This thread starts with: I am 75 and am very tired every afternoon. I need a two hour nap. My blood work is good. Any comments that can help me get more energy?

Since turning 80 I feel a 30 min nap most days (on top of a sound 8 hr sleep) does make my waking hours fully energized.

Haven't seen my provider for over eight years. But I do what is basic for fit and healthy life: Mostly plant based food (see Harvard Health, e.g.) daily physical exertion engaging all parts of body and Using brain/intellectual work. There's a reason Brain uses 20X calories than muscle. (The first time I found, I had to look it up!).

Except for checking my pulse rate as I walk up stairs in my building often returning with 20 lbs of grocery and seeing if I can walk up beyond the 2nd floor my apt. is, I get to more than twice my normal rate after three more floors and continue with another 3 to 5 to feel the top huffnpuff level.
I rarely done any tests, take no meds, supplmts. But I am sure, like most of us , we were much stronger as young adults. No point Comparing our older selves with the younger us, only we can try what OUR near-best is