"In my case, exercise makes me feel really good despite my medical conditions… "

That's exactly it. In the end, whether exercise actually delays cancer progression or not is irrelevant to the decision, since we *know* it mitigates side-effects and improves quality of life.

There's little downside, as long as you're safe to do it (e.g. under medical supervision if you have a heart condition) and don't OVERdo it (ADT is very unforgiving of overexertion, as we all discover sooner or later).