Good observation! I actually wore my watch everyday -- that extended period of 0 minutes of exercise corresponds to January 2021 (ish), which is when I started a full-time work-from-home job. Prior to that I was working part time in a lab, which required leaving my apartment (and I often walked to or from work). I also had a bit more free time/flexibility to work out prior to starting the new position. I found a better balance starting in the summer of 2021 and then left my job in the summer of 2022, hence the major increase in activity over the last few months.