Hi Henry – a blood test for Chromium and Cobalt ions would be a good idea. In the UK there is a 3-yearly checkup on metal bearings due to the potential for wear and reactions to the debris, as per Karlos above (nice to see you here, Karlos!). My BHR is from Nov 2014, I run and bike and climb etc but I do not push as hard as you do (and I am much older!), my BHR is fine and I think it will last me out. I have a ceramic THR on the other side which in many ways feels better than the BHR but I am currently limping a bit with thigh pain which I hope is not related to the stem in my femur – this happens every 18 months after a period of overdoing things. Try backing off for a while if you get a good blood test, if you have to swap to a THR it is not the end of the road…
Good luck
Pete