People are often surprised at how quickly the nurses get them out of bed after surgery. Sitting up in a chair makes it easier to take deep breaths and helps the lungs fully reexpand. It also helps prevent pneumonia. Moving your legs and walking aid blood movement though the veins in your legs, preventing blood clots.
Bedrest over just a few days results in deconditioning. All of our muscles will quickly lose strength if not used. Start with baby steps as soon as the nurses give you the green light. You may need a walker for stability at first. Your goal is to do a little more exercise each day.