Heart Rate Zone, Custom (one zone)

d_thomas02

Anyone using this setting?

I like the three zone graphs I get with the default setting, but my max heart rate is higher than "normal" for a man my age (56) so most of my cardio workouts are showing a 'peak' heart rate zone. I've just switched to the Custom one zone setting (130 to 161) and was wonder what to expect on my graphs.

Here are my heart rate zones as figured by http://www.digifit.com/heartratezones/training-zones.asp

d_thomas02

Did more research and found out that using the Custom heart rate zone does nothing for the graphs.

The only way to get the heart rate zones on the graphs to reflect my personal 'custom' numbers is to lie about my age. I had to change my birth year in my FitBit app from 1959 to 1985.

That's messed up.

heybales

Yes - because that will now mess up a whole bunch of other stuff.

It changes your BMR - and that means your daily activity burn is messed up.

It changes the estimated VO2max that is used to then estimate exercise calories - so that is messed up now.

There is no good way to turn the Fitbit HR devices into a full featured HRM setup.

About only way to get near to what you want, is to pick the one HR range you want, and set it so your vigorous workouts should always be above the top number, your recovery days below the bottom number, and your aerobic days within the range.

Considering there are no HR alarms anyway, which any decent HRM would have - that should allow for decent review.

heybales

Oh, on my profile page - the Weight Loss calculator - the HRM tab.
Fill in stats you know, use guidelines below for others, then section on HR zones to use.

Pick the Aerobic HR zone to use as the 1 zone on Fitbit - intense workouts would then be in Tempo zone, and recovery in the Active Recovery HR zone.

The formula uses the Karvonen method which is good, but with your estimated HRmax, not calculated on 220-age.

d_thomas02

heybales wrote: »

Yes - because that will now mess up a whole bunch of other stuff.

It changes your BMR - and that means your daily activity burn is messed up.

It changes the estimated VO2max that is used to then estimate exercise calories - so that is messed up now.

There is no good way to turn the Fitbit HR devices into a full featured HRM setup.

About only way to get near to what you want, is to pick the one HR range you want, and set it so your vigorous workouts should always be above the top number, your recovery days below the bottom number, and your aerobic days within the range.

Considering there are no HR alarms anyway, which any decent HRM would have - that should allow for decent review.

I saw the repercussions of the changed age by the end of yesterday.

Not looking for HR alarms or any other sophisticated features. Just want correct zones on my graphs after the workout.

Current plan is to keep my correct age most of the time while using the custom 1 zone. Then, just before looking at graph, I change my age to get the correct peak, cardio, fat burn zones to show on graph and immediately change back to correct age when I done. A clunky work-around but should be functional without screwing everything else I like about the FitBit.

I'll take a look at the calculator you mentioned.

Thanks.

d_thomas02

Still looking for a way to "fix" my FitBit heart rate charts.

Saw a work-around on the FitBit forums that claims FitBit uses the Mifflin-St Jeor equation to calculate BMR:

BMR = 9.99*weightKg + 6.25*heightCm - 4.92*ageYears + s

where s is +5 for males and -161 for female

Using my actual stats;

Sex: Male
Height: 70 inches or 177.8 cm
Weight: 208 lbs or 94.5 kg
Age: 56 yrs

FitBit calculates my BMR as 1785 calories.

Changing just my age to get my correct max HR messes up this calculated BMR, yes,...

BUT, if I also change my height to readjust my BMR back to the correct value (and then manually enter my stride length to keep FitBit from adjusting that due to my "new" height), hopefully, I get correct heart rate ranges on my charts without messing up everything else.

So,

my measured HRmax is 191 bpm.

Using the 220 - age = HRmax equation and reworking it to age = 220 - HRmax I get a theoretical age of 29 yr.

Now reworking the Mifflin-St Jeor equation to give a theoretical height for that theoretical age that keeps my BMR on the straight and narrow.

TheoreticalHeightCm = (BMR - 9.99*weightKg + 4.92*TheoreticalAgeYears - s) / 6.25
TheoreticalHeightCm = (1785 - (9.99 * 94.5) + (4.92*29) - 5) / 6.25
TheoreticalHeightCm = 156.5 cm or 61.6 inches.

I am now a theoretical 5'1.6", 208 lb, 29 year old man with a 2'5" walking stride and 3'10" jogging stride. [Yikes!]

heybales

Yep, when you mess with height, must use a manual stride length measurement.

But otherwise totally valid method for getting them to use a more accurate BMR figure too.

Like if you had an RMR test, or a good bodyfat % test and have better calculated Katch BMR - then adjusting the height forces Fitbit to use that better figure.

The Fitbit tab in that spreadsheet does exactly that.

The only caveat to that is the use of age in estimating a VO2max figure to use in estimating exercise calories based on HR, and BMI used in that too.

You'll notice on that HRM tab the method that Polar and Garmin both use to help estimate VO2max - and it involves age and BMI, so there's weight and height again.

What you might do is after a few exercise session - compare what Fitbit said calorie burn was compared to the HRM tab with your specs filled in - near the bottom is that ability.
Though Step 4 near top will also let you adjust figures, and to the right see the effect on calories burned in the formulas. May not matter much at all.

d_thomas02

Thanks @heybales, I'll do that.

RunRachelleRun

I tried that as my max heart rate is much higher than the standard calculation they are using. I became 20 and 4'10" or something (can't quite remember - may have been even smaller) with a manual 2'9" stride LOL.

The calorie burn during runnung or walking became quite inaccurate despite the more accurate heart rate zones. I went back to my actual settings: 42, 5'8".

I have noticed that while FitBit gave me a far higher burn the first month I had it, likely because of my higher working heart rate, it has since adjusted itself and even gives me a lower burn on occasion than my chest strap now. Overall, after the second month it is much more accurate.

For example, it used to be 100-150 calories over my chest strap for a half hour run despite a heart rate reading an average of 10 beats lower than my chest strap. Now it still gives an average lower heart rate, though does come close to spotting my max, but will often be slightly under the calorie burn of my chest strap.

So ... If you haven't had it very long, maybe just give it time to see if it also adjusts once it gets to know you. I can't understand how it is possible, but it seems to have recognized I am not average and adjusted itself for me.

heybales

It is using some standard methods that Polar and Garmin use - which involves resting HR, BMI, age, and calculated HRmax (so that inaccuracy is only part of the equation), and weekly exercise amount.
And restingHR and weekly workout time takes some span of time to improve the figures. And can change.

So indeed the calorie estimate can be as good as you can get without actual VO2max test and formula based on that.

But Thomas is going for HR zone training and review as the goal, not improving the calorie burn estimate.
He's trying to work around the fact Fitbit sets up their multi-zones based on calculated HRmax, with no user adjustment.

It's almost too bad they won't figure out some formula (never seen one in research) where if a certain HR higher than calculated HRmax is reached for say 1 min, then change HRmax to about 5-10 higher.
Any improvement to that has got to be better than keeping a figure that is obviously wrong because you've gone above it, like in your case.

RunRachelleRun

I am also working out using zone training, and I would prefer that Fitbit shows me my proper zones after each workout. I had a V02 max lab test to find out my correct zones; they are closest to the Zoldaz formula when I tried OPs link above, but still off slightly.

I was simply sharing my experience of the downside to making all those adjustments in order for Fitbit to show your proper zones. If you prefer to see how much time you spent in each zone after your workout and don't care about getting an accurate calorie burn, then it probably is worth it to adjust all the settings. But I still use a chest strap hr monitor for my workout, which gives me alerts to stay in the zone I choose, so getting a more accurate 24-hour calorie burn from Fitbit is more important to me. I thought it possible that @d_thomas02 might be in the same boat.

d_thomas02

@heybales is correct, @RunRachelleRun. At the moment, I'm more interested with heart rates and since I don't like wearing chest straps, my wrist HRM will do just fine.

Calories will take care of themselves over the long run by watching my weight trends.

Thanks for your input.

RunRachelleRun

Sorry, I wasn't trying to take your post off track. I get it now. I also just saw that you wrote you didn't mind switching it right before each run. I might try that myself. Though it might be hard to remember to switch it back. Ack.

I'll have to remember to email Fitbit and ask them to offer a better custom option. Maybe if enough of us ask, they'll offer it in a future update.

d_thomas02

The request to have a manually entered max heart rate had been made for over a year and continues to be requested over and over. FitBit has the request now under 'review'... and has continued to review it for about the same amount of time.

The work-around I gave above was from the users on the FitBit site.

d_thomas02

Her is a link to the request for a manual max heart rate.

https://community.fitbit.com/t5/Feature-Requests/Need-for-manual-max-HR-designation/idi-p/652703

Request date 01/26/2015
Reviewed date 03/30/2015

Only 27 votes, so if you'd like to see this request gain momentum, please add your vote.

heybales

Done. Hope they don't check what device I have (Zip).

d_thomas02

Saw the comment you left on the request page @heybales, thanks.

But the vote counter still shows only 27. If you go back to the site and click on the thumbs up icon, you'll see the counter increment.

heybales

Dooohhhh!

Someone else posted ditto's too - and it appears missed that vote too.

d_thomas02

No worries.

I wonder about creating a 'Feature Request' sticky. With links like I gave above.

If even 1% of the members of this group voted on a feature... Wow!

RunRachelleRun

Thanks for the link. I voted and posted a comment request. There was another link in the comments to a similar feature request and that one had 200 votes. I imagine the request would need more votes for them to take interest. Great idea to put a link(s) in the announcements for others to go vote.

d_thomas02

I saw that one too. While a manual max heart rate was mentioned, the main request was for more than three levels.

Heart rate zones: more of them, all editable (217 votes)

Another about max heart rate,

Auto adjusting maximum heart rate (11 votes)

And my personal favorite,

Waterproof (908 votes)

FYI, there is a third-party company that can water-proof your FitBit (if your model isn't all ready) or sell you one that has been water-proofed so I don't know if FitBit will ever offer a water-proof version of all models,

WaterFi

(I'm not endorsing WaterFi, just an interested owner of a FitBit Charge HR considering their water-proofing services.)

d_thomas02

Sorry, wrong link for Heart rate zones above.

Heart rate zones: more of them, all editable (217 votes)