At our office, we started doing "stair climbs" mid morning and mid afternoon. We got a small bell and whoever got to the bell first would ring the bell and then head to the front door. Anyone who was free and wanted to join would join at the sound of the bell. It was simple, no pressure to join, most people can't join everytime anyway so that was totally acceptable. Some days it wouldn't happen at all, but it was always good to try to break free and make it happen.

Most of the time it was a group of 2-5 people. When the group was only 2 or 3 people it often became similar to a smoke break where you could have a good discussion as you climbed up/down the full set of stairs.

The beauty of it was that almost everybody felt comfortable participating in it. If you have non-ambulatory coworkers who want to participate, perhaps a walk would be better. Management also liked it better than smoke breaks because they were always trying to lower health insurance costs so it was beneficial to encourage people to be more healthy.

Our building is 12 stories, so 1 complete up/down was pretty good and even the less healthy people could do it well after a few tries. If you're on a middle floor, go up/down/up (or the reverse) until you get back to your floor. If your building is taller/shorter then you may want to adjust the number of cycles. People who get tired can always exit at any floor and take the elevator back, but peer pressure usually pushes most people to exceed their comfort limit a little bit.

It was also a great team bonding experience because everyone wanted the whole team to make it and it was exciting when someone new joined or when you saw someone's physical ability improve. It's still not a smoke break, but it's the next best thing I've found... other than maybe grabbing a coffee/tea with someone.

it's also a (decreasingly) culturally normalized break. it can feel strange to stand still or wander about aimlessly otherwise.