[C19is20]

I can recommend apps like kubios (my fav), hrv4 and elite hr (I use all three daily). Coupled with even a cheap heart rate monitor, you can see the effects of 'everything' on your body/ soul as well as track sleep etc. Oura rings do similar, but they're subscription based.

[netizen-936824]

I second this. These monitors are invaluable for gaining insight into how we're doing health and stress-wise

[_gshc]

Any recommendation for a decent but cheap tracker?

[TheAdamAndChe]

I've got the Garmin Forerunner 45s, I like it a lot. It's got a built in GPS, so you can track your runs without bringing a phone.