watchos
Set low and high heart rates on your Apple Watch to ensure your alerts become more relevant
•Manage your heart rate alerts •Train for a 10K run
Although you’ve long been able to get alerts when your heart rate rises above a set level for a period of ten minutes of inactivity, only with watchos 5 can you be notified when your ticker’s beats-per-minute (bpm) drops below a certain level. It’s an important addition, because a low heart rate can indicate a serious condition such as an electrolyte imbalance or coronary artery disease. Being alerted to such a drop means you can hot foot it to the doctors to get treatment.
In order to make best use of the feature, you may want to better tailor it to suit your body. As it stands, Apple Watch will alert you if your bpm falls below 40 at rest, but you can alter that to 45 or 50. Similarly, you’ll be alerted by default if your bpm rises above 120 at rest, and again this can be changed. For most people, a rate of 60 to 100 bpm is considered normal, and anything lower than 60 is slow, so that’s worth bearing in mind.