Your Apple Watch can tune in to your heart and send notifications when something out of the ordinary occurs. For example, your Apple Watch can notify you if your heart rate remains above a chosen threshold or below a chosen threshold after you’ve been inactive for at least 10 minutes.
You can turn on heart rate notifications when you first open the Heart Rate app, or at any time later.
You can also receive a notification if your Apple Watch has identified an irregular heart rhythm that appears to be atrial fibrillation (AFib). If you have already been diagnosed with AFib, your Apple Watch can help you understand how frequently your heart is in this arrhythmia. You can also track lifestyle factors that may influence your condition.
Apple Watch can provide you with cardio fitness estimates by measuring how hard your heart is working during an outdoor walk, run, or hike, and sending you a notification when it’s low. Depending on your age and sex, your cardio fitness will fall into one of four ranges: Low, Below Average, Above Average, or High. If your cardio fitness level falls in the Low range, you’ll receive a notification on your Apple Watch. If it stays low, you’ll receive a notification every 4 months.
Go to the Apple Watch app on your iPhone.
Tap My Watch, tap Heart, then tap Set Up Cardio Fitness Notifications in Health.
You can also open the Apple Watch app on your iPhone, tap My Watch, tap Heart, then turn on Cardio Fitness Notifications.
Look in the Cardio Fitness section of the Health app to see your cardio fitness measurements and the range they fall into. Tap Show All Cardio Fitness Levels for more information.