heart rates/cardio

[spacejamz]

how accurate are polar heart rate monitors? I have an S410...

I am 38 so if I do the 220 - age calculation, my max heart rate should be around 182.

I run 3 miles (in 30 minutes) on treadmill 3 times a week...I vary my speeds from 6.3 MPH to 8.0 MPH (the bulk of the running is down around 6.5 MPH and I kick it up to 8 MPH for 1 minute spurts) and take 2 or 3 one minute walk breaks (slow it down to 3.4 MPH) during each session. I have been doing this for about 5 months now (ran a distance of 2 miles when I first started - took around 23 minutes).

According to my polar, my max heart rate gets up to 192 BPM and my average during a workout is 174 BPM (this includes my post stretch routine which takes about 5 minutes.).

so are these polar heart rate monitors fairly accurate? I know the 220 - age is guesstimate, but it is pretty reliable, isn't it?

my upper target heart range should be around 140-160 BPM...do I need to maintain my current routine or should I change my workout to lower my BPM? what negatives, if any, occur if my workout exceeds my recommended upper target heart range?

 

[edcarman]

Polars are ECG accurate. They accurately measure every heart beat before applying whatever smoothing functions they use. The little blinking heart in the corner of the display blinks with every beat that the Polar picks up.

You can, however, get signal interference or strange readings if the chest strap isn't sitting properly. Fortunately, these values are usually obviously wrong (they show up as spikes of 232bpm on my S725). Apart from these spikes, my HR curves do not show any other anomalies when viewed on my PC and correlate well with effort. This gives me confidence in the accuracy of my Polar.

Here's some more data on abnormal readings:
Abnormal Heart Rate Readings During Exercise

I would trust the measured Polar values for your HRmax. '220 - age' is a general guideline for the population as a whole. It's individual accuracy can vary greatly.

I suggest changing your workout zones based on your actual maximum heart rate, as measured with the Polar. You can also use the RPE scale to check your zones.

 

[LongTimePCUser]

The accuracy of "220 - age calculation" is probably about +-20.
In other words, it is accurate enough to be of any use to you.

Remember too that your rest heart rate, just after waking up, is important. It is more meaningful to look at percent of (max heart rate - rest heart rate) when estimating exercise zones than it is to look at percent of max heart rate.

The best book analysis that I know of for using a heart monitor in your training programs is: Total Heart Rate Training: Customize and Maximize Your Workout Using a Heart Rate Monitor

This book actually tells you not to try to determine your actual maximum heart rate, which is hard to do and may be dangerous, but to use "lactate threshold" heart rates to estimate your target heart rate for exercise zones.