3 ms·

So I ride bikes and always monitor my heart rate while working out. I've always used a chest-based heart rate sensor until I started trying wrist-based about 4

by deaps 8y ago

So I ride bikes and always monitor my heart rate while working out. I've always used a chest-based heart rate sensor until I started trying wrist-based about 4-5 years ago. I've used countless brands and models (ranging in price from about $49.99 up to about $399) on my wrist - and literally none are as accurate as the chest-based strap. The chest strap responds immediately to increases and decreases in heart rate. Whereas the wrist sensors always seem to lag, sometimes by up to a minute or so. The wrist-based sensors always seem to differ depending on where on the wrist they are worn - high, low, inside of the wrist, outside of the wrist, etc - by maybe 5 bpm or so. In either event, if you really want to test the accuracy of the wrist-based sensor, you should really compare it to the output of a chest-based strap. In fact, the results will largely be personal - because the electric signals may differ per person greatly in different areas of the arm. Needless to say, my apple watch is worn daily, but when riding, I have gone back to a chest-based strap. That all being said, there is a guy that reviews these gadgets and will often wear 2-4 sensors while working out, and post an overlay of the results from his workouts. The baseline should generally always assume that the chest-based straps are accurate. His site is called DCRainmaker, if anyone wanted to look up his comparisons/reviews.

jnwatson 8y ago
The wrist lag is the biggest problem I have with my Fitbit wrist band. It is OK for looking backwards of how my overall work out went, but it is useless for trying to hit a target heart rate.
DoctorOetker 8y ago
I wonder if the difference in results is partially due to a difference in measurement strategy: a naive way is to wait one minute while counting the pulses which will necessarily be slower in response (it could still update the screen at a faster rate of once per second by having 60 different integers but each integer gives the count displayed on the screen when it's last second has passed, but that would still have a slow response in the sense that given a hypothetical heart rate change from a fixed constant initial rate to a new fixed higher rate, like when you got scared by say unexpected fireworks, it would still take a minute for the final rate to show up). A faster response could be got by measuring the time between heartbeats (probably a low but even number of beats).

by deaps 8y ago

jnwatson 8y ago

The wrist lag is the biggest problem I have with my Fitbit wrist band. It is OK for looking backwards of how my overall work out went, but it is useless for trying to hit a target heart rate.

DoctorOetker 8y ago

I wonder if the difference in results is partially due to a difference in measurement strategy: a naive way is to wait one minute while counting the pulses which will necessarily be slower in response (it could still update the screen at a faster rate of once per second by having 60 different integers but each integer gives the count displayed on the screen when it's last second has passed, but that would still have a slow response in the sense that given a hypothetical heart rate change from a fixed constant initial rate to a new fixed higher rate, like when you got scared by say unexpected fireworks, it would still take a minute for the final rate to show up). A faster response could be got by measuring the time between heartbeats (probably a low but even number of beats).