[qtrim]

Can the heart rate monitor be turned off to save battery life?

[miketko]

Good question. Wonder how much battery life we would save.

[warcraftWidow]

I don't think it's on continuously unless the watch is in the Workout app.

[anon(5787457)]

Haven't found an option to turn the sensor completely off....

[JakePleasants]

I don't think it's on continuously unless the watch is in the Workout app.

I think it is, because when you check your pulse, it always says xxBPM 5 minutes (or so) ago. So it seems to check it in the background and store it for you, and I haven't setup the workout/activity app.

[kch50428]

https://support.apple.com/en-us/HT204666

How Apple Watch measures your heart rate.
The heart rate sensor in Apple Watch uses what is known as photoplethysmography. This technology, while difficult to pronounce, is based on a very simple fact: Blood is red because it reflects red light and absorbs green light. Apple Watch uses green LED lights paired with light‑sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. When your heart beats, the blood flow in your wrist — and the green light absorption — is greater. Between beats, it’s less. By flashing its LED lights hundreds of times per second, Apple Watch can calculate the number of times the heart beats each minute — your heart rate.

The heart rate sensor can also use infrared light. This mode is what Apple Watch uses when it measures your heart rate every 10 minutes. However, if the infrared system isn’t providing an adequate reading, Apple Watch switches to the green LEDs. In addition, the heart rate sensor is designed to compensate for low signal levels by increasing both LED brightness and sampling rate.

[kd7irm]

It can be turned off I believe, open the Apple watch app, then privacy, motion, then toggle off heart rate..

[Quackinup]

Don't believe you can turn it off completely, but it can be disabled while using the Workout app.

[John Yester]

HR Monitor won't use that much. I have a Fit Bit charge and it lasts 4 days. Everything else app wise and screen will effect battery on Apple Watch.

I know when it's not on your wrist the HR will turn off, then turn back on once it makes contact with skin.