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Resting heart rate. What it is and what information it provides.


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The resting heart rate is not a new fact, it has been with us for many, many years, and it has never been difficult to know, you simply had to take your heart rate as soon as you got up, and we didn't even need any devices. It was as simple as taking your pulse by putting a finger on your wrist, as you were probably taught to do at school (at least I learned how to do it there).

But with the numerous arrival of watches equipped with optical pulse sensors, capable of taking pulse data over 24 hours, it has become more relevant. These devices allow not only to record your heart rate while you are doing sports, but also while you are travelling in the metro, drinking a beer or working (yes, also when you are doing THAT... you know what I mean).

This is when your doubts start. Is this information useful? What can I do with it? What is the use of knowing my heart rate at rest?

So since you have questions, I have answers. Let's go with them!

What is a resting heart rate?

The resting heart rate is the lowest number of beats per minute that you have while you are awake and at rest. It is not, therefore, the heart rate while you are sleeping, which is usually much lower than usual.

Usually the best time of day to take your pulse and know your resting heart rate (also known as RHR) is in the morning, right after waking up and while lying in bed.

Garmin Resting Heart Rate   Fitbit Charge HR - Pulse tracking

If you want to keep a constant record of your RCF over different days, you should always take it in the same condition, so before you get up to drink your coffee, remember to take your pulse so you can write it down later.

What is the purpose of knowing your resting pulse?

Your resting heart rate is one of the best indicators of assimilation of training. When your resting heart rate decreases as a result of training, it is a sign that you are improving your aerobic capacity (because you are increasing the size of your heart). But above this, monitoring your HRF will help you to know how much fatigue you have accumulated and when you might be too tired, knowing whether you should rest or whether you can hit it hard during the day's training.

For this it is necessary to control our pulse at rest and, as I say, always do it in the same conditions so that the data is comparable. The importance is not in a specific data, which by itself is not worth anything. If today you take your heart rate at rest and it gives you 55 beats per minute, what do you do with the data? Nothing, because without being able to compare it with something else it does not tell us anything.



The value of all this is the daily record and therefore the trend over time. This is when we can know more about our physical condition, whether we are training well or if you are overdoing it, or if you are catching a virus or have a fever. To give you an example, I know that my usual resting heart rate is between 46-48 beats per minute. If I train hard, I also know that the next day my resting pulse will increase, hovering around 53-54 beats per minute. If I have been training hard for a week and I am in that range or slightly higher, I can also recognize that this is a normal state.

But if I'm not doing intensity training and my resting pulse goes up to that range or above, I can tell that something is wrong. It may indicate that there is an injury, that I'm about to get sick, fever, general tiredness or stress. By the time I get to 58-60 resting pulses I have to ask myself what can cause that rise in pulse rate.

What you should not do is compare your resting CF with anyone else's. You are a unique specimen, with a unique training and physical characteristics. Your fatigue partner's CF may be lower, but it is not indicative of anything or it may be for 20 different reasons. Remember, it is your tendency over time that is important.

How do you take your resting heart rate?

You know, the best time to take your RCF is in the morning in bed, as soon as you wake up and before you get up. You can do it the traditional wayby putting your fingers on your wrist and keeping an eye on a stopwatch. Although today there are technology cheap enough to automate that process a little bit.

If you're around, though, it's because you're interested in sport-focused technology. I'm sure you already have at least one heart rate monitor at home. You'll simply have to put the sensor on your chest, relax for a minute and see on the screen which is the lowest reading that appears while you're lying down. That will be the value you'll have to write down as your resting heart rate for that day.

Using optical sensors to have the pulse at rest automatically

Let's face it: we are very lazy. That the first thing we have to do in the morning is to take our RCF and write it down is not what you want to do as soon as you wake up. As always, technology comes to fill in the gaps. In this case, to compensate our laziness or to free our mind from one more routine task.

With the rise of optical pulse sensor devices, another function is to monitor the heart rate throughout the day, recording all these data and trends associated with our movement and rest. Of course, this includes recording our pulse at rest.

Garmin Forerunner 735XT - Instant FC

But if you've read this far, you'll remember that we agreed that the resting heart rate is the lowest register while you're awakeHow is a device able to differentiate between the periods of being awake and being asleep? This is where the issue (which until now was very simple) starts to get complicated.

Collecting data

It depends on the manufacturer and how he has prepared the algorithms specifically. Some will not differentiate the sleep period and simply look for the lowest register of the day. Others will forget the lowest value and look for an average over a certain time or an average of the lowest values of the day.

In the case of those who do average, we get back into somewhat swampy terrain. What's the refresh rate they have? I mean, how often do they take heart rate records? Some manufacturers have a fairly solid recording period, like Fitbit that does it every 5 seconds when you're not recording a specific sport.

Others go to the other extreme, for example the Apple Watch records the pulse every 10 minutes, regardless of what you do in that period of time. You can do an interval at 3:00 min/km going up to 185 beats per minute, which if you are not recording the activity, it may not be recorded anywhere. The reason is none other than not to impact the battery too much.

Garmin, for example, opts for an intermediate solution: varying the recording rate depending on whether there is movement or not. If you are not moving, it will extend the pulse reading range. If you are moving, it will shorten it. However, it lacks an option that allows us to decide for ourselves whether we want to sacrifice autonomy in exchange for greater precision in obtaining data. Garmin fills its watches with options and customisations, but sometimes it leaves the most elementary things on the table.

Therefore not only the accuracy of the optical sensor is important, but also the frequency with which it records data.

 Garmin Vivoactive HR - Synchronized HR Graphics

Devices that allow it

Today the list of devices that already allow to do this heart rate monitoring is already quite extensive, and what is about to come, because if a year ago optical sensors were becoming an option for the immediate future, most probably within a year all watches will incorporate an optical pulse sensor by default. All brands already have it in their catalog in one form or another, Suunto being the last one to arrive as it will have a Spartan Sport with optical measurement with Valencell sensor by the end of the year (although it is not clear if it will monitor pulse during 24 hours).

Garmin Forerunner 230/235 - Optical Pulse Sensor

As of the date of this article, these are the devices that support it. As I say, in the next months more models will be added to this list until it becomes something totally standard (do you remember when the activity monitor was a novelty?), so if you arrive here in five months and you don't find a device in the list, you can notify it in the comments and I will add it to the list (if I haven't remembered to do it before):

  • Fitbit Blaze
  • Fitbit Charge HR
  • Fitbit Surge
  • Garmin Forerunner 235
  • Garmin Forerunner 735XT
  • Garmin Fenix 3 HR
  • Garmin Vivoactive HR
  • Garmin Vivosmart HR
  • Garmin Vivosmart HR+
  • TomTom Runner 2

There are other smart watches like the Motorola Moto 360 Sport or Apple Watch that also incorporate it, but they go in a different direction from the type of product I usually deal with on the page.

These other devices, despite having an optical pulse sensor, do not offer constant HR monitoring. Whether or not they do in the future remains to be seen.

  • Adidas miCoach Smart Run - The sensor is of Mio (Philips) origin, and only supports pulse measurement during training. You will not receive constant measurement update.
  • Garmin Forerunner 225 - Identical to Adidas. With its Mio origin sensor the measurement during exercise is very good, but there is no possibility of measuring the rest of the day.
  • Polar A360 - Right now the Polar optical sensor does not offer this function, but the Finns have indicated that they will incorporate it.
  • Polar M600 - Identical to the previous case, although with a renewed sensor.
  • External optical sensors - I am referring to "passive" sensors that simply send heart rate data. That is, Mio products (Mio Link, Alpha, Fuseetc.) and Scosche RHYTHM+. They are not "smart" devices nor do they have memory capable of storing data, so even if the sensor would allow it, the device cannot.
  • Suunto Spartan Sport - At the moment the only thing we know is that the sensor will be from Valencell (same manufacturer as Scosche RHYTHM+) and it is not clear if it will support the function. So for the moment it will remain in this "not supported" section.
  • TomTom Runner Cardio - The first version of the Optical Sensor Runner featured an optical sensor from Mio. And as you've seen, there's no chance of it supporting it.

Remember that you can find all the information about the above devices and their optical pulse sensor in the test section of the page.

Use it to your advantage

Now that you know what you can do by knowing your resting heart rate and how you can do it, it's up to you to use it to your advantage. So, constantly monitor yourself to be able to identify what is normal and what is not and to be able to determine if it's a good day for an intense workout or if it's better to take it easy. Or even if you're on the verge of getting sick and it's better to keep warm.

Fitbit Surge - Widgets

You need an adjustment period. It is not by taking the data for three days in a row and then starting to make decisions based on the result on the fourth day. You need to record the data continuously to have a clear trend of what your usual minimum frequency is. Also be careful when you make a change of device or recording method (i.e. from the manual method to an optical sensor watch, for example), to assess how the change may have affected your daily recording.

And with that... thanks for reading!

Eduardo Mateos

I've been surrounded by electronic devices of all kinds for more than 25 years. Using them, testing them, taking them apart and dissecting them. Long distance triathlete: I swim, run and cycle for a long time. Maybe too much.

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  1. I also find the resting heart rate very interesting. I have a question to see if anyone knows, finger pulse oximeters measure your heart rate on the screen, right, but there is no one that records those measurements in a file with dates and heart rates to have a history, right? Someone who creates that history file and then you can extract it to have on the computer.

    Well two questions, I have a Garmin Fenix 3 compatible with Connect IQ applications, if I'm not mistaken third party applications are not allowed to write in files in the SmartWatch, right? Was there something that with the Connect IQ 2.0 version this was going to change? I say this because if not theirs could also be a Connect IQ application that in addition to showing you your heart rate at rest for n minutes also save that record in a history file in the SmartWatch.

    1. Regarding the first question, I can't give you much information. These types of devices exist, but they are more focused on medical use (with a price in line).

      As for the second, on the 10th the update was finally released with support for the new version of Connect IQ, which allows data to be recorded in FIT files.

  2. Hello, I have a doubt, my vivoactive HR at 0 hs where it should be restarted always counts with burned calories. For example, when I wake up in the morning I already have between 300 and 500 calories followed by the symbol of the fire, even when I don't have it on my wrist and it is charging on my pc. How can I solve this?

    1. It is the basal calorie intake, which is automatically calculated through age, height and weight. The calories it indicates are those of basal consumption plus those consumed in activity.

  3. Maybe it's not the right place for my doubt, but diving through the contents of the Blog (very good by the way!!), I'm in doubt...
    I currently have an activity bracelet (the mi band 2) that I bought for cheap, and to see if it goes with me about counting the activity and so on.
    The thing is that I like it very much, and I miss that having an iPhone I can't have a tapping during the day, but it's manual.
    The thing is that I train regularly (and I do triathlon, well, I participate in events... Hajajajajajajajajajaja) and I need something to keep up with me.
    To train I have a 920xt and a v800 (I'm a bit capricious, I know) so the train-competition part is more than covered.

    I hesitate between an Apple Watch, garmin vivomart hr or even the hr+ (although the sleep thing doesn't make it very there)... I loved the fitbit but... It can't get wet and I want to wear it always...
    Advice? How could you get your hands on almost all... Honest opinion?
    Because I see the Apple Watch as the ultimate toy, although it doesn't replace my garmin/polar in any way.
    I find the bracelets more useful because I can always wear them with or without a watch... But I'm a mess...
    What do you think?

    1. If you don't mind the expense and are looking for a smart watch, in that sense the Apple Watch S2 is, to this day, totally unbeatable.
      Although it seems to me an excessive outlay as a "toy" to measure daily activity, considering that you already have watches for training and competition.

      As for activity monitors, the advantage of Garmin devices is that they already synchronise activity with each other. You can wear an activity monitor every day and after synchronisation, the 920XT will show you the same step and calorie information.

      1. Hello!
        I don't know if I'm writing to you directly or I'm writing to the Blog... But well, I'm not going to tell intimacies so no problem ??

        You may think it's a little heavy, but I'm very hesitant...

        I see the utility of the garmin that I can use a watch at the same time if I want and continue counting the activity. Besides that it is compatible to share the FC and I see it as a tip. On the other hand, if you buy the plus version that has GPS, in trips or similar you would not need to take anything but the charger and you could do some session, perhaps more in conditions that with the Apple Watch?

        And I see the Apple Watch as more useful as a smartwatch than a watch that lets me train... And that doesn't let me export data throws me back quite a bit... Because I usually unify all training in strava. But it's not clear to me if the smartwatch functions compensate for the fact that it falls short in other areas.

        It's that in view of the investment... One for 160-170 euros and the other for about 400 and a little... It makes me think a lot. And with iOS... There are few that meet more, because the Pebble that was one of my main options, is out of support at the end of the year, and fitbit that I think is the best quantifier, as you say, incredibly, you can not get wet.

        Sorry to nag you so much... ?? And thank you!!!

        1. In principle, with the Apple Watch and the latest update of Strava you can export activities, but if you value it, let it be more for the possibilities of intelligent clock than for the training itself.

  4. Hi great job and very enlightening, I have a garmin 235 and I can't find anything as basic as an alarm that indicates too high a cardio frequency.

  5. The best way to monitor your heart rate at rest is with a pulse oximeter, which also monitors your blood oxygen saturation, another very good piece of information for monitoring your fitness level. It is a simple to use and economically priced device.

  6. Hi, congratulations on the blog. Despite having read quite a few device reviews I had not located this post...

    I have a question, see if anyone can answer it, about the RCF.

    I am a person with a relatively low pulse. During the day I usually see the pulse between 35-40ppm, even at certain moments less... although I don't know if it can be because of the optical sensor.

    The problem I see is that Garmin brand RCFs are always between 40-45, which is quite far from what I see during the day, usually when I am sitting at work without stress.

    I attributed this to the fact that my old device, not noticing movement, registered little data during the first and last hours of the night and at some period during the day, but when I changed to the new Elevate that always registers in the same time range, I see that nothing has changed...

    What is the reason for this variation between daily minimums and the Garmin branded RCF?

    Thank you!

    1. Each manufacturer configures the algorithm in a specific way... And they do it surely to avoid that if there is a too low punctual reading because of a wrong reading that will be shown as a resting heart rate.

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