Resting Heart Rate (RHR) is the number of times your heart beats per minute when you're at rest. It's a good measurement of your sleep quality, recovery and overall health. Normal RHR for adults can range anywhere from 40-100 BPM. The best way to determine your normal level is by looking at your own data history.

Oura measures your heart rate throughout the night and displays the lowest 10-minute average it has detected. It evaluates the optimal level for your RHR by studying your data after active days and recovery days for a couple of weeks. Once it knows your normal range, your Readiness Score will start to become more accurate. 

Oura interprets a RHR slightly below your average as a sign of good readiness, whereas an exceptionally high or low RHR is a sign of increased need for recovery. A sign of good recovery is that your RHR reaches its lowest point during the first half of the night. 

What affects your resting heart rate?

Your RHR is affected by various factors, such as physical activity, nutrition, body position, and environment. A low RHR is often associated with good fitness and overall health. Your RHR can be elevated after a late night workout or when your body temperature is higher than your average. Alcohol, a heavy meal before bed or late exercise speed up your metabolism and keep your RHR elevated, delaying your recovery and increasing your sleep needs. 

For women, the menstrual cycle can cause a small increase in RHR during the second half of the cycle (ovulatory and luteal phases). It’s also normal for your RHR to be higher than usual when recovering from an intense training day. As you increase your training volumes and your fitness improves, your RHR should start to decline over time.

Learn more: American Heart Association