Track your heart rate with your Fitbit device

Fitbit devices use optical heart rate sensors. These sensors use rapidly flashing green LEDs to detect blood volume changes in wrist capillaries. Light-sensitive photodiodes measure these changes.

Your Fitbit device calculates your heart rate in beats per minute (bpm). Infrared light detects when the device is worn to improve the accuracy of your heart rate readings.

Turn on heart rate tracking

Heart rate tracking is turned on by default. If you’ve turned it off:

1. On your device, open the Settings app .
2. Tap Heart Rate.

Device	Steps
Google Pixel Watch series	From the clock face, swipe left until you find the Heart rate tile. The tile shows your current heart rate and a graph of your recent heart rate. Tap the tile to get more details in the Google Health app . When you use the Fitbit Exercise app to track a workout, your heart rate appears on the screen. The Fitbit Exercise app tracks your current heart rate and heart rate zone. You can also use Gemini to get real-time data like your heart rate while you work out. For more information, refer to Gemini on Google Pixel Watch.
Versa 4 and Sense 2	From the clock face, swipe right or left until you find the Heart rate tile. The tile shows your current heart rate, a graph of your heart rate over the past 4 hours with your lowest and highest heart rate indicated, and your daily resting heart rate. When you use the Exercise app to track a workout, tap the screen to cycle through your real-time stats. The Exercise app tracks your current heart rate and heart rate zone.
Other Fitbit devices with screens*	From the clock face, swipe up to show your current heart rate and either your heart rate zone or resting heart rate if not in a zone. If your device has an Exercise app, you can check your real-time heart rate and heart rate zone during a workout.

*For the Fitbit Air, use the Google Health app to check your heart rate.

To check your heart rate in the Google Health app:​

1. Open the Google Health app  and tap the Health tab .
2. Under “Health areas,” tap Heart .
3. Under “Tracked metrics,” you’ll find your heart rate. Tap Heart rate to find a more detailed graph.
   • You can switch between a daily, weekly, monthly, quarterly, or yearly view of your data.
   • In the daily view, tap Learn more below the graph to learn how this metric is calculated.
4. Switch between days by tapping Left or Right beside the calendar icon.

Fitbit’s heart rate tracking accuracy is affected by your personal physiology, device placement on your arm, and the activity you're doing.

For a more accurate heart rate reading:

• Wear your Fitbit device on top of your wrist, and make sure the back of the device is in contact with your skin.
• Wear your device a finger’s width above your wrist bone when you’re not exercising.

• Wear your device a bit tighter and higher during exercise for an improved fit. The band should be snug but not constricting, as a tight band restricts blood flow and can potentially affect the heart rate signal.
  Many exercises, such as bike riding or weightlifting, cause you to bend your wrist frequently. This could interfere with the heart rate signal if the watch is positioned lower on your wrist.

To resolve common issues, go to What factors can affect my heart-rate reading on my Fitbit device?

My heart rate is visible on my device, but not in the Google Health app

If your heart rate is shown on your Fitbit device, but not in the Google Health app, your device could be disconnected from the app. For assistance with syncing issues, refer to Why won't my Fitbit device sync?

My heart rate readings are inconsistent between devices

Your Fitbit's heart rate readings might not always match those from other devices, like chest straps or other wrist trackers, due to differences in technologies.

Differences between heart rate readings on your device and on exercise equipment may also be due to wrist or hand position. Make sure the back of your device is in contact with your wrist and that your band is snug.

You might also notice variations between your heart rate reading on new Fitbit devices compared with your old ones. This is because of changes in the heart rate sensor or algorithm.

• Air temperature, stress level, alcohol or caffeine intake, immune response to illness, and medication use can affect heart rate (source).
• Cold weather can hinder your device's ability to accurately measure your heart rate during exercise because it affects blood flow to the skin.
• Sudden movements during sleep, like waking up and getting out of bed, or a poor wrist placement affecting the signal, can lead to increased heart rate readings.

Review our tips on How do I improve the accuracy of a heart rate reading?

For any concerns about your heart rate data, contact your physician.

Resting heart rate is the number of times your heart beats per minute when you’re still and well-rested. Typically, resting heart rate ranges from 60 to 100 bpm, but the rate can vary based on age and fitness level.

Why should I track resting heart rate in the Google Health app?

Resting heart rate can be an important indicator of your fitness level and overall cardiovascular health. Generally, active people often have a lower resting heart rate because their heart muscle is in better condition. Their heart muscle doesn’t need to work as hard to maintain a steady beat.

How is resting heart rate different from sleeping heart rate?

Your sleeping heart rate is detected continuously throughout the night, and is often lower than your resting heart rate, which is estimated each day. Learn more about your sleep data and sleeping heart rate.

In the Google Health app

1. On the Health tab, scroll down through your Key metrics until you see “Resting heart rate”.
2. Tap Resting heart rate.
3. You can view heart rate trends over time, including over the course of a week, month, 3 months, or year.
4. Scrolling down gives you your average resting heart rate over periods of time.

For more information about how this metric is calculated, scroll down to “About resting heart rate” and tap Learn more.

On the Google Pixel Watch series

1. Press the crown, then swipe up to the Google Health app.
2. Tap the app to open it.
3. Swipe to the Resting Heart Rate card, then tap the card to get more details.
   Tip: If you can’t find the Resting Heart Rate card, swipe left.
4. Swipe down to check your average resting heart rate for the past week.

Several factors can affect resting heart rate. Stress, alcohol or caffeine intake, or fever usually raise resting heart rate, while regular exercise or meditation can lower it. Air temperature and certain medications can also affect resting heart rate.

Heart rate zones, which are percentages of your maximum heart rate, can help you determine the intensity of your workout or activity.

Fitbit personalizes your heart rate zones using your heart rate reserve. This is the difference between your maximum heart rate* and your resting heart rate.

Heart rate reserve is an indication of your overall cardiovascular fitness. While your maximum heart rate is generally determined by age, your resting heart rate can be lowered when you increase your fitness level. When you lower your resting heart rate, you can increase your heart rate reserve.

For example, if you're 45 years old and your resting heart rate is 74 bpm:

1. Calculate your maximum heart rate and heart rate reserve.

   Metric	Calculation
   Maximum heart rate	175 bpm Common formula of 220 - age (45)
   Heart rate reserve	Maximum heart rate - resting heart rate
   Target heart rate per zone	(Percentage of maximum heart rate × heart rate reserve) + resting heart rate

2. Use your heart rate reserve to calculate your personalized heart rate zones.

   Heart rate zone	Calculation
   Moderate zone (Fat burn zone on some devices)	114 to 134 bpm Bottom of zone: (0.4 × 101) + 74 = 114 bpm Top of zone: (0.59 × 101 ) + 74 = 134 bpm
   Vigorous zone (Cardio zone on some devices)	135 to 159 bpm Bottom of zone: (0.6 × 101) + 74 = 135 bpm Top of zone: (0.84 × 101) + 74 = 159 bpm
   Peak zone	160+ bpm Bottom of zone: (.85 × 101) + 74 = 160 bpm Top of zone: Maximum heart rate

Check your personalized heart rate zones on the Active Zone Minutes screen

Important: Swim Active Zone minutes will no longer be available to certain FItbit devices.

1. Open the Google Health app  and tap the Health tab .
2. Under "Focus areas," tap Heart .
3. Under "Tracked metrics," tap Heart rate.

_{*Occasionally during intense exercise, you might notice your heart rate go above your Fitbit-calculated maximum heart rate.}

Google Fitbit Air, Google Pixel Watch series, Charge 6, Inspire 3, Sense series, Versa series, Charge 5, Inspire 2, and Charge 4

Personalized zones adjust as your fitness level or other factors change.

All other devices

Heart rate variability (HRV) is the variation in time between heartbeats. A heart rate of 60 beats per minute doesn't mean your heart beats exactly once every second. Your autonomic nervous system determines the timing of each heartbeat.

HRV varies from person to person. Studies show that people with a higher HRV have better cardiovascular fitness and might be more resilient to stress. Mindfulness, meditation, sleep, and physical activity can help improve your HRV. A significant drop in HRV may indicate that your body is experiencing illness, stress, or depression or anxiety.

Why should I track HRV?

Track your HRV in the Google Health app to help you gauge your overall well-being. Trends in HRV data can help you be more aware of how stress and lifestyle choices, such as nutrition and exercise, can affect your body

How does my Fitbit device track HRV?

Fitbit uses the common formula called Root mean square of successive differences (RMSSD) to determine HRV from your recent heart rate data. In the graph, your latest HRV measurement is from the longest sleep period over the past 24 hours. Only sleep periods greater than 3 hours are considered.

Wear your device for at least a full day, including to sleep at night. In the morning, check your stats:

1. Open the Google Health app  and tap the Health tab .
2. Under "Focus areas" tap Vitals.
3. Tap Heart rate variability (HRV) to check your data in detail. These details include graphs of your data over the course of a week, month, quarter, or year.
4. Switch between days by tapping Left or Right beside the calendar icon.
5. For details, tap Learn More next to "About heart rate variability."

Several factors can affect HRV, including age, sex, sleep quality, stress, and lifestyle choices, such as nutrition and exercise.

Google Fitbit Air, Google Pixel Watch series, Charge 6, Versa 4, Sense 2, Inspire 3, Charge 5, Versa 3, and Sense notify you when your device detects that your heart rate is outside of your high or low thresholds while you appear to be inactive for at least 10 minutes.

1. Open the Google Health app .
2. At the top left, tap Connections your device.
3. Tap Google Health reminders & alerts High & low heart rate.
4. Turn High or Low heart rate notification on or off.

When your Fitbit device detects your heart rate goes above or below your personal heart rate threshold while you’re inactive, your device notifies you.

To learn more about your data and complete a survey to log potential factors, medications, and symptoms, tap Open, and then the notification in the Google Health app. You can use the information you log in the survey to track your heart health trends and share it with your healthcare provider.

For heart rate alerts, both high and low heart rate alert thresholds can be customized (or turned off entirely). Thresholds are based on your age and typical resting heart rate.

To adjust your thresholds:

1. Open the Google Health app .
2. At the top left, tap Connections your device.
3. Tap Google Health reminders & alerts High & low heart rate.
4. Check the box next to Notification to turn notifications on or off.
5. Under either "High heart rate" or "Low heart rate," tap Threshold.
6. Turn off Use default.
7. Tap Set custom and choose a new threshold.
8. Tap Save.

To use your default thresholds, turn on Use default.