I suspect a lot of us get momentary orthostatic (positional) hypotension (e.g. rise suddenly from a squat) resulting in lightheadedness. I know I do, particularly in a store when I've been in a squatting position for a minute of two looking at low items, then pop back to a standing position.

My doc says this is normal for athletic types, so, if this is you, too - no need to stress out, just put your hands on your knees, get your head lower for a moment until you feel normal. BUT, if this is you, and you're getting morning headaches, pay attention to how quickly you're jumping out of bed. Not an issue for me, but something that I've run across as a possible orthostatic symptom.

I've gotten curious as to what my overnight resting heart rate actually is (I see as low as 50 on an oximeter when I'm sitting still for a few minutes). I've looked at whoop and oura, but just can't get past how much I dislike wearing something on my wrist or finger. Both require subscriptions, but at the end of a year, the oura is a better deal. Both do HRV and track sleep. The whoop app looks to be a bit more 'naggy'. I haven't used either.

Maybe I'll just find an oximeter that doesn't beep so I can check when I wake and not wake my wife.