Heart rate spikes at the start of the run leg

Can’t say that I’ve noticed this in previous years maybe because I don’t do much short course, but what can I do to smooth these out for my next race?

I started my watch after about a few minutes of running, and you can see it’s climbed to my maxHR 190, even slightly above anything I’ve seen in the last few years at 195. Then it did it again three minutes or so later, and again around ten minutes. But as you can see my pace isn’t going up and the route was flat at those points.

I had something similar but not as high at the start of my (edit) Dartford olympic race in June but then I felt bad as well, and eased off:

What HRM are you using? And how come you’re only starting your watch after a few minutes of running?

I missed seeing the timing mat
Garmin Fenix 6 S pro

Wrist or chest?

Wrist and is as consistent as an HRM dual. You can see these aren’t aberrations - or rather, I am confident they aren’t.

I disagree. If those spikes are based on wrist OHR, then that is almost certainly the cause in my opinion

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Wrist heart rate sensors take a few minutes to lock onto your actual heart rate from within the noise of all the movement. They often lock on to cadence instead, after a few minutes they correct themselves.

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It’s not the device, I’m sure.

These are four runs I did this week after the triathlon:

Also, the Dartford olympic was recorded with hrm dual - EDIT: not true

Also, I compared watches and the dual hrm over a course of weeks when I got them and found nothing more than a 1-3bpm variance

Also, the run split is not a new session it’s part of a continuous triathlon record, the device has been recording for an 90mins already and the run split graph lines up with the T2 graph

That’s a fair point @joex but, to my mind, I agree with @stenard. It doesn’t seem physiologically likely.

Unless you left t2 like an absolute bat out of hell, I can’t see why your HR would spike to a higher than ever seen value.

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But that actually makes it more likely to be wrong, as the conditions it’s learnt and locked in on have just changed completely, and a time of rapid changes in heart rate (slowing on the bike getting ready to get off, “resting” but stressful transition, then straight back to running) along with hand position changing and moving throughout it.

That’s different to a new activity, The 25 beats increase at 9 minutes looks exactly like a wrist HR failure mode.

Wrist HR is the least reliable method of recording it. I’m always moaning about it. If I look down and see that my HR is 165 and I’m jogging, it doesn’t surprise or concern me!

Secondly, like Jim says, it’s to be as expected to get elevated HR as you transition; it’s a combination of poor sensor reliability and moving to a more demanding activity, the run.

I get the strength of opinion on wrist based OHR, and I’m considering it. It does not seem to gel with the fact that my HR goes up to 190 after ten minutes of running though, nor does it bear relevance to the race with a chest strap.

Are there any physiological reasons as @gingerbongo puts it, this could happen? It’s not like I have Tim O’Donnell on my mind or anything :wink: :fearful:

Basically I was going to start practicing brick sessions more and looking at the HR stats, and see if I can find something that leads to less stress and a more stable HR with longer distances and lower paces.

Lots of people seem to have a history of problems with wrist based OHR, but I’m not one of them.

If you felt your heart pounding out your chest like you were max effort and then eased off and stopped trying then yes maybe it’s true.

If you were even remotely even paced effort and working hard towards the finish then no it’s not physiologically going to be a sudden HR spike that doesn’t correspond to effort, barring a pathological arrhythmia (less likely than a HR malfunction, and still likely to be associated with symptoms)

Sorry not to give you the answer you want but agree with everyone else, and last time you asked similar Q about non-corresponding HR from watch (IIRC, might be wrong/having deja-vu!)

For what it’s worth I’m not just attacking wrist HR, even if it was purely chest strap I’d still say sensor misreading is more common that heart malfunctioning.

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So the first time this was recorded, in the Dartford Olympic, I felt bad and was getting a stitch under the rib cage - the first time I’d experienced that - easing off just a fraction of the pace and bearing through it I felt better and completed the run as expected.

In the London Olympic I didn’t feel bad but I did sense the potential of a stitch coming on, so I was more surprised to see the high heart rate peak, and to peak twice. I was running marginally faster than planned though, I suppose.

When I set my 5k PB in January and my HR rose steadily to 190 I had to take a walking break but I did not feel my heart was pounding in my chest or ears or anything, I just felt that I couldn’t keep the effort up.

I had tests done a few years ago when high blood pressure and cholesterol was detected, I was put on a minimal dose of statins for a 3 months then taken off. They tested my heart for arrhythmias I think, and said I shouldn’t do any maximal efforts for a while.

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I get why people might think this, but I want my opinions to match my evidence, that’s all - I have no preferred answer.

Oh and for further clarity, I don’t display my HR when running so that there is no chance of my RPE being influenced by what numbers I might see.

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Couple of points.

In a standalone run, you’ll have probably located your watch nice and snug, and the OHR sensor is starting from clean, non-sweaty/wet skin.

In a tri, your watch will have been bounced all over the place on the bike, so maybe a bit loose, and your skin will be damp and wet. And as Jim says, if you are recording a multisport activity, then the OHR is having to try and switch from recently recording a bike session, to a run session.

It’s a widely known fact that wrist based OHR is absolutely atrocious on the bike (outdoors - less so indoors), as the vibrations from the road and the restriction in blood flow caused by gripping the bars, plays havoc. Every single respected reviewer reports this. So it is no surprise to me that the OHR sensor takes some time to figure things out as your arms begin to sort themselves out again and normalise.

Yeah sorry, reads bit harsh typing in a break at work.
My take home would be that no tech ology is infallible. I can show you lots of my HR traces near identical to yours, for example:

Both the high HR in my warm up, and then again abnormally high above my max for couple minutes towards the end

With respect this is not nearly identical to mine. Mine report a rise and fall, not a sudden switch down by dozens of bpm. I’m familiar with misreporting devices, and they don’t look like mine, they look like yours and/or have sudden spikes from one minute to the next.

I understand the strength of your opinion and why, but in front of you are two races one with wrist base OHR and one with a chest strap, and they both show broadly speaking the same thing. A rapid rise in heart rate then it drops off, rises again, drops off and eventually settles. To dismiss both because of preconceived ideas on wrist based OHR just isn’t rational. :man_shrugging:t2:

I will do a brick session tomorrow morning, and find a way to record both watch HR and chest based HR if you like to see if there is any significant difference. However there was zero interest in my thread comparing watches and straps previously.

The sudden switch down in warm up on that first image is because I’ve seen it misreading, stopped the watch and s readjusted/wet strap.
This one any more similar? For an easy run I’m sure my HR didn’t cross 140-145.

I’d be fascinated if there was a physiological explanation, rather than just wanting to slate your HRM. But I can’t think of any other reason, so I’m left with technology being by no1 choice.

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If I missed you saying that subsequently, then I apologise. I asked at the outset what HRM you were using and you said the watch/wrist OHR.

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