Heart rate variability - what is is, why is it important, how to improve, what to track
This question may have been answered already! Apologies if so. I recently started tracking heart rate variability with my fitbit watch (can't afford an Oura ring yet ;)). I was surprised to see that for the last three nights, the measurement has been quite low. I'm a 47 year old woman, with (according to charts I've consulted), a pretty good resting heart rate for my age and sex (although it could be better and has gone up during COVID), but my HRV was 25-26! I thought it was supposed to be double that for someone my age ... not sure what this means. Also, 3 data points does not a trend make so will wait until I have a month's worth of data. Are all devices the same in reliability and method to measure HRV? How is it measured via a device like a ring or watch? Why is it measured during sleep? Are other times of the day better to measure? In the meantime, upping my zone 2 exercise, and especially deep breathing, yoga, and meditation to calm a nervous system that might be in overdrive despite my best efforts. Thanks for wonderful work you do! Podcast and this opportunity to connect via membership has legitimately changed my life for the better.
Torn between adding muscle and calorie restriction for longevity
I consistently conflicted about how to approach the second half of my life. On one hand I hear a lot about caloric restriction being a key driver of longevity. On the other hand I hear about maintaining muscle mass as a key driver of longevity. For me it seems to be one or the other. I'm naturally lanky and caloric restriction seems to prevent me from gaining much strength/muscle. When I ramp up my calories I can put on some muscle but then I'm not getting the benefits of caloric restriction. How should I think about this from a longevity perspective?