Heart rate questions

Hi all! I have been having issues with my heart rate, and wondering if anyone else experiences the same things, or has any insight!

35 y/o female who is active.

My resting heart rate is low, anywhere from mid 30s sleeping, to 45-50 when awake. I’m convinced I hibernate each night :slight_smile:

However, when active, the heart rate spikes high and FAST. Last night, for example, I went for a fat bike ride - 45 minute total ride, with 43 of those minutes in zone 5, which is 180 or above. During the ride, I felt completely fine, not overly exhausted or working too hard. It was nice and mild out, I didn’t have to overexert during any of the ride, and I actually felt fine breathing (usually that’s where I struggle). After exercise, I usually get palpitations for a bit before everything goes back to “normal.” This seems to be what happens during any form of exercise for me. Riding TR, I do find myself working harder, which is the whole point of it :-), but my HR acts the same - spikes fast and quickly. If I hit 190, I stop until I get down to 175, and start up again. I’m just paranoid of something exploding inside of me. :smiley:

I just did a nuclear stress test last week, and the HR did act that way during the test (I made it a whopping 10 minutes on the treadmill - runners, I do NOT know how you do it!). Scans turned out fine, aced the stress test, no concerns from doc. Only thing noted was possible left atrial enlargement.

Am I a freak of nature? Should I get another opinion? I have a 100 mile ride in March, and I want to make sure that ride is not my last! Suggestions?

Thank you! Ride on!

1 Like

I m not a doctor nor a trainer. Just a training enthusiast. I’ll provide some reference articles for you and you can go from there.

First, heart rate is different everyone and your max heart rate cannot usually be accurately calculated by old, general rules of thumb. You may have a very high max heart rate, so your zones need to be determined accordingly through measurement. Then your work zones and heart rate zones can be more effectively determined. Also note that the boundaries between zones are not actually exact nor well defined. The training you do in each zone changes the size and boundaries of each. Do more endurance work and your endurance zone will get bigger and your endurance HR zone will likely move downward.


Next, it’s worth spending a little time to understand how your body works to generate pedal power so that you can be more specific about creating training adaptation. Once you know your physiological strengths, you can work to improve other aspects.


Armed with a better understanding of yourself and your physiology, you can set out to make changes through training. My enthusiast opinion is that you are blessed with a heart that beats fast, but likely could benefit from training it to beat more strongly and with fuller chambers of blood to increase your oxygen delivery. (Don’t we all need this?). Beating fast is good, but as detailed below it generally means that your heart beats in little squirts with less then optimal oxygen in your blood.


(This is my simplified version of the EFR articles)

I am by no means an expert and not really that informed on this topic, but I have read these and other references in my own quest to train better. Happy to share and discuss.



My suggestion would be a stress test, which youve done and had no issues. As long as your cardiologist isnt concerned, you shouldnt be either. A second opinion isnt going to change anything. Your results are your results. Could maybe follow it up with a lactate/vo2 test to set your HR zones correctly? That said, 180 is up there regardless of how you calculate your zones

Strange that you can hang out in Z5 that long and bounce back quickly. Is there any chance your HR meter is crap? To answer your question, yes, if you can hang out in Z5 for 43 minutes and bounce back, you are indeed a freak of nature!


(Similar disclaimer to Juarez. I’m not a doctor just a nerd with an interest in physiology)

There’s nothing inherently bad about having a responsive heart rate. Conversely, having a heart rate that doesn’t respond is a problem (that you don’t have at the moment, to be clear). The palpitations are a concern but it sounds like you saw a cardiologist already.

A couple suggestions to try:

  1. 43 minutes in zone 5 out of a 45 minute ride implies that you didn’t warm up (much). The aerobic system takes a bit to get into gear. Without warming up your anaerobic system will be providing more of the power than it otherwise would at that intensity and that’s something which your body will try to recover from later on in the effort making it more of a stress than it’d otherwise be.

  2. Anxiety can increase heart rate on its own and if you’re anxious about having a high heart rate than it’d create a bit of a feedback loop. You could try a few TR rides with the heartrate display turned off and compare them to similar rides with the display on.


With very similar disclaimers to those above, this may be part of the issue.

I am an anxiety sufferer and have had some cardiac ‘issues’ in the past (ultimately all cleared by testing). I have discovered that my anxiety tends to physically manifest in higher HR and feelings of erratic heartbeats. I still get concerned about it from time to time but reassure myself that I have had extensive tests, and (in the words of my wife, who is a medic) have ample evidence that my heart actually functions extremely well.

If your doc isn’t concerned - and I assume you asked him directly - then you shouldn’t be either. It may be worth asking him what he thinks is going on, however.

I would also recommend borrowing a second HR monitor. One of the things that caused my initial referral to a cardiologist was my Fitbit recording sleeping HR spikes of 180+, often for 30 minutes plus. It was only when it did the same in my kitchen, while I was standing cooking, and I manually recorded my HR at c.65, did I realise that there was a tech issue.

Good luck.


From what you wrote, its really hard to say anything other than you completed a nuclear stress test and got a clean bill of health.

Unfortunately heart rate can be highly individual, and you didn’t say how you determined HR zones and your level of confidence in those HR zones. As mentioned by others, the HR measuring device can also complicate things. There are good/bad chest straps, HR monitors worn on bicep, HR monitors on the wrist, etc.

I’ve been having the same issue. I have resting in low 50s upper 40s. However, my max is 203. For the longest time I was using the age minus calculation which I found to be inaccurate for me. If you do the Ramp test properly, you should find out what YOUR max is and, with that, what zone 180 actually is.

I had a cardiologist do a stress test which showed about 205 and then the Ramp test showed 203. The cardiologist simultaneously ruled out any heart issues. This is what I advise. Better to be safe than sorry and dead.

Here I have been thinking 180 is way to high when in fact it’s not for me.

1 Like

FWIW I’ve never hit my max heart rate on ramp test, but came within 3bpm at 172bpm. Always hit 175-176bpm after riding for 1+ hours, then doing 5-10 minutes above threshold and finishing with an all-out sprint - usually Wed Worlds although some are other hard group rides.

In general, coaches are in agreement that a long threshold effort should be used to set HR zones. Friel suggests a 30 minutes all-out time trial and use the last 20-minutes as your lactate threshold heart rate (LTHR), and then set zones using that. Similar with Coggan. My threshold based HR zones have delivered highly productive tempo, sweet spot, and threshold workouts since setting them up in late 2016. And unlike FTP, the HR zones barely change (trained vs untrained), so it is a great way to restart endurance rides after taking a long break.

It’s worth noting you need to be fresh if you’re testing to find zones. I won’t get above 178/179 with a gun to my head when I’m at the end of a block, but will hit 8-10 beats higher when rested.

1 Like

This stuff is confusing.

In Garmin connect, for my Epix watch, for cycling, there are two HR settings. HR max and LTHR. I set the HR Max to my actual max and Garmin calculates the HR zones based on that, not the LTHR. My understanding is that the LTHR will be less than the HR Max.

So this leaves me wondering, if zones should be set based on LTHR, then why is Garmin calculating zones based on HR max?

Hmm, I’ve got a Garmin 530 and mine are configured as % LTHR:

FWIW I started with Friel and its a simple yet intimidating test: Joe Friel's Quick Guide to Setting Zones | TrainingPeaks but Wed Worlds required riding for 40-min at threshold so I built up to it by doing Wed Worlds for 8 months.

1 Like

I see. So there’s a choice in which to use for the calculation. The next question is how to determine which to use? Which has more scientific validity I guess?

I picked mine based on “the coaches I respect recommend LTHR” and like I said it works really well and gives me highly productive workouts after taking time off.

Thanks for this new information that I missed. I guess I will try both for a bit and see what works best for me.

Sorry if i hijacked the thread a bit.

1 Like

Coggan said this in the 2003 presentation to coaches:

“HR guidelines: Relating or translating the specified power levels to corresponding HR ranges or zones is somewhat difficult, due to the inherent variability of HR as well as individual differences in the power-HR relationship (even when referenced to threshold power). Nonetheless, approximate HR guidelines have been provided in Table 1, such that they can be used along with power to help guide training if desired.”

my variability is low, and related to outside temperature, so it really comes down to individual differences “even when referenced to threshold power” so my solution was to do long-term trending and individualize my HR zones.

I can’t comment on the health risks for you associated with exercise. But you’ve already been to a doc for a stress test - so presumably that alleviates concern there. If you’re not convinced, go for a 2nd opinion.

Heart rate response to exercise depends on what kind of exercise you are doing (and also characteristics of each individual).

Have you mapped out how your heart responds to specific kinds of exercise? Eg, how does your heart rate respond during the following:

  • Ramp test
  • 1hr at steady endurance pace eg 65% of FTP
  • 1hr at high tempo/low sweet spot eg 85% of FTP
  • VO2max intervals eg 6X3 at 120%, with 3 min rests

It would be highly unusual for your HR to behave the same way across these different kinds of exercises.

For me, my HR responds in a pretty predictable way on the trainer.

When riding outside, and in particular during MTB races, I can get odd results. Eg a race this year with heart rate at 95% of max for 1.5 hours*.

So when doing the above tests, best to do them in a controlled environment like on a trainer. Also, make sure you have a reliable way to measure HR. A chest strap is best.

-* High heart rate throughout, even on the descents

1 Like

Thanks so much for these references!

1 Like

Freak of nature it is! :smiley: I just bought another HR monitor, as my four year old wrist Garmin was starting to make me REALLY feel like a freak of nature (125 bpm when I was working my tail off…I knew THAT wasn’t right!!). I now have a new Garmin chest strap, and it seems to be pretty accurate. Thanks for your reply!

This is very important. I assume you have told your doc that you are an active athlete, training regularly, correct? And that it was ok for you to continue training the way you do, correct?

Assuming the answer is yes to both, then I think you are in the clear: even though your heart rate is unusually high, you feel good (!!) and your doctor has given you the green light.

Given that you have had yourself checked out by a professional, I don’t think this is necessary. Just ignore heart rate if it makes you nervous. TR allows you to toggle the heart rate field on and off. (Heart rate is still being recorded.)

Some people have unusual heart rates, and it doesn’t mean they are more or less fit. I sometimes see people with a heart rate of over 200. If that were ever to happen to me, I sincerely hope I’d have a cardiologist by my side and am hooked up to medical equipment :wink:

Out of interest, do you ever do easy rides ( low RPE) ? If so what does heart do?

Is your HRM a strap or watch?