I was a regular brisk walker for 15 or so years, and in that time got colon cancer, PCa (Gleason 8) and also a BCR. I know it's all statistics, but I am on the wrong side of the ledger.
I don't doubt that regular exercise is good for general health, including PCa, but it's also possible to have too much of a good thing
No symptoms; PSA 5.7; Gleason 4+5=9; cancer in 4/12 cores
Non-nerve-sparing RRP 7 March 2008 age 63
Organ confined, neg margins. Gleason downgrade 4+4=8
Bimix worked well; now using just VED
PSA undetectable at first but then rose to 0.4, doubling time 7 months
Following diet change, PSA static at 0.4...