Originally Posted by
PatW
Even with exact measurement of the heart beat, heart rate is an interpretation of the data. I do not know what algorithm Polar uses. There are all sorts of ways to come up with a heart rate. The easiest would be to take the last 2 beats, measure the interval between and lift the rate from that. I don't think that kind of method would be the most accurate. It might be best to do a moving average of the last 5 heart beats intervals or better yet a weighted average with more weight with the more recent heart rate.
But what the cyclist REALLY wants to know is their heart rate at this instant in time. If your heart rate is speeding up or slowing down, the monitor will be a bit inaccurate because it has to use the past data for its estimation. One could come up with a method of estimating the instantaneous heart rate by the rate of change in the recent intervals but that seems like a bit too much.
This is my problem - the sampling rate and the period over which it is taken... the device must be accurate to track this over a wide range. There is data to be gained by tracking these changes in athletes and those with cardiac problems. The standard HRM will average out any small perturbations to be safe. That is why i don't think they're accurate in the medical sense.