Heart Rate Monitor ~ chest strap v.s. wrist sensor??

What heart rate monitor is good for hiking?

Chest-strap heart rate sensor

Embedded wrist heart rate sensor

There are a lot of devices which have heart rate sensors!!

Running devices, activity tracker, Apple watch and so on!

A several years ago, most of heart rate sensor for running was chest strap type.

Now, it is getting popular to use embedded heart rate sensor in a device.

I had a comparison about the accuracy!

Offset of measured heart rate between a chest-strap sensor and embedded wrist sensor

Offset of measured heart rate

I collected heart rate data based on my regular running exercise for a month.  I was wearing the both type of heart rate sensors, a chest-strap type and an embedded wrist sensor when I ran.

The chart above is the offset of the both measurements.  More than 90% of samples are within 4 (bpm).    This shows the embedded sensor is probably accurate enough for running and hiking.

Here is an example which has larger offset:

An example of larger offset 

The orange color is a data captured by a chest-strap sensor (with Garmin Forerunner 910XT).
In the middle of chart, there are some portion where the offset is bigger.  However the reading is more than 180 (bpm) which is probably way bigger for mild jog.  Therefore, I assume this data captured by a chest-strap sensor might be something wrong.

Another example is the the following:

Another bad example with larger offset

The blue color is captured by an embedded writ sensor (Garmin Vivosmart HR).  The early part, there are some spikes.  This data captured by an exercise using StarMaster in a gym.  It is hard to believe there is such spike during the exercise since the type of exercise won't introduce such narrow heart rate spikes.  Therefore, I assume this would be wrong reading by the embedded sensors.

Conclusion:The both sensors might have some wrong reading!

The both example shows there might be some wrong reading for the both sensors.  It is hard to identify the reason why the reading gets some offset.  Overall reading is matched well.   I think as long as contact between the sensor and body is good, the reading can be accurate.
My best guess is that if the contact is getting loose or dislocate a proper position to the body, the reading might be offsetting.

When people using a chest-strap sensor, it is probably easy to dislocate position due to a backpack.  I think that would be one of issue when I use the chest-strap type sensor during hiking.
Therefore, I would recommend embedded wrist sensor for hiking!

 

This device is with GPS function and it can track where you hike.

 

This device has pulse oximeter function, but no GPS.
It might be good to see your oxygen saturation which might be a good index for your body reaction of elevation!