Heart rate while exercising

[acepirtle]

I jog the same route every day -- the last 2 days -- even while increasing my speed -- the heart beats are about 20 beats lower than normal.  Also on Friday -- I had a stress test on treadmill -- while on treadmill -- my HR was 30-40 points lower than what was showing at same time on stress test.  Is something wrong with algorithm?

[Lexamundo]

I did a Google search yesterday and found an interview with the female scientist? engineer? who created the optical heart rate sensor technology.  Today it still isn't great during the highest intensity exercise but it's better than it was when she created it.  Yea.   When I lift weights my actual heart rate is 20-30 beats higher during the 'work phase' of an exercise than the Blaze indicates.  So Blaze won't give me credit for a butt-kicking workout.  Having had a Garmin I think it's the fault of the technology more than the manufacturer.  IMHO

[SunsetRunner]

Unlike a chest strap optical sensors do not measure the electrical impulses to the heart that show actual heart beats taking place, as such devices using optical will never be as accurate as the devices used in stress tests or even chest straps but they still give a very good reflection of heart rate, not enough to diagnose murmurs or other heart problems, but quite suitable for determining fitness levels and fitness improvements.

[schmict]

This optical technology is OK for averages over time,  not so much for working out accuracy.  That is too bad because that's why many people buy fitbit, to gauge when they get into certain zones real time, especially if you are doing intervals it is not suitable...you will never know where you are really at.