Gentle stretches such as side bends, shoulder shrugs, arm circles, overhead stretches, and bending
to reach (but not touch) your toes are all good warm-up
exercises. Do three to five repetitions of each. If you are swimming or walking, you can also warm up with a slower swim or walk.
If you have OA in your knees or hips, you want to avoid any jolting exercise like jogging that causes your feet to pound the ground.