Track your health metrics in the Fitbit app

Breathing Rate (BR)

This metric is the number of breaths you take per minute. Your body usually adjusts your breathing rate to help you get enough oxygen. Typically, breathing rate is 12-20 breaths per minute.

Track your average breathing rate during sleep to help you assess your overall well-being. Typically, your average breathing rate during sleep won’t vary significantly from night to night.

Factors that can affect breathing rate include sleep, altitude, some medical conditions, medications, or drug use (including alcohol).

For more information, refer to How do I track breathing rate in the Fitbit app?

Heart Rate Variability (HRV)

Heart rate variability (HRV) is the variation in time between heartbeats, determined by the autonomic nervous system (ANS). We use the RMSSD formula to determine heart rate variability from heart rate data.

HRV varies from person to person. Age, sex, sleep, hormones, circadian rhythm, and other factors (for example, caffeine or alcohol intake, exercise, and stress) can affect HRV.

Studies show that a higher HRV is linked with better health. A significant drop in HRV suggests that your body may be experiencing stress, strain, or showing potential signs of illness.

For more information, refer to How do I track heart rate with my Fitbit device?

Skin temperature

This metric is the variation in your skin temperature taken from your wrist while you sleep.

Core temperature is the temperature inside your body usually taken with a thermometer. Skin temperature is the temperature on the skin's surface which varies throughout sleep and from night to night.

Factors that may cause skin temperature to vary nightly include changes in room temperature, bedding, circadian rhythm, menstrual cycle, or the potential onset of fever.

Note: Significant changes in ambient temperature may negatively impact skin temperature tracking.

For more information, refer to How can Fitbit help me track my temperature?

Oxygen saturation (SpO2)

This metric estimates the amount of oxygen in your blood. Nighttime SpO2 is usually lower than daytime SpO2 because your breathing rate is usually slower during sleep (typically above 90%).

Tracking SpO2 can help you be more aware of your oxygen saturation trends during sleep. Your blood oxygen levels tend to remain relatively constant, even during exercise and sleep.

Note: To collect SpO2 data, install an SpO2 clock face (available on Sense, Versa, Versa Lite Edition, Versa 2, and 3), or the SpO2 app (available on Charge 4, 5, and 6, Luxe, Sense, Sense 2, Versa 3 and 4).

For more information, refer to How do I track blood oxygen saturation (SpO2) with my Fitbit device?

Resting heart rate (RHR)

This metric is the number of times your heart beats per minute when you're still and well-rested.

Resting heart rate varies (60-100 bpm) depending on age and fitness level. This can also indicate your fitness and cardiovascular health. Active individuals tend to have lower resting heart rates.

Several factors can affect resting heart rate: stress, alcohol or caffeine intake, or fever usually raises your resting heart rate, while exercise or meditation can lower it. 

Note: Air temperature and certain medications can also affect your heart rate.

For more information, refer to How do I track heart rate with my Fitbit device?