On the days when I’m the busiest, I sit a lot. As a freelancer, it’s way more than I’d be in my seat if I worked in an office.

I don’t have to get up to walk to meetings. I don’t have anyone to wander over and talk to when I need a break. I sit to work, to talk, to eat my lunch. There are days when my FitBit barely squeaks over 5,000 steps because all the walking I’ve done is during my 30 minutes on the treadmill.

It’s not good to sit this much, but as a freelancer, it’s up to you to...