used to be an avid runner who ran everyday. However, after I broke my foot and was diagnosed with a disease, I stopped due to pain. It has been 3+ years since I have run more than a couple of strides at a time, and I deal with fear about the health of my feet due to prolonged foot pain issues (such as it taking 8+ months for a lightly broken toe to feel normal again). I want to run so as to build resilience in my feet and overcome my fear. Do you have any good insight or resources on how I can conservatively begin to be aerobically active again? Thanks.
I would start running 1x/wk at ~20-25 min @ RPE 6 (e.g. <130 bpm HR, can speak in long sentences comfortably). This may be more or a run/walk. I would stay there until you can run the whole time while keeping your HR under that mark, then increase the duration. 2 other days per week I would plan on going for a brisk walk for 30-40 minutes.
Later, I would increase the frequency and replace the walking 1 session at a time (every ~3 weeks) if you’re trying to prioritize running.