It’s natural to want to get back to the exercises you were doing before your surgery.
How soon you start, what type and how much physical activity you do after surgery will depend on the type of surgery you’ve had, your recovery and your fitness level before your surgery. Although you mention you have had a mastectomy you don’t say if you have had any surgery to your lymph nodes in your armpit. If you have had some or all of your lymph nodes removed its important for you to do regular arm and shoulder exercises to regain your range of movement that you had prior to your surgery.
Most people will usually be advised not to lift or carry anything heavy until their wounds have fully healed. If you take things gently at first, you should be able to return to most of your normal activities within a few weeks of your operation, but this will vary from person to person. Although you should be able to return to any sporting activities, including body workouts, weights and yoga that you did before your surgery, if you haven’t been doing these activities regularly, you’ll need to start slowly and gradually build up.
It may be helpful to contact your breast care nurse or treatment team, as they will be able to provide advice on practical issues such as when you can introduce exercise.