I had to have time off all my activities when I had my breast cancer treatment. No cycling, no kayaking, no swimming etc. from having surgery until I recovered from my radiotherapy. It was about 4 months in total. When I asked what I was allowed to do, it was suggested I could do a brisk walk up to 5km per day, so that's what I did. It was something of a struggle to get back to normal after that, but it comes back eventually. It would have been much worse if I hadn't kept moving!