Cardiio app review (iPhone)

In short what Cardiio does is measure your heart rate through two different methods of a similar basis. Cardiio uses light to measure your pulse through fancy MIT science stuff. The app as I see it is nothing short of magical.

Here is the alignment process that shows your face through an overlay

Here is the alignment process that shows your face through an overlay

The first method of measuring your pulse is through the front camera on your phone. All you need to do is center your face in this small circle and wait about 10-15 seconds while reading funny little phrases that scroll on the screen. One of the cool parts about this is that no one can tell you are doing it because it uses an overlay for your face on the screen. The accuracy for this method isn’t great, always within 10 bpm (beats per minute) compared to an actual chest HRM.

The second method is new and even more magical in a way. You place your finger tip over the rear facing camera and flash, in any light conditions, and the phone turns on the flash and then uses that light to measure your pulse. This is a very similar method to those new watches that measure your heart rate through a wrist watch only, no chest strap. They shine very intense little LEDs and measure with a super expensive little camera. Luckily the iPhone already has similar technology ready built in which saves you a few hundred dollars from buying a watch! The accuracy for this method is surprisingly good, it’s within 3 bpm compared to an actual chest HRM.



After you are finished measuring your heart rate you get more insight into what you bpm means compared to other.  Here are some of the screens that you can flip through to see the comparisons with your past heart rate and other peoples heart rate.  And then they for fun estimate your life span based on your HR.




There is also a new feature that was added in a recent update that helps you get in shape with a 7 minute workout. With Cardiio’s addition of the 7 minute workout they aim to improve your fitness which will also in turn lower your resting heart rate. The workout is a full body exercise that uses 12 techniques for 30 seconds each with 10 second rests in between.

I generally workout 1-2 hours a day so I decided to put this 7 minute workout through its paces by doing 3 sets in a row while tracking my heart rate . Here is a time lapse of me working through them in my hotel room:

Non-YouTube Source:


And here is a chart of my HR during the exercise with the lines showing the start and stop of each of the 3 sets:


A great simple workout for those wanting a quick workout session while traveling or with other limited means of exercise.  Would also be a good start for beginner athletes of all types, and of course to take it at their own level and do one session at a time.


For $1.99 at the app store I think it is a great deal.  The people behind the app are also very responsive if you have questions or feedback. I’ve emailed them twice about details in the app that I had questions on and heard back within 12 hours on both accounts.  I look forward to innovations and fine tuning by the Cardiio app people.  Head over to iTunes to pick it up:

Cardiio (iPhone) – Heart Rate Monitor, 7 Minute Workout, Calorie Burn Tracker

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Dario is an obstacle course racer and lover of great coffee. When he isn't writing on this blog he can be found working as a photographer for NYSE, AP, and occasionally Getty Images.
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    • says

      iPhone only at this time, send them a message to request android apps:

      Ming-Zher Poh, Ph.D.
      Co-founder and CEO
      mingzher [at] cardiio [dot] com

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