Moderate activity, running, body-weight exercises, etc. are ok. I once made the mistake of doing a heavy leg-weight workout (I was an internationally ranked al

Moderate activity, running, body-weight exercises, etc. are ok. I once made the mistake of doing a heavy leg-weight workout (I was an internationally ranked alpine ski racer at the time) on day-3 of a fast. It went great but the bonk afterwards was waayy more interesting than i bargained for - treading the line of unconsciousness and had to break it e12hrs early. Would definitely recommend zero instead of once, even if it seems to go well at the time.