Q+A: Why did my heart rate shoot up 40 beats?

Our experts answer real-life questions

Posted: 9 September 2002
by Gregory Whyte

Q During a recent race, while I was running very comfortably, my heart rate suddenly shot up to nearly 40 beats above my usual level and remained there for the rest of the run. At no time did I feel ill or even out of breath, but understandably I was worried. I’ve since seen my GP and am waiting to see a cardiologist, but can you offer an explanation?

A Assuming that your heart rate monitor was not temporarily malfunctioning, and while it’s difficult to comment upon an individual case, I will try to offer an explanation of the commonest cause of unusual heart-rate fluctuations experienced by athletes. Heart palpitations are common in athletes and are usually felt as a regular pounding or racing of the heart in the chest, throat, and/or neck. Some athletes describe it as the heart stopping and then restarting, or a rapid fluttering. Many of the causes are innocent but some do require further specialist investigations.

The heart normally beats in a regular (sinus) rhythm with the upper chambers (atrium) contracting first, followed by the lower chambers (ventricles). The contraction of the heart is facilitated by an intricate ‘wiring’ system that can be examined using an electrocardiogram. Palpitations usually result from a premature contraction of the heart muscle, which causes the symptoms mentioned above. These premature contractions are normally short-lived and the heart quickly returns to its normal rhythm.

The low resting heart rate of many runners may be one of the causes of palpitations. Others include stress, caffeine, alcohol and certain drugs (including some cold cures). Many athletes will experience palpitations, which usually only last a couple of seconds, during their athletic career. Indeed, everyone will experience palpitations at some time in their lives, and the palpitations brought on by strenuous exercise or high emotions are rarely associated with underlying cardiovascular disease.

However if palpitations are a frequent occurrence or continue for many minutes, and/or there are other associated symptoms (such as unusual shortness of breath and sweating, dizziness or fainting) you should consult your doctor. This is especially important if you have a family history of heart disease.

Dr Gregory Whyte, research manager, British Olympic Medical Centre, Northwick Park Hospital, Harrow

Previous article
The Seeds of Speed
Next article
Half A Century Of Advice

heart rate, palpitations

Discuss this article

I have just read the question about a sudden rise in heart rate sent by Gregory Whyte. I experience similar symptoms.

In particular I note an initial decline in heart rate when stopping exercise, then often a sudden rise from say 100 to 140bps. My pulse then recovers to normal but with a sudden drop. I can get raised peaks during exercise too.

I feel no physical ill effects.

I've discussed these symptoms with a cardiologist from Harefield. He cannot explain them, and says I should continue to exercise as normal unless I feel unwell.
Posted: 21/11/2002 at 21:24

Probably a bit of a silly question, but where do you do your training, if you train on a tread mill there may me cross talk from other belts, monitors or even some machines can cause errors on the monitor.
I've seen monitors jump from 110 bpm to 150 with in seconds.
You probabley know this anyway.
Posted: 21/11/2002 at 23:15

Good point about tread mills - I've certainly observed some odd things happening sometimes. However the effect I was referring to occurs when running outside the gym. Also it usually, though not always, occurs within a few seconds of stopping after running.

I kept a diary of activity & unusual pulse rate events which I reviewed with a cardiologist. I have regular check-ups since I had a coronory angioplasty some years ago. He does not seem to be very concerned as long as I feel OK.
Posted: 22/11/2002 at 22:43

I have experienced this on a regular basis during my long slow distance runs. Last Friday I went out planning on a 20k LSD run as part of my marathon training. For about 1hr 40mins I managed to keep my HR to around 132bpm and really easy running. Then suddenly I was reading 155 without increasing the effort. In fact I was deliberately trying to slow down and suffering from shortness of breath. Howevr, as soon as I stopped running my HR came down. This period coincided with my legs starting to feel stiff and heavy.

Could it have something to do with my body's ability to stay cool? I do all my training in the middle east it was cool and windy when I went outon Friday then it got to around 25 degrees C.
I make the effort of staying hydrated and did not feel thirsty no dryness in the mouth and even had some water left at the end. There was no lasting affect other than feeling a bit knackered for a while.
Posted: 18/02/2003 at 07:49

Interested to see someone else with these effects. I'm still running! Of the two types of symptom that I observe - one is very similar to that expressed by "COL". If I've been running steadily for some time and then ease off I see a pulse rate jump typically from 130 to 150 bps. This happens too when I stop after a run, and it can take 5mins for my rate to settle back to normal via a series of peaks and troughs.

More rarely - I can get a brief peak while actually running at a constant rate. This lasts for a minute or so, then my pulse comes back to where it was.

I suspect that these could be something to do with overheating or lack of oxygen - but I feel fine and do not experience any symptoms.

I'd be interested to hear from anyone else with these symptoms.
Posted: 18/02/2003 at 13:57

Not noticed it myself - maybe there's some primeval effect in that man as a hunter would need the extra blood flow once he had stopped running across the plains in order to fight back against predators.

nope... I'm talking b*ll*cks again.

I'll get my coat...
Posted: 18/02/2003 at 17:24

not sure if this is what you're all talkin about but -

it's an established fact of interval training in particular that your heart rate rises immediately after the repetition and during the first moments of recovery, and this is where the "training effect" is actually taking place.

any use to anyone?
Posted: 18/02/2003 at 17:51

Is this a gradual thing though ? I've used HRMs for years and years now, and I've never known my hr to jump 20 beats without extra effort.

As Achilles says - if you do an interval, the hr lags behind slightly so that even when the interval is over your hr does climb to a peak, but this is only for a few seconds (5 at max ?)

EP is right about heart creep too - as your body gets more fatigued it will need a higher HR for the same effort.
Posted: 18/02/2003 at 20:53

I have no personal experience of your symptons Michael. But I was talking to a triathelete friend of mine, he is a veteran (now 60yrs) who has qualified for the worlds the last couple of times. He had reason to see a sports cardiologist and mentioned to him about the rise in his pulse sometimes, similar to your experience. It was suggested that it was dehydration that can cause this. Derek on his next race noticed that his heart rate had jumped a little and at the next water station (of his run) took on water and a gel and within a few seconds it had settled down again. I thought it worth a mention in case it has anything to do with your 'problem', and you can now try and see if taking on water/sports drink can help resolve.
Posted: 24/06/2003 at 08:12

I have just noticed the date on your postings, you have probably resolved your probalem now anyway!!!
Posted: 24/06/2003 at 08:14

Kind of related ....I have tried a HRM for the first time today, and as its a novelty I am wearing it all day. What is shocking me is that my resting rate is 58, normal sitting is about 70, but just by thinking, standing up, etc it jumps around between 70 to 100. The only time I got a consistent reading was when running..it was 173(doing fartlek).
I wonder if it has something to do with low blodd pessure?
Posted: 06/07/2003 at 16:28

had this happen too, but i'm almost certain its the watch. since: i) it goes to max (~231) ii) only happened since the battery was replaced -the beeper was also a casualty of this somewhat amateur repair.

Posted: 22/04/2004 at 13:41

Sheesh! Just got a notification for this.

Did you spot the date on it susho?!!!

I still think my primeval hunter gatherer observation was rather good...
Posted: 22/04/2004 at 13:52

didn't spot the date...but an article worth reading. i guess rw are milking it. i arrived here from a link on the homepage!

Posted: 22/04/2004 at 21:37

The recent letter about erratic pulse measurements (RW, May 04) seems related to this thread, and certainly struck a chord with me.
I too have often noticed erratic readings, and had put it down to interference from pylons, railway lines, electric gates etc.
Except that it was happening at other times too - on the beach, in the woods - when there was no obvious source of interference.
Then I started noticing my pulse speeding up when I wasn't exercising.
I strapped my monitor on, and my pulse would be way over 100, when I wasn't doing anything, and would expect it to be 50-60. My pulse would be erratic, shooting up, and dropping down, but generally higher than normal.
These 'episodes' would occur fairly infrequently (every few months or so), for no apparent reason, and would last a few minutes, or a couple of hours, then subside, leaving my pulse to gradually return to normal.
Recently, they have been getting more frequent (2 or 3 times a week), and
lasting for longer (up to 15 to 18 hours), including overnight.
There is no pattern: I have stopped coffee; they occur at any time of day, though often late evening; regardless of exercise, alcohol, or food.
In short, there is no discernable pattern.
My GP referred me for a 24-hour ECG which was inconclusive, but the consultant has said it is probably 'paroximal (?) atrial fibrillation', which in itself is harmless, but I need to undergo more tests to see if there is an underlying reason which causes the condition, and could explain the increasing frequency.
I am a 48-year old male, 5'10", weighing 11st, running regularly for 20 years.
I don't smoke, and drink in moderation. My normal resting pulse is about 44.

Is this condition common amongst runners? Is there a common underlying reason?
Are there any things to do, or to avoid, to stop it becoming even more frequent?

Posted: 28/04/2004 at 10:57

No idea, misterP. I might try this thing of wearing the HRM all day and see what happens.

No predators prowling around at the time then ;-) ...
Posted: 28/04/2004 at 11:15

I have been training for 14 weeks for a marathon and today I didn't hydrate myself enough. I ran 6 miles at race pace and then 1/2 mile at a slower jog and then walked for about 2 minutes on the treadmill. My heartrate dropped normally to about 100 before I stopped. I then walked down a flight of stairs to a locker and when I arrived my chest was thumping at the sternum about 150 BPM it lasted for about 5 minutes. The strange thing was that I took my pulse while this was happeneing and it was about 74. I didn't have any symptoms like pain of shortness of breath, it was just thumpin fast and real weird, little scary actually. From reading this thread it seems the most likely reason is the dehydrating. For myself that is the only thing that was different for me with all the rest of my training. I'm thinking of just keeping track of this for now and continuing the training.
Posted: 16/09/2004 at 01:59

I have an identical problem to the initial posting. The problem has been there for years but I have only recently identified it. Interesting to see that it is fairly commonplace.
Like the first poster, my HR will make a sudden jump of maybe 40 to 60 bpm, always triggered by exercise. The high palpitating HR is uncomfortably vigorous. When it happens I stop and a within a minute it will make a sudden drop back to normal. I can then continue to increase the exercise pace as though the palpitation had never happened. Sometimes it happens several times, usually in the first ten minutes or during winding down, only occasionally during the body of the exercise period. Sometimes I can prevent the palpitation by feeling that it is coming (a building of a jittery fluttering feeling in the chest and upper stomach) and easing back very slowly.
The thump of the feet appear to cause the palpitation to be more frequent during running than other exercise. Jumping is most likely to bring on the palpitation.
As I said, I stop and rest when the palpitation commences. I find this better because whilst I can continue, my power output is much reduced for a given heart rate when the HR is flipped into the over-speeding state.
Can anyone help work out the association between trigger and effect because the occurrence is very variable and there may be some easy links like food, sleep, alcohol etc. ?

Posted: 08/11/2004 at 19:47

I also experience a jump of 30 to 60 bpm occasionally (probably not more than 5 times a year), always triggered by intense exercise, usually when pushing myself unusually hard (e.g. a race) after a period of slightly reduced training.

I can always feel it about to happen a few seconds before it does. If I stop exercising immediately it always returns to normal within about 10 to 20 seconds.

Yesterday it happened twice during the Flora London Marathon - once around halfway, and more critically in the final 800 metres! I happened to be wearing my shiny new Suunto t6 watch which captured the palpitations and its dramatic effect on my speed for all to see:


(If the graph had higher resolution than every 10 seconds you would see it actually peaked at 238bpm.)

On this occasion I think it occurred because my final 2 months of training were badly reduced due to a minor injury (which ironically didn't pose a problem at all on the day), so attempting to run the whole 26 miles at 177 to 180bpm on less than peak form was probably asking for trouble!

I think it would have happened on several other occasions throughout the race had I not slightly eased off the pace when I thought it was about to reoccur.

Unfortunately I lost about 3 minutes in the final stretch, which put me 20 seconds outside my PB. Oh well!

Should I see a doctor for a check up?
Posted: 18/04/2005 at 16:01

Adam, Your graphs are a bit fuzzy but the general characteristic, sudden rise, sudden fall to a HR below what it should be, followed by recovery to normal HR is similar to mine which has been described as 'paroxysmal atrial tachycardia' or intermittent fast heart rate initiating from a rogue atrial focus.
Unfortunately, doctors and cardiologists are NO help at all on this.
Nevertheless, there must be a way to beat the imbalance or whatever which causes the rogue cells to fire prematurely, after all the problem doesn't happen all the time.
But I have no fix to offer, I'm still searching for that link.
Posted: 19/04/2005 at 00:52

I have a friend who is a top drawer veteran tri-athelete, he also suffers similarly, but maybe more so and he saw a cardiologist who deals with sports people, (Crystal Palace recommended), he has been given medication to deal with the problem. One thing that he has noticed in races in the past is that it will happen more if he was dehydrated and a drink of water used to fix it.

Posted: 19/04/2005 at 08:17

ceal, what was the name of the medication?
Posted: 19/04/2005 at 09:35

Linsay I don't know, but I will find out for you right now by e-mailing the person involved.
Posted: 19/04/2005 at 09:41

Lindsay, I have cut and pasted my reply from my friend Derek. I hope it helps.

With regard to your friend I would suggest she tries to get in touch with a cardiologist specialising in sports related problems.These usually based at big hospitals, possibly Guildford, St Georges Tooting & I think now, Mayday. However she could try the British Olympic Test Centre @ Harrow Hospital where I was sorted. Talk to Greg Whyte 020 8640609. Be aware their policy has changed due to funding & he may not be able to help.
Normally they would put her on exercise test to determine the problem or possibly do an angiogram, the camera in the groin job to check the arteries.
If she uses HR monitor it may be worth keeping record of when instances occur, weather conditions, type of training, does food affect it, what no HR goes to etc.
There are obviously loads of causes for this problem, mine is electrical.
Just as an aside my tablets are FLECAINIDE ACETATE.
If she wants to have a chat get her to give me a call.

I can let you have his telephone number if you want to have a chat with him, his name is Derek. He has put the Guildford contact because I live in Guildord and he is presuming that you do too!
Posted: 20/04/2005 at 08:41

I have just seen the recent postings in resoponse to my original note (some 3 years old now). It's comforting to see that some others do have the same symptoms. Let me update you on my recent experience.

I continue to run regularly, 20miles+ a week. I continue to experience the same symptoms - that is periods of raised pulse rate during recovery after runs (a jump from 90 to 140 being typical, with a decay & then a drop to 70). Like others have mentioned I can almost anticipate them happening. Occasionally, though rarely they occur while running.

I had an exercise ECG test, & the effect was seen . My consultant described it as "a curious tachycardia" after exercise, during the recovery period. He had no explanation for it, and doesn't seem very bothered by it.

So I suspect what we're experiencing is some effect caused by overheating, shortage of oxygen or dehydration.

The guidance I've been given is not to worry about it unless I faint or feel faint.

Posted: 20/04/2005 at 22:16


I don't think mine ever occurs during the recovery period - it's pretty much always when I'm pushing my heart significantly over what it's used to. Same tachycardia but different triggers I guess.

I suspect the doctor's advice would be "so don't do that". Prior to FLM2005 it last happened around 8 months ago during my first ever 5k race, which again was a situation I pushed myself way past what I'm used to. Maybe more regular racing or race-like training is called for, so that on the big day my heart doesn't get such a shock.
Posted: 23/04/2005 at 14:08

Following my post of 12 months ago, an update: after further tests, including echo-cardiogram and several 24-hour ECG's (which never co-incided with an 'epidode') I was put on beta-blockers, to slow my heart down, but these were useless, as all they did was just that - slowed it down. This meant my resting HR came down from a healthy 44 to below 35, and I my max dropped to around 140 - it meant even an easy run felt hard work. Also, they did little to stop the fibrillations occurring - they were just a bit slower.
Eventually, I was put on Flecainide Acetate, and these seem to have done the trick - my heart is more regular, but within the normal range, meaning I can run, do intervals and even race. I still get the occasional 'attack' (my consultant called it 'paroxyssmal atrial fibrillation' - I guess that's the same as tachycardia), but not quite so often, and definitely not as severe, or long-lasting.
They still occur predominantly in the evening, often just on going to bed, so maybe low hydration has something to do with it, but I've also noticed another trigger which if it wasn't so consistent, I'd dismiss as bizarre :- if I do anything which involves bending and twisting, this can trigger it. Bending to lift a heavy weight can do it, but even bending to get something out of a low cupboard, or twisting sideways can cause it.
My theory: pressure near the kidneys, where the adrenal gland is situated, causes a fluctuation in adrenalin, triggering a fluctuation in the heart-rate. Doesn't explain why it doesn't come straight back to normal, but I did say it was bizarre
Posted: 24/04/2005 at 21:57

Sympathies to all and "Snap". Glad I'm not the only one that the quack looks at you like you are a retard. Although in my case.........

Soon as I see 175 at 12 minute miling, it's hit the brakes, suddenly, all stop, and restart again, seems OK.

Now all I have to do is to get it to beat at the same intervals.

Good luck all.
Posted: 24/04/2005 at 22:10

The post by ‘MisterP’ set me thinking as to what exactly is the trigger for the tachycardia run.
Yes, stooping quickly to pick something off the floor is a clearly identifiable trigger So are the running equivalents clearing a style at speed or running over small hump, and running downhill.
There appear to be two criteria for a tachycardia run to be initiated. First the heart has to be primed to misbehave which seems to happen mostly when the heart rate is increasing or decreasing. That bit is still something of a mystery. However the actual trigger requires a sudden twist or bending over. Without sudden motion of the chest, the tachycardia does not trigger.
I put this to the test by getting my rusty bike out and cycling my standard road running route. As expected I found I was able to ramp up to 75% to 85% max HR and hold it for 30 minutes without interruption from tachycardia. Running the same route for 30 minutes even at a lower HR typically causes 4 to 6 or more interruptions due to tachycardia.
The deduction is that if the upper body remains still, then the tachycardia does not trigger. Running jogs the chest, cycling mostly holds it still. Walking is something in between.
One immediate very valuable benefit is that I now have a way of reliably exercising in the HR target zone without interruption.
Since the trigger has immediate effect, this points to the rogue cells which are responsible for the tachycardia being sensitive to compression, stretching, twisting or shock. Is this a new lead for the cardiologists?

Posted: 04/05/2005 at 14:53

A useful book which makes sense of an ECG and the heart’s electrical problems is ‘ECG Interpretation’ published by Lippincott Williams and Wilkins 3rd edition 2005 ISBN 1582553556. I bought a few books but this one was the best.
Posted: 04/05/2005 at 14:54

On the subject of the drugs available, Flecainide Acetate included (thank you, 'Ceal'), the curious thing is that side-effects include the very problems the drugs are prescribed for, palpitations, arrhythmias, even heart failure. GPs and cardiologists seem to like them. There is a surprisingly large number of them. One of our GPs in Castle Donington suggested I choose one at random and try it. Perhaps they work by making the heart so wrong it might just become right. The drugs don’t address the root cause of the problem, they merely slug the heart which means they can never be satisfactory for active people, and worse, there is the addictive effect, in that there are serious withdrawal symptoms and risks. Once you start taking one of these powerful drugs, the heart adjusts to it, and you can not easily go back. Catheter Ablation can be a complete fix because it burns out the rogue cells but does have serious risks like damaging or burning out the wrong bits (equals pacemaker required or sudden death).
All that said, it is encouraging to hear of two semi-success stories with Flecainide Acetate but I won’t be trying it just yet, still too scared of a repetition of my experience last year.
A cardiologist persuaded me to try bisoprolol, a beta blocker (brand name Cardicor) with the specific promise of carefree running again. Reluctantly I agreed a month’s trial. After 7 days the tachycardia bursts had become slow and damped but more frequent and same intensity and the chest felt filled with cement so there was clearly no fix happening. More serious, there were new symptoms, dizziness and nausea during tachycardia episodes. Also I began feeling generally unwell and disconnected from the world. For all these reasons, I stopped with just 7 tablets taken. That’s when the drug really hit me. Withdrawal lasted three months. The chest felt bruised and tender, the solar plexus constantly jittery. The first few weeks I experienced extreme exercise intolerance, like having to shower sitting down, take rests while brushing teeth, walk at a snail’s pace, otherwise the heart would race (in normal sinus mode).

Posted: 04/05/2005 at 15:02

Jeez, this sounds horrible. Breathless too?
Posted: 04/05/2005 at 15:17

Lindsay, sorry to hear about your bad experiences with BB's. I took Sotalol for about 3 months, with the effects described previously. Initially 2 per day, but that slowed me right down. Reducing to 1 per day meant it had no effect, so compromised at 1.5 per day. Pulse reduced, fibrillations reduced, but everything else reduced as well! Not quite depression, but getting that way. Been on Flecainide for 9 months with no problems so far. Had come to terms with long-term (i.e. permanent) nature of medication, but hadn't realised the 'addictive' effect. Will speak to GP at next review.
Looks like everyone's condition and/or trigger is slightly different. In my case bending/twisting (thanks for confirmation by the way - I thought I was imagining it) is just one of several causes. Exercise does NOT seem to be a trigger, as episodes occur independently. I sometimes get them just after exercise, very occasionally during (once during a race), but usually not connected.
Over a 10 week period last summer, I had 25 episodes at different times of day (mostly late evening) varying in duration from 30 mins to 30 hours, with average 12 hours. Only common thread was after effects: faintness on getting up, and extreme fatigue as though I'd been doing strenuous exercise for the duration. Needless to say, if they occurred during a race, or the night before a race, my performance suffered.
As my condition is 'paroxyssmal' (i.e. intermittent), and rights itself eventually, ablation was not an option. Apart from which, I'm not THAT P.M. !!!
Regards, PM
Posted: 06/05/2005 at 09:27

Just an update from me as the originator of this thread. Thanks for all the interest.

I continue to run with no ill effects. I was recommended to try a beta blocker some time ago, but it just slowed me right down and took me a while to wean myself off it.

I had a period when they would occur an hour or so after a hard swimming session. That happens less frequently now, but I have had crawl lessons to improve technique and have become fitter so maybe there's some indication of hydration or oxygen depletion being a factor.

In the last year the events seem to have been less frequent during running too. I have been careful to hydrate properly and have been taking a suppliment of Co-enzyme Q10, available from health shops, which is said to help regulate heart rhythms.

The medical profession havn't really come up with a satisfactory explanation. The events have been captured on a 24hr ECG tape so they are real! My consultant was interested in my Co-enzyme Q10 observation, maybe there's something in it. Overall the advice is to continue as normal unless I experience dizziness or blackouts.

I'll mention some of the points in the thread next time I see the cardiolist.

Posted: 06/11/2005 at 15:21

We'd love you to add a comment! Please login or take half a minute to register as a free member

Smart Coach
Free, fully-personalized training plans, designed to suit your racing goals and your lifestyle.