Resting heart rate

[mtl543]

From the help article about heart rate measurements:

"Resting heart rate refers to the heart rate measured when you’re awake, calm, comfortable, and have not recently exerted yourself."

"We use your heart rate data from when you’re awake and asleep to estimate your resting heart rate"

First question: is resting heart rate measured when I'm awake or awake and asleep?

Second question: does skin hair - I've a lot of skin hair on my arms - according to studies affect heart rate measurement  during an exercise?

[RicardoFitbit]

Hi @mtl543 thanks for your inquiries, I'm here to answer them for you. Also, it's nice to see you again participating in our forums, welcome back! 

Thanks for taking the time to review our help article: How do I track my heart rate with my Fitbit device?, this information is always helpful for a better understanding of how heart rate data is measured with your Charge 2. The answers for both of your questions are below:

First question: Resting heart rate is measured when you're awake and during your sleep time as well.

Second question: Heart rate may be affected by any number of factors at a given moment. Movement, temperature, humidity, stress level, physical body position, caffeine intake, and medication use are just a few things that can affect your heart rate readings. As with all heart-rate tracking technology, accuracy is affected by personal physiology and location of wear too, that said, I recommend you to check our help article: How do I improve the accuracy of my heart-rate reading? for tips while you're exercising. 

I'll be here if you have any additional questions.