Peak heart rate zone

[SonnyCorleone]

For how long can your heart beat at peak rate before damage is done?

[shipo]

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@Mykaelous wrote:

Hmm just did 1.5 hours at 186 average heart rate. Woke up a bit sore the next day.

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Wow, what were you doing for that hour and a half?

[Judi_WA]

Do you think that the Fitbit accurately records your heart rate? When I run it always says that I am in my peak heart rate zone but I can talk the whole time so I just don't believe that it is accurately recording the heart rate. You can't talk in Peak...right?

[Heybales]

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@Judi_WA wrote:

Do you think that the Fitbit accurately records your heart rate? When I run it always says that I am in my peak heart rate zone but I can talk the whole time so I just don't believe that it is accurately recording the heart rate. You can't talk in Peak...right?

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So you trust the HR zone is correct, but the HR may be wrong?

Why is that?

Do you know what the HR zone is based on?

So you think the HR reading is higher than reality.

Pretty easy to test the accuracy of the HR reading - put your finger on your neck or wrist, or shoot if exercising can probably watch a beating vein/vessel and count for 15 sec.

[shipo]

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@Judi_WA wrote:

Do you think that the Fitbit accurately records your heart rate? When I run it always says that I am in my peak heart rate zone but I can talk the whole time so I just don't believe that it is accurately recording the heart rate. You can't talk in Peak...right?

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Yes, I do believe Fitbit trackers accurately record heart rates when worn correctly; the lone exception being the first few minutes of a run with the new Ionic which seems to spike the recorded rate (it has been theorized this is due to a lack of moisture between the back of the tracker and the skin).  That said, I believe the so called Heart Rate Zones are as often incorrect for any given individual as they are relatively accurate.  Why?  The thing is, the whole 220-Age formula promulgated by everyone from the American Heart Association on down is a bunch of junk.  The formula is based on a very wide spectrum of averages which do not necessarily apply to any given individual.

In your case, given you can cruise along in the peak zone while talking the whole time (I too fall into that category) implies you have a much higher max heart rate than the above mentioned formula would suggest.  In my case I'm 60 so the formula predicts my maximum should be 160, yeah, about that, I routinely see my heart rate get up into the 170s while running up a long steep grade, or when hustling as fast as I can to the finish line of a long race.

What do you do about it?  Simple, go into your settings and change your max heart rate to something more reasonable; I changed mine to something like 182.

[Corney]

Judi_WA You can talk at your peak HR if you have greatly improved your
aerobic capacity. The talk test relates to your ability to talk while
exercising, if you are able to talk then you are taking in enough O2 and
able to use it so as not to develop an O2 debt thereby working
anaerobically. I can talk when exercising in my peak zone.

[Heybales]

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@Corney wrote:
Judi_WA You can talk at your peak HR if you have greatly improved your
aerobic capacity. The talk test relates to your ability to talk while
exercising, if you are able to talk then you are taking in enough O2 and
able to use it so as not to develop an O2 debt thereby working
anaerobically. I can talk when exercising in my peak zone.

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Well - you may have your HR indeed beating in a zone that is calculated based on some rather simple formulas - and called the Peak Zone.

But as that Zone is literally in the top 10-15% of HRmax (not calculated, reality here) - then you being able to talk in it doesn't mean you are fit - it means the zone is incorrect.

Peak HR zone would specifically mean you could NOT talk normally when exercising in it.

That would be the aerobic zone, if long sentences the bottom of it, if brief words the top of it.

If you were doing a specific workout plan involving HR for making some sort of improvements (Peak would be for lactate uptake and endurance), and needed that Peak Zone to accomplish it - then the Fitbit estimated zone would be incorrect and you would not get your desired effect from the workout plan.

Same as if you were to do workouts in the Aerobic Zone for a purpose, you'd actually be well below it.

Not because of fitness, but because of incorrect zone estimated HR's.

That's the thing with the zones - as fitness improves - the zones shift up in reality.

[Corney]

Heybales: Fitbit calculates it's various zones based on age, which I agree
is very simplistic. She asked if her Fitbit zones were correct if she
could still talk in her peak zone. I agreed., not only because I can
comfortably talk when I'm exercising in my peak zone, but also because
improved aerobic fitness allows more work to be accomplished aerobically,
in the absence of lactic acid because anaerobic thresholds are raised. What
I'm saying you should pay less attention to Fitbit zones and more attention
to your body and what it's telling you. If you can comfortably talk while
exercising you are still in your aerobic zone, and as your fitness level
increases you may still be in your aerobic zone even though your Fitbit
puts you in your peak zone.

[AndyZB]

This is a very interesting discussion and I am surprised that an MD - of which many wear fitbits and probably subscribe to the community - have not chimed in. 

The bottom line is that the formulas - all the formulas - are flawed. The heart is a muscle. And, while it is different than skeletal muscle, it shares many similar behaviors with other muscle groups. No one pays attention, for example, to the formula that says that you should bench press your own weight. Intuitively, we understand that people are in very different physical states of fitness. Imagine if everyone tried to press their weight! We'd have a bunch of people hurt very quickly!

The same applies to the heart. Not all 47 year old hearts are the same. People who have trained all their lives will have resting heart rates in the 40s and 50s, peak at 190s and have recovery times of a minute or less. They will be able to sustain HR close to peak for extended periods of time.  Conversely, someone of the same age, height and weight who is not in good shape will peak at 180, will only be able to sustain it for a few minutes and recover much slower. 

The bench press analogy is not perfect. Going above your max in bench press would simply not allow you to lift the weight. As many have said, the heart has its own protection systems: other muscles will starve of oxygen long before the heart will. 

[shipo]

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@AndyZB wrote:

This is a very interesting discussion and I am surprised that an MD - of which many wear fitbits and probably subscribe to the community - have not chimed in. 

The bottom line is that the formulas - all the formulas - are flawed. The heart is a muscle. And, while it is different than skeletal muscle, it shares many similar behaviors with other muscle groups. No one pays attention, for example, to the formula that says that you should bench press your own weight. Intuitively, we understand that people are in very different physical states of fitness. Imagine if everyone tried to press their weight! We'd have a bunch of people hurt very quickly!

The same applies to the heart. Not all 47 year old hearts are the same. People who have trained all their lives will have resting heart rates in the 40s and 50s, peak at 190s and have recovery times of a minute or less. They will be able to sustain HR close to peak for extended periods of time.  Conversely, someone of the same age, height and weight who is not in good shape will peak at 180, will only be able to sustain it for a few minutes and recover much slower. 

The bench press analogy is not perfect. Going above your max in bench press would simply not allow you to lift the weight. As many have said, the heart has its own protection systems: other muscles will starve of oxygen long before the heart will. 

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By in large I agree with you, but you seem to be missing a proven medical point; maximum heart rates at any given age are NOT a function of conditioning, they are a function of genetics.

[Referee852]

It would be useful if a few MDs would comment on the interesting posts already on this topic.  For the record, I am aged 62, about 3 stone over-weight and have had a fitbit for about 2 years.  My son recently bought me a new Fitbit Charge 2 so that I could monitor my heart rate.  I was quite surprised that my resting HR, during sleep, is around 42 to 48 (unless I have had a few drinks or red wine, when it seems to be about 50 to 54).  During my exercise when I do a 40 to 60 minute run (outdoors or indoors on a treadmill) my HR peaks early at about 160 ie in the first 8 mins or so and then it oscillates around 142 for the duration of my run.  Historically, I used to run about 50 miles a week for about 15 years but over the last 4 or 5 years have done very little (hence the weight gain).  back in training now and hoping to shift the excess weight.  The formulas don't work for me because, which ever one I use, I seem to be able to run easily at peak for quite a long time.  I do recall using a HR monitor when I was around 40 years old (they were useless most of the time so didn't use them often) and my training pace was about 130 which was more realistic.  I have no medical experience but I believe max HRs are mostly linked to genetics and there is also a  correlation due to fitness levels which will impact upon the actual figures an individual can attain.  In a similar vein, resting HRs are also a hot topic of conversation.  You can read literature that states if you have a resting HR of say below 50 you are in the highly trained athletic zone.  Then an individual will comment that his rate is 46 and that he never exercises and smokes 20 **ahem**s a day.  So please MDs give us the benefit of your professional expertise?      

[nts]

My doctor told me the same. I' m 64, peak heart rate at 150-170 for 30 mins (according to my Ionic) on elliptical, and I don't feel that tired. The strange part is it varies up to 20 with the same duration and type of exercise.

I'm also a little concerned whether there is any harm.

[Heybales]

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@nts wrote:

My doctor told me the same. I' m 64, peak heart rate at 150-170 for 30 mins (according to my Ionic) on elliptical, and I don't feel that tired. The strange part is it varies up to 20 with the same duration and type of exercise.

I'm also a little concerned whether there is any harm.

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If that is indeed an accurate reading, and likely is since people that see inaccuracy usually don't read that high - that would be considered your aerobic zone.

To tweak your zones you could mess around with the HRmax figure in your settings until the aerobic zone had 170 as top end. Unless that seems like easy effort at 170, in which case 170 could be middle of your aerobic zone.

As to it varying between the same workout intensity - you have nailed exactly why HR-based calorie burn can be very in accurate.

There are many reasons for HR to vary that has nothing to do with the intensity of the workout and therefore need to supply oxygen.

There is called HR drift where merely doing a long say 60 min exact same intensity (pace on treadmill say), causes the HR to slowly rise the whole time.

Well, the workload has stayed exactly the same, so it's not beating faster to provide more oxygen because you are burning more fuel for harder workout.

Then there is dehydated elevated HR - heart is just pumping faster to get the thicker blood to move to carry the required oxygen for that workload.

Then there is heat elevated HR, merely to aid in cooling the working muscles better, and get blood up to surface of skin for cooling effect.

Then there is stressed elevated - meds, caffeine, fear, prior hard workout (like lifting) - just beating faster.

Some meds can cause slower HR, but then since body can't supply enough oxygen for a certain workload - you also can't move as fast then.

So most reasons cause elevated higher than actually needed purely to provide oxygen to oxidize fat and carbs for energy - which is what the calorie burn formula using HR are based on.

Usually you can get good at recognizing what cause was the reason for a workout having higher than normal HR.

Be wary of calorie burn then if it was a big jump up, and a long time.

[Pfg23]

Thanks for this discussion. I’m 70 y.o. Female training for walking Half. My HR stays in the red for most of my walks, but lower than peak. Last 12 mi, I wore out at 10! Looking back I started out too fast, didn’t carb out the day before, didn’t hydrate enough...what other mistake did I miss?😄 Oh and it was hot and humid (Florida Keys). 

[Kiasmama]

Hmm, I've never really paid attention to heart rate zones. I just run, when I am tired I slow down. I run for 20 mins about 5 miles an hour. I"m out of shape, and I am in my peak for 6 mins usually according to fitbit. I am tired, but not exhausted. So why should I worry? I'm being serious about asking. I figure the body will tell me when I need to slow down. I can't see me being able to damage my heart in anyway. Isn't working out, building up time and miles, helping "build up" the heart as well-since it is a muscle. 

[rockpool]

Very interesting discussion!

I am 73, and during my daily 40 min. exercise walks with my bungy pump poles (https://www.youtube.com/watch?v=iS642PecP38) my Fitbit regularly records quite a lot of peak zone (up to 60%). And I can easily talk during the whole sessions. I work up a transpiration, but never exhaust myself. Today I peaked at 171 which was the highest so far. 

When I first started on these walks a year ago, the zones looked very different, and I usually peaked at something like 120-130, but only for quite brief moments, even though I worked just as hard. 

My personal conclusion has been that my HR zones would now probably need to be adjusted due to better condition and higher max heart rate than a year ago. 

[SunsetRunner]

One thing, I think, worth mentioning is that Fitbit unlike other trackers and apps recognizes less zones. In my case, I exercise pretty much always in the peak according to Fitbir while with use of other trackers and HR monitors, most of the time ( if I not try harder ) I stay in Moderate or whatever that range is called. In most of implementations there are 5 zones not 3 so it isn't so easy to hit the peak 😉

[Pfg23]

Without medical backing, but just based on my personal experience, I would
agree.
--
Pam Greenman

[Emmajayne07]

Working in hospitality it's not unusual for me to spend 10 hours between 160 and 190. Also a touch sore the next day but when you work 5 days a week you dont have much time for that

[Heybales]

@Emmajayne07 

Curious if you have ever confirmed that HR with second hand and 10-15 sec of actual artery beats counting?

Perhaps that's where your figure comes from anyway, but since this site is for devices that have HR monitor built in, wanted to ask how you got the count.

Because that is a rather high HR for something you spend a lot of time doing - normally when you do something for a long time your body becomes better adapted at doing it at the same intensity, so HR would lower in the case of an activity like that - basically endurance.

So either you have remained a tad aerobically unfit and so HR has to be high for that activity level, or the Fitbit is misreading the HR when it goes high but it's not really that high.

Or you have spikes up and down and while that is an average that is understandably inflated higher (interval type activity causes a higher avg), it still sounds high.

Many have shown their Fitbit has issues when the HR goes up just a decent amount into exercise zone, which that industry sure would - but the accuracy is lost.

If the 07 in your name is your birth year and only 12 yrs old - then I take it back. Though now I wonder about child labor laws ... 😉

[geekchorus]

I think I've read all the replies and not one addresses the fact that the age-based formula mentioned here, and used by Fitbit are not appropriate for certain people. My husband and I are 69 ad 64, for example, have average daytime resting heart-rates at 50-52 BPM. When we were younger our resting heart rates were even lower. We've never been professional or even elite athletes. The formula used by fitbit DOES NOT WORK for people outside the average range. Actually, for everyone, this Mayo Clinic page gives a much better way to calculate your heart-rate zones at about half-way down the page: 

https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise-intensity/art-20046887