Step outside the house every now and then when working remotely

To promote your health, it's best to get out of the house and stay active. Your body needs blood circulation. Plus, the fresh air and natural light will do you good. Ideally, step outside for at least a short while before, during, and after your working hours. This advice equally applies to people who do in-person work. Leave the building at least once a day during working hours. 
If you have the time or you live close by, consider visiting cafes, libraries, and co-working spaces to break up the redundancy of being at home. That's great, but the crucial part is to leave your home, get some air and sunshine, and move. You don't have to go to crowded public spaces to get away from your solo workspace. Take a walk. Weed the garden. Sit on the stoop. You get the picture.