During chemo, I usually was in very bad shape and not very inclined to do any training.
In the few days when I was feeling OK (usually just before the next cycle of chemo was about to start) I used every opportunity to restore my shape. My aerobic capacity was decreasing very fast, but my muscles still were more or less OK.

I guess that after 2 cycles of chemo, aerobic performance was down to 30% of my top shape, and muscle performance down to 65% of my top shape.

Actually, I do not know if it's possible to avoid this.
Chemo-time is not training-time.
And it would be plain stupid to try to *increase* your shape during chemo - your body is at its limits anyway, even without training.

Well yes, there possibly is one way: take an anabolic steroid instead of cortisone. But that's not possible during BEACOPP (because cortisone is part of the protocol).

Anyway.

We took a stroll on Marswiese when I shot this photo of my Lady.