My anecdotal experience with acute PMR onset at age 72 presented after overexertion biking and kayaking on vacation.
There is not much research found on exercise causing
polymyalgia.
Sometimes the diagnostic presentation can lead into
overlap with other rheumatic disorders that are aggravated by mechanical overuse. Don’t push yourself
to the max and follow up with your rheumatologist.
Your commitment to fitness will help forestall bone loss.
A very slow wean off steroids worked for me.