If you have had a knee replacement, it's likely that you are an older adult with arthritis or at least some type of joint degeneration. An exercise program to maintain motion, strength, and balance is still very important for you.
You may be able to drop back from a daily program of specific exercises for your knee and leg to one that's done three or four times each week. But you should keep up with other activities such as walking, biking, golfing, tennis, or other recreational sports that you enjoy.
If you are having any trouble with walking, stair climbing, or other daily functional activities, then it may be time to have your exercise program re-evaluated. Your physical therapist can do this quickly and easily and help you get on a better track for what you need and/or want to do.