Heart Rate Not Accurate During High Intensity Interval Exercise

[Bluekona]

After owning the Blaze for nearly 5 months and using it during many different activities I have noted that the Heart Rate monitor is not accurate.  The heart rate is typically off my at least 30bpm and I have seen it off my as much as 70bpm.  If you use a heart rate monitor as a tool for determing your rate of exertion relative to your the work your are doing, do not depend on your Fit Bit.  It simply is not accurate enough to keep up with the fluctuations that come with interval exercise. 

I have worn a Polar heart rate monitor along with my Fit Bit during High Intensity Weight Lifting, Plyometric work, Eliptical work and even running.  The Fit Bit is frustratingly inaccurate.  I would love for it to work, but it just doesn't.  I have called Fit Bit about the problem and they downloaded the latest update to my Fit Bit but nothing changed.  I have tried wearing the fit bit at different places on my arm and I get the same results.  Fit Bit is OK with steady exercise that does not cause sudden changes in heart rate.  But, if you do any kind of exercise that involves intervals the Fit Bit is not reliable.

Whe I contacted Fit Bit support on the issue I first believed that my Fit Bit was faulty.  But, after talking with their support people and being told that they would not send me a replacement I deduced that the Fit Bit was operating normally.  My concern is fof the novice that depends on the Fit Bit to help them monitor their level of exertion during intense interval training. The results could be catastrophic if they are using their heart rate as a guide to determine their percentage of VO2 max.  The Fit Bit is simply not reliable enough to use for this purpose.

[MikeS1971]

---

@Bluekona wrote:

The Fit Bit is simply not reliable enough to use for this purpose.

---

This has been a complaint about FitBits with heart rate monitors for quite a while. I'll track a six or seven mile run with my Blaze then when I check my stats when I get home, I usually find heart rate wasnt tracked at all for most of it. Same thing while I owned a Charge HR. The technology just isnt there for a wrist based heart monitor to be reliable.

[Croceau]

I have a slightly different problem, though I also find the heart rate (when it's given) wildly inaccurate. After instense exercise, like on the elliptical, I can't even get a heart rate.  I get dashes and a blicking heart icon.  Finally, at least a minute or two later, it registers but by then my heart rate has significantly decreased.

I have tried all of the suggestions in the FAQ.  I wear the Fitbit higher, wait 10 seconds (still doesn't register) and still it doesn't appear.  On the rare occasions that it does work, it is way under.  Like today, I was really pumping and there is a huge clock with a second hand right in front of me so I could do a manual heart check (fingers on pulse).  It was up to 170 bpm and the HR gave me 146.  Is there a maximum or something that it won't exceed?

I have given up on the stop counting thing (I hit 10,000 steps last week while stirring almond butter in the jar) but I really wanted a way to fairly accurately check my heart rate.