At age 50 I had gall bladder surgery the old fashioned way...with an 8 inch incision. I think they gave me too much anesthesia or something because my heart beats became irregular. That continued until I retired at 57 and took up playing golf 4 to 5 times a week and walk 18 holes. My heart beats became regular, like you my hearing improved, my energy levels improved, sex improved, weight dropped! Now in my 70’s, I am still going strong...I chalk it off to daily walking on golf course or the treadmill at home. I rarely take any supplements, eat whatever is handy, and do not need regular doctor visits.
It’s amazing isn’t it. The difference is tremendous. People wonder why when they were kids they had so much energy. It’s not just because kids are younger, it’s because kids are always running around. What was weird was when I started exercising again all those feelings I had when i was a kid returned, smells, hearing, that high from energy. People do get damaged by age but not much. Jack LaLanne for example when he was 70 towed 70 rowboats filled with 70 people while he was handcuffed and shackled across San Francisco bay. How many 20 year olds can do that? As long as people excercize not much changes.
Walking is VERY good for you.
Carry on.