Resting heart rate on my fit bit varies between 57 and 73. It alters after the weekend,when I have had my weekend G&Ts and red wine. During the week if I stay on track with my sugar levels it also drops. If I’m going through a raised period, (I know I know, not good, but tends to happen every couple of weeks even when I’m not eating or doing anything differently) the resting heart rate rockets, it is very interesting.