Hi Phil,
Welcome to the club! I’m a 71 y.o. male, and no where near the athlete you are. I have not yet returned to running, as I suffered several setbacks, and may be a bit gun shy to get back in the saddle. I am 12 and 14 months out from having both hips replaced. I still feel muscle imbalances, but they are gradually resolving. I recently tried a couple of physio sessions (not a sports specialist), but felt they were worthless. I may get a sports physio at a major medical center when I am a bit stronger. Currently, I am road bicycling 50-70km 3x a week, lap swim 1km 3x a week, and hit the gym for legs and upper body 2x a week for each.
Good luck with your jouney, and I look forward to following this thread regarding your progress and what others have to say.
Cheers,
Gary