Low heart rate = No Active Zonr mins

[dave_in_ni]

I am someone who is fairly fit, ive a resting heart rate in my high 40's, the problem I have is because my heart rate is low and never gets overly high I don't get any active zone mins,  I went for a run this morning, 4k took 25 mins, No Zone mins. I tried playing around with custom zone but that didn't do anything.  Any ideas? Its a bit disheartening tbh.  My heart for example doesn't go above 140-150bpm

[shipo]

Hmmm, I have a resting heart rate in the high 30s and have never had a problem getting "active minutes" recorded.  I just looked at a recent 16km run, it took me 104 minutes, I had an average BPM of 128 and a peak BPM of 143; this run showed me with exactly 104 "active minutes".

Long story short, I don't think your low(ish) heart rate has anything to do with your tracker logging active minutes.

[dave_in_ni]

Yeah perhaps its dodgy, looking at my heart rate it should have registered cardio at least but 0, same thing happened today and I lowered everything right down in settings

[NellyG]

Hi @dave_in_ni  I'm with @shipo on this. My HR is usually in the higher 40's or low 50's and I have NO problem getting zone minutes. My HR doesn't go up dramatically when I exercise -  I have to work pretty hard to get it over 100 and I get awarded a lot of zone minutes. I generally reach my weekly goal on day one or two. I think it awards them to me too readily. So something doesn't seem right with yours....

[LZeeW]

@dave_in_ni   Something is definitely amiss, because you wrote that your recorded heart rate should be in the cardio zone.  Seriously, if you could keep up that pace (6' 15"), it is near elite marathon pace.  Can you post a screenshot or two that shows this error?  Also, you can see your zones when you tap on you zone minute tile.  What are your zones?  What did your exercise details list for your average and peak heart rate?

Custom heart rate zones are designed for training purposes.  Those zones don't change fat burn/cardio/peak thresholds.  Changing your maximum heart rate will change your zones.  But I don't think this is your problem at all.  I really don't.

@shipo   I calculated your pace as 6' 30".  I'm confident you would have earned over 200 zone minutes for your run. 

[shipo]

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@LZeeW wrote:

@shipo   I calculated your pace as 6' 30".  I'm confident you would have earned over 200 zone minutes for your run. 

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I'm not sure I understand, I ran 10-miles/16-kilometers in 104 minutes; why do you think I should have earned over "200 zone minutes"?

[LZeeW]

@shipo   Zone minutes award you 1:1 for each minute in the fat burn zone, and 2:1 for each minute in the cardio and peak zones.  Given the average heart rate you listed, then I suspect you would have spent much of the time in your cardio zone.  Given your stated pace, I suspect you spent much of your run in the cardio zone where each minute awards you two zone minutes.

[shipo]

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@LZeeW wrote:

@shipo   Zone minutes award you 1:1 for each minute in the fat burn zone, and 2:1 for each minute in the cardio and peak zones.  Given the average heart rate you listed, then I suspect you would have spent much of the time in your cardio zone.  Given your stated pace, I suspect you spent much of your run in the cardio zone where each minute awards you two zone minutes.

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What you are reporting is something I've never once seen in the 5+ years I've been wearing a Fitbit tracker; here is the "Zone" graph from the run I reported on earlier:

Two comments on the above graph:

1. My Ionic was on it's last legs when I recorded this run and for the last six or so months has reported a crazy spike in my heart rate at the beginning of most (roughly 90%) of my runs; my new tracker does not have the same issue.
2. In addition to comment #1, the GPS functionality was failing; the course I ran on that day is virtually always 10.2 miles (plus or minus .05 miles).

As for the so-called "Zones", I view them as more "urban legend" than anything else, and as such, I completely ignore them as they are utterly meaningless.

[Baltoscott]

@shipo - "Active Zone Minutes" are are the new(ish) way that Fitbit calculates activity and the calculation is a bit different than the old "Active Minutes." Your Ionic is on the list of devices that have AZM, which, for the the run you posted would be 2x ( 5 min peak + 55 min cardio) = 120 min + 43 min Fat Burn = 163 minutes. But when the Ionic came out I think it used active minutes, so if you haven't updated it may be calculating your activity using that metric.

[shipo]

My Ionic had the latest and greatest firmware version when it finally died; I've always kept my Fitbit trackers up to date with the latest release.  Like I wrote before, never have I seen any 2x calculations in any of the so-called zones.

[t.parker]

@dave_in_ni a few things to check:

- what your zones are? (Fitbit uses heart rate reserve to determine your zones)

- is captured HR is correct (if you running with GPS you can export TCX file to see)

- knowing your zones, you can try to use the exported data and compute your AZM manually to see what it should be

- do you know your max HR? (and I'm not talking about 220-age, that's BS).

The resting HR affects your heart rate reserve. HRR isn't a perfect method to estimate zones. For me, it assumes the wrong max HR (180bpm, while in reality it's 188bpm). My RHR is 42 but for a sake of computation, I will assume it in the high 40s and set it to 49. Now, my zones would be (RHR = 49, MaxHR=180, HRR=131):

Fat Burn: 101bpm-126bpm
Cardio: 127bpm-159bpm

Peak: 160bpm+

This will depend on your age but the zones shouldn't be very different. For the fat-burn zone and RHR between 40-49, the shift with incrementing the RHR is about 5bpm for the zone (using Fitbit formula). In other words, you should have no issues with reaching at least the fat-burn zone and earning AZMx1. With HR 140-150 you should get some AZMx2 as well.

My bet is that your HR tracking fails but I do have not enough data to analyze it.