I bought my kayak a couple of years before my diagnosis. It's a sit-in kayak, not a sit on. I haven't paddled since diagnosis. The first summer I was going through radiotherapy. By the next summer I had developed tenosynovitis in my wrists and was advised against it. Shortly before this summer, I started having problems with my shoulder. I also struggled to get out of the bath, so figured that getting out of my kayak would be even harder. I am thinking about an inexpensive sit-on, as i really miss paddling, not so much from an exercise perspective as from a mental health perspective.
Take it slowly, to start with @Brenda5, it's well worth it in the end.
As a casual paddler, I don't paddle in winter - Canberra gets a bit chilly. If any of you are interested, check out the Kayakcameraman on facebook. He started paddling after treatment for testicular cancer, and takes the most amazing photos from his kayak.
Lyn