Extremely high HR

So, something slightly concerning happened during my most recent VO2 interval workout… It was a running workout, but that’s mostly irrelevant to the question at hand.

I’m 36 years old… Generally my HR will climb into the 180-185 range during a VO2 interval. Every once and awhile, while reviewing my data after one of these strenuous workouts I’ll see a spike in HR over 200 which I’ve always attributed to the HRM malfunctioning… after all, historically they’ve been very short in duration and I haven’t noticed them until after the workout is completed while reviewing data.

My workout today was 12x400m… Everything was going great, but after the 10th rep I was curious and decided to scroll through the various data screens on my watch to check my HR… it showed 234 in that moment. I immediately assumed a malfunction (even though I’ve never had any problems with the HRM other than very short 1 second peaks) and manually checked on my neck. That’s when I became concerned… it was too fast to count; like crazy fast!!! I felt no worse or better than I would expect at this point in a workout like this, but decided to extend the break until it dropped to an acceptable level. When after a minute it hadn’t budged I said “screw it” And strided out about 150 meters which seems to have somehow jolted it back to a normal 185. I again checked manually and it was spot on as far as I could tell.

I should say that I am a very experienced athlete with 20 years of experience with these types of workouts… so, I know what feels normal. I felt normal, but decided to terminate the workout with 2 reps remaining based on the high HR.

Has anyone ever experienced anything like this? Should I be as concerned as I am? Thanks for any advice!

Several questions.

  1. What HRM do you normally use?
  2. Do you always use the same HRM for the same kind or wo?
  3. Whats your cadence?

234 is indeed very high. BUT, i have my suspicions of what could it be.

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I use a Garmin Tri HRM and it’s always been extremely consistent over the last several years. Cadence during an interval is around 170 (remember, I’m running not cycling). Oddly, during the interval it was where expected and spiked during the rest period. The blue line is my pace… red is HR.

My initial guess was the case where the pace matched the HR and OHRM goes bananas and start tracking pace. I dont think this happens on chest straps and probably not in your case,
Ive seen my HR go to 210 but i know its that thing (on 5k races i can get to 200 beats on the last 400m and my pace is usually above 200 at 5k pace)

that huge spike really looks like a glitch of data. the way it went up vertically suggest other things going on. How long ago did you change batteries?

I should add, it’s a chest strap HRM

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Funny you asked that… this is only the second workout since a battery change. The first post battery change workout was a long run… 13 miles at an average 150 bpm, no unusual spikes!

I am 28 and experience something very similar to this on a fairly regular basis (1-2 times a fortnight), where I have a run of palpitations (few extra heart beats) that sometimes sustains for a bit and gives me a short burst for about 30 secs - 2 mins where my heart rate is approx 235bpm. I notice the difference straight away and it makes me a bit breathless, so i have to stop or slow down and I have a few techniques to make it stop. Both my chest straps and arm band HRM have been able to pick it up during rides (i will see if i can find some to post)

For me, it is caused by a cardiac arrhythmia that is very common and the most common cause of palpitations in young people. It is pretty harmless in itself to happen and is not life-threatening or serious in anyway, it can simply make you feel dizzy or breathless. I work in a cardiology department in a hospital and was luckily enough to catch it whilst it was happening at work, and then got reviewed by a specialist.

I am not a doctor, nor am i going to diagnose you over a forum, but as someone that does work in a cardiology department, I would very much advise you to follow it up with a doctor if it is concerning you or happening on a regular basis. The key is generally how often is it happening and how does it make you feel?


That’s not really high. I’m nearly 45yo and 200bpm is my absolute max and 180-185 is tempo for me. 196bpm is the highest I’ve hit this year though. My mate who is marginally older (just over 45y) regularly hits 200bpm on weekly a Saturday ride.

If you felt perfectly fine, and has not happen before. I would chalked it up to a device glitch. Maybe its starting to go bad?

If it becomes a thing, i would go to the doctor as @dtidy1609 suggest.

Ive been on the very edge of my max HR (202 running, sprinting super hard up a hill) and let me tell you, you will feel it. Hands and finger get tingling, and you start to feel slightly light headed. It not a great feeling. Ive only managed to do that maybe 2x. Would not recommend.


Thanks! I honestly felt great (or at least how you should feel during VO2 intervals) during and feel great after! I get regular EKGs because I’m an air traffic controller, but obviously I’m always very well rested for them. I’ll check in with a Dr out of an abundance of caution, but I really don’t want to stop working out.


Maybe read further in… I was in the 230s for about a minute

Do you have a necklace, zipper, or any metal near your chest? On an older Garmin HRM I’ve had a flapping cycling jersey cause my HR to read as 210+ on descents where I know my HR was actually under 150.

here is an example of what happens to me every now and again: https://www.trainerroad.com/app/career/dtidy1609/rides/50868397-bashful-2

When it happens to me it instantly goes up to 235bpmish and stays there for a few minutes. A PR for me of average 228bpm for a 90 second interval


100% agree. I’m very experienced and I know what peak HR feels like and this was not it! The few times I’ve been there it is painful! :joy:

You’re probably right and my HRM was glitching out. I’m going to chalk it up to that for now… especially since it dove back down the money cranked up the intensity again.

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Sorry my fingers are crap post chemotherapy, I press return to early all the time. What I was going to say is 234bpm is a spike. My watch reads lot but last week it read 259bpm. I felt fine if you felt fine definitely write it off as a spike, watches are cr@p for hr :+1:

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The fact you feel great (or as great as can be during those intervals) is a very reassuring sign. Its great to hear you have access to cardiac services and have regular assessments. If it is similar to what I have then your EKG will be entirely normal. The fact that your EKG is normal is reassuring and helps rule out more sinister problems. They may want you to wear a mobile or ‘ambulatory’ EKG to try and see if they can catch anything else happening.

+1 I have the same thing happen to me, at roughly the same frequency. Went to my doctor and did a test where I had a Holter monitor taped to me for 3 days, which showed nothing of medical concern. I’ve learned to feel when it is happening (it is a feeling of being a little bit breathless), so when I get that feeling I look at my HRM to confirm and stop activity until my heart rate returns to normal, then slowly ramp my effort back up.

I’ve noticed a weak correlation between these incidents and my caffeine intake, so if I’m exercising I don’t binge on coffee like I used to when I was in my 20s. I’m 52, BTW.


I was fairly heavily caffeinated at the time… I too still like to think I’m younger than I am! The fact that it lasted for as long as it did (about a minute) and I verified it manually makes me think it’s legitimate. I suppose I’ll just keep an eye on it for now and just stop a workout until it returns to normal before finishing the workout. I’m not too concerned because i felt no abnormal discomfort, just the normal pain that is VO2 intervals!

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