I'll be 52 next month but it was my mid 40's when I started to really feel it. Slowly started to wean myself off risky outdoor activities that just flat out kicked my ass and could leave me crippled if I screwed up. Have been borderline pre-diabetic for a long time, all diet related, and it was causing most of my issues with general pain, inflammation, and slower recovery from anything basically. My diet is better, but still not great and got on the old man meds when I turned 50 (low dosage lisinopril, pravastatin, allopurinol, and metformin) and feel like my early 30's again. LOL