Five Apple Watch tips for a more accurate heart rate reading

By , Apr 22, 2015

Apple Watch heart rate sensor back 001

There’s no two ways about it: even under the most ideal of conditions, the Apple Watch may not be able to get a reliable heart rate reading every time for everybody. Now, our recent overview of the Apple Watch’s heart rate sensor provided a good starting point for enthusiasts wishing to learn more about the feature. It gives you a better idea of the intricacies and benefits of the custom-designed hardware feature marketed primarily to fitness aficionados.

But the truth is, it’s been designed for everyone, really. It’s something every Watch customer will be using without even being aware of it, simply by wearing the device (for those wondering, the average human heart rate is about seventy-two beats per minute).

On the back of the Watch is a specially designed sensor protected by a ceramic cover with sapphire lenses, with infrared and visible-light LEDs and photodiodes detecting the amount of blood flowing through your wrist at any given moment.

Knowing your heart rate helps the Watch determine your intensity level during workout while improving the accuracy of your active calorie burn measurements. Therefore, knowing the sensor’s limitations and pitfalls is important.

Luckily, there are some things you can do to help the Watch get the most consistent and best heart rate readings possible. Here are five sound tips regarding using this feature optimally and with minimal disruption.

A list of the five common factors that can influence the performance of the Watch’s heart rate sensor is as follows. The topics are covered in no particular order and accompanied by tips on getting a more accurate heart rate reading on the device.

1. Keep it close to your skin

It goes without saying that for the Watch’s heart rate sensor to work as advertised, the device needs skin contact. Apple itself explicitly states that the sensors will work “only if you wear Apple Watch on the top of your wrist”. A better fit means better readings. Therefore, if Watch is too loose and doesn’t stay in place, tighten its band. The band should be snug but comfortable, as shown below.

Apple Watch tighten band heart rate sensor

According to Apple, wearing your Apple Watch with the right fit — “not too tight, not too loose, and with room for your skin to breathe” — will keep you comfortable and let the sensors do their jobs.

2. Skin perfusion/environment affect performance

As the Watch’s heart rate sensor is basically a pulse oximeter which monitors the perfusion of blood to the dermis, it’s prone to inaccuracies. That’s because skin perfusion — a measure of how much blood flows through your skin — varies significantly from person to another.

Moreover, skin perfusion can also be impacted by the environment. There’s nothing you can do about making your skin more compatible with the Watch. Similar to the limitations of the Touch ID sensor, the quality of your skin’s blood flow will determine the accuracy of the Watch’s heart rate readouts.

3. Don’t exercise in the cold

Fitness nuts should avoid working out in the cold. As mentioned before, skin perfusion can be also impacted by the environment and exercising in the cold may bring down your skin perfusion levels, therefore reducing the accuracy of the heart rate monitor.

4. Avoid irregular movements

Rhythmic movements, such as running or cycling, give better results compared to irregular movements, like tennis or boxing. Apple advises tightening your Watch band for workouts to reduce any chance of false readings, then loosening it when you’re done.

5. Connect to external heart rate monitors

Not getting any heart rate reading at all? Tough luck. “For a small percentage of users, various factors may make it impossible to get any heart rate reading at all,” says Apple.

But worry not, friends, you can still connect your Watch wirelessly to external heart rate monitors such as Bluetooth chest straps and get a precise heart rate reading.

Wrapping up, there’ll always be naysayers and doomsayers coming out of the woodwork to chastise Apple because the Watch isn’t the most accurate heart rate monitor so let me put this bluntly — that’s life in the technology fast lane.

Apple Watch heart rate monitor teaser 001

As with any technology, there are limitations to what the Watch can do.

As a health-and-fitness tracker that’s attached to your body all day long, the Apple Watch is a pretty darn impressive piece of engineering, especially for a 1.0 product.

So, did you find these tips useful?

Sound off in the comments below.

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  • pnh

    Tip #6: Shave the fur off of your forearm.

    • Ryan Morano

      I’m actually curious about this. I’m sure not many people are Robin Williams knuckles hairy (RIP)…but most men don’t shave their arms. I wonder if this will cause any issues with the sensors.

  • M L

    Tip #7: Your watch needs to go from “Processing Items..” to “Preparing for Shipping”….

  • Freddy Born

    the last one is just genius

  • Snailpo

    Tip #8: You must have the device

    • Hi

      Awesome

  • Gregg

    Tip #9: You must be alive and have a heartbeat. If no heartbeat is detected, you may be a vampire. Please check your mouth for sharp, protruding, pointy teeth. Avoid direct sunlight.

    • Hi

      Hahahaha so funny. Erm what if they are a zombie?

      • Gregg

        Then that’s too bad – their arm falls off… 😉