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Saturday, October 17, 2020

Heart rate monitors (HRMs)

 "Freedom is secured not by the fulfilling of men's desires, but by the removal of desire" -Epictetus
I've become a believer in heart rate monitors only very recently - just about two years ago.  
 
I used the single-purpose Polar F1 for the past couple of years, and it was awesome!  One button starts the timer and begins displaying your pulse.  Your pulse is displayed continuously while you exercise, and when you push the button again, it briefly displays your average heart rate, followed by the elapsed time between when you first and last pushed the button.  Pretty simple.

I recently tried out a Polar A3 wristband.  They both use the same chest transmitter, so there wasn't much expense involved in trying out the new rig. 


 The A3 is a dual-purpose wrist band.  It's a watch that displays the day and date, and also begins functioning as a heart monitor when you push the big button on the front.  There are a couple of things to like about this new wristband and a couple of things to dislike.

One of the things that I like is that you activate the heart rate monitor with the first press of the large button, but that first press doesn't start the timer.  The first press allows you to verify that it's receiving the signal, and to get your heart rate in the target zone before starting the timer.

Both wristbands while not monitoring.  Left: F1 heart monitor.  Right: A3 watch/heart monitor. I like the large display on the F1.

Below:  I have pressed the big front button on both monitors.  The F1 on the left is now counting this as exercise time.  The A3 is displaying heart rate, but the timer is not yet running in the background.

Below:  The button on the right watch has been pressed a second time, and the timer is now counting this as exercise time.  The top digits indicate the target heart rate.

So far, so good.  I like the delay feature to get set up for exercise and check your heart rate before beginning.  Lack of signal was an issue a couple of times on the F1, and with the F1 you never know if you have a signal until you start monitoring and timing your workout.

Another thing the A3 does that is nice is if you bring it close to the transmitter on your chest, it will briefly display time - Not the elapsed time, but time of day.  You must remember to note whenyou started exercising, and subtract in your head to figure out the elapsed time during the workout.  The A3 will display elapsed time at the end when you push the big button, but not during your workout.

The A3 doesn't have a light, making it useless as a watch during the winter months and at work on night shift in areas where there is poor lighting.  One thing I like about both wrist bands is that they are powered by CR 2032 lithium batteries, and I don't have to worry about recharging them every few days, like modern sport watches.  Also they are not smart watches, so they are not reporting my physical conditioning level to every snooping company on the internet.  I also like that they use a chest strap to get a strong signal directly over the heart muscle.  My experience with the heart rate monitor on the elliptical grips is that it's incredibly erratic and inaccurate compared to the Polar heart monitors.

I did a bit of research on the inaccuracy of monitors that do not use a chest strap:  They are not too accurate at higher exertion levels - which is the point of exercising.  Link to the study is here.

Below is a graph of an Electrocardiogram vs several newer heart monitors at various heart rates.  Quite a bit of data scatter when you use the wrist as a monitoring point for heart rate.  Fitbit (Graph C) seems to be the worst, and Polar with the chest strap (Graph A) correlates the best.


 

I have a wish list for a heart rate monitor/watch, and here it is:

  • Uses a chest strap to get a signal from the source. 
  • Displays Time and Date.
  • Has a button to illuminate the display, as needed
  • When monitoring heart rate, shows only the heart rate and elapsed time
  • No bells and whistles beyond that.  Don't need a "target zone", 50 lap split memory, or any of that other stuff.  Complexity for its own sake sucks.  It makes life more difficult than it already is.
  • Absolutely no "Smart watch" you must be internet-connected or it won't function shit.
  • Self-powered.  I don't want to plug it in all the time.  More complexity and daily chores.

If any sporty-type people happen across this post and know a monitor that mostly meets these specs, I'd love to learn more!  Thanks in advance!

Edit: I'm done with the A3.  When I work out, I'll use the F1, until I find a great dual-purpose HRM.  Unless I'm exercising, I'll be wearing my trusty old Timex Ironman with Indiglo.




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