Welcome @puppytlc, I'm not sure there is a definitive answer to your question. Everyone is different. For me, my first time with PMR took 3 and half years to play out then returned 6 years later and lasted for 1 and half years. I do think moderate exercise and diet play a part in helping those of us with PMR. My second time around was much easier mostly I think due to lifestyle changes I made after learning more about my condition.

Here is some information that might be helpful if you haven't seen it already.
-- Can Diet Affect Symptoms of Polymyalgia Rheumatica?:
https://www.healthline.com/health/polymyalgia-rheumatica-diet
@dadcue and others may also have some thoughts and experience to share with you. Have you done any research on the condition?