[Aromasin]

Same here. I knew my workouts were harder if I had a couple of beers the previous evening, or a big session a couple days prior, but having the data to say "your heart rate is bouncing around like a moth near a lightbulb" makes ignoring it much harder. My midweek drinking has diminished to nothing now, because I like feeling well rested all day more than I appreciate a glass of wine after work.

[etrautmann]

Isn’t heart rate variability a good thing?

[8bp]

Mostly, yes. Heart rate variability ties into the sympathetic and parasympathetic nervous systems. When both are in balance, heart rate will fluctuate with the alternating activation of those nervous systems.

Although I'm sure there's variations in heart rate that aren't healthy.