Why Did Apple Change How Resting Heartrate is Calculated on Apple Watch

Back in October of last year I was sick. I caught a bug that lasted for almost two months, even going to the doctor and getting a short-term prescription for steroids. I’ve been tracking my Apple Watch data for several years and I then noticed my resting heartrate jumped from the low to mid 50s to the high 60s and even 70s seemingly overnight. 

I thought it was an adverse reaction to the steroids or something to do with the bug I had. My doctor said to give it some time and it would come down, but after several months it was still high. I made another doctor appointment and he said it was likely because I’d put on a few pounds (less than 10 over about six months), so I went on a rigorous diet and started exercising like crazy, only my resting heartrate didn’t change. 

Cut to today when I happened across an article that said the way the resting heartrate is calculated changed with WatchOS update 11.2 (which came out in late 2024, around the time I saw the jump on my resting heartrate) to average throughout the day, where in 11.1 is was just while sleeping! Thanks so much for making this clear, Apple, and having me almost have a meltdown that something was significantly wrong with my heart! I really appreciate that.

Has anyone else had a similar experience to this? Why did they change how they calculate your resting heartrate?