Everybody who has had cancer should do some form of rehabilitation. It can be very comforting to meet other ex-cancer patients and talk about what all of you have been through. It is also very important to keep doing exercise during and after treatment, but what you do has to be adapted to the situation. For most people that means light sports which can prevent tiredness and help regain general health more quickly. It does not mean you should try to regain your former condition in the same way as in the past. Never overdo it, but consider light sports such as swimming, walking, cycling and rowing. Bit by bit you can do sport for longer periods, making the excercises heavier if you can.