Strava HR Data has me worried... Doc in the house?

[JimmyTango]

My HR data for today's ride shows several spikes up to 230ish BPM.

I am 30yo, 6'2" 170lbs, and have been very fit my whole adult life. My calculated "max" is 189, but it isn't uncommon for me to push it up to mid 190s in races.

This is the first time I have seen it spike like this (above 195, not correlating with max effort). I didn't have any more or less coffee than usual this morning.

Most of the spikes happened during the first half of the 3 hour ride. I was definitely in "chill mode" until the 2nd hour or so and the spikes don't correlate with increased effort (several are on descents actually). Once I actually started pushing it out of z2 or z3, the spikes stop and my HR looks like it usually does.

I would write it off as a Garmin error, but I ended the ride feeling uncharacteristically "bonky" and have been concerned by a pretty precipitous drop in fitness in the last few weeks despite a fairly standard training schedule.

Am I going to drop dead next time I go out and ride?

[soulspinner]

Its probably arrythmia but by all means go see a doc.

[benb]

You sure the HRM is actually accurate?

I have a real problem this year of my rides looking like they start out with me riding at max HR for the first 10-15 minutes w/spikes to 230.. it's not arrhythmia it's the HRM not working properly due to weather and me needing to work up a sweat before it starts working.

If you think it's anything real and you felt like you bonked maybe ask yourself how much caffeine you'd consumed that day, etc..

I actually think there is some error and/or weirdness in Garmins that causes them to report 230bpm in error conditions. I should ride with 2 cyclecomputers but my Bontrager computer NEVER reported 230bpm when things were wonky, it would report low. (Same strap used with both devices) Unfortunately the Bontrager doesn't record so no way to really test this. But I've watched the garmin show 200+ bpm when I'm in recovery/warmup mode and I can take my pulse and know the garmin absolutely doesn't pass a sanity check.

[kgreene10]

My HR strap paired with Garmin 500 shows incorrect spikes all the time. Yesterday, I rode easy for 90 mins and my HR probably never went above 145 but the data showed a max of 179 once uploaded to TP.

If you want tons of errors, try an optical HR monitor.

[phutterman]

That sounds implausibly high to me, too. I still suspect that's HRM jitter. I've seen mine do that a handful of times, too. I'm pretty sure you'd know if it was actually that high. I think you'd feel your heart racing.

Interesting point if 230 specifically is what the Garmin records in error conditions. I'll see if I can track down an example of mine spiking and see what it read.

I've been slow and bonky when it's as (comparatively) cold as it has been, too. Your body's working harder to keep you warm and stuff.

I'd say try and keep a closer eye on it when you're riding - see if you see it spike and compare that to how you're actually feeling. And if it keeps doing it you can borrow mine or something for a few days. It's...moderately clean.

[JimmyTango]

Originally Posted by phutterman

That sounds implausibly high to me, too. I still suspect that's HRM jitter. I've seen mine do that a handful of times, too. I'm pretty sure you'd know if it was actually that high. I think you'd feel your heart racing.

Interesting point if 230 specifically is what the Garmin records in error conditions. I'll see if I can track down an example of mine spiking and see what it read.

I've been slow and bonky when it's as (comparatively) cold as it has been, too. Your body's working harder to keep you warm and stuff.

I'd say try and keep a closer eye on it when you're riding - see if you see it spike and compare that to how you're actually feeling. And if it keeps doing it you can borrow mine or something for a few days. It's...moderately clean.

Yeah, I'm kinda hoping/ leaning towards the garmin error angle.... each aspect of today's ride could easily be explained away by other factors (e.g. bonking because the only food I had eaten since dinner last night was a 150cal bar when I woke up), but it is a pretty scary reading to see, especially because I've been riding with the same strap and garmin for a year and this is the first time this has happened. Plus, I have been riding like ···· for a few weeks now and can't really figure why so I'm being neurotic about little things. Mainly just checking that no one chimes in with "this is EXACTLY what happens to me and I have discovered that it means bla bla bla that you should be worried about!"

Reckon I'll just see if it persists and worry more then.

[notsew]

My buddy had some serious spiking happen while he was riding (it was arrythmia). And he could really feel it. Like stop the bike feel it. So that's a date point for you.

[benb]

This is super easy to see in Garmin Connect, go to your Activities page, filter for cycling, then sort by Max HR.

Here is the first page of mine, I only have 6 months of data in my Garmin account. I don't believe for a minute that any of these with the possible exception of the 194s are legit. Note they're all once the weather starts to get cold... dry weather in the 50s temp wise will make my HRM do this very easily. I go into the 180s if I really, really push it (I think my threshold is around 170) but legit 190s is very rare. I guess this defeats my idea of seeing 230 as a magic # on garmins but it has been very noticeable that the garmin errors high when previous devices I've had error low in the same situations where the strap starts getting hard. If I drill into the individual activities I can see it's always at the beginning of the ride and it's an extended impossible period above whatever my real max HR is.

The only thing that really bugs me about this is I kind of like the Strava Stress scores since I don't have a power monitor. And this wonky HRM data from the garmin really throws a wrench in Strava stress scores and the fitness and freshness graph when you're doing shorter rides. I do a lot of rides that are 1 hour.. if the HRM reads outrageously high the first 10-15 minutes it puts a pretty substantial error into the stress score for that ride. It causes the stress scores to error high though, and that's fine, because left to my own devices I overtrain, if I take the stress scores at face value it's a good thing.

[benb]

Here's a graph of the first 20 minutes of a ride with a max HR of 245.. really bad behavior the first 20 minutes. Note for a while no HR data at all at first then super high readings. I think the no readings is not enough moisture on the skin for a reading and then the super high readings are one side of the sensor picking up and the other one not picking up. (Wind from one side or something.) This ride everything looks perfect from about 20 minutes on.

If you can jiggle the strap around and make the readings go back into a range you expect it's probably not arrhythmia! That often works for me as it gets some moisture onto the electrodes. (I've had an EKG, pretty sure I'm fine)

[eBAUMANN]

that graph looks like crappy data to me, the way it spikes up and drops off suddenly. id blame the HRM.

[Louis]

If the spikes are pegged at the highest the HRM can handle and only happen in specific geographic areas it could be due to EMI. (electromagnetic interference) There's a spot on the road into my subdivision, close to one of those big 3'x3'x3' transformer boxes sitting by the side of the road, (at least that's what I think they are) where my Polar always goes haywire and causes the display to max out. Ride a few yards past the box and the display goes back to normal.

[cnighbor1]

after my heart attack and recovered I took a stress test to see how heart was doing
they measure you at rest than put you on a treat mill and increase speed and incline and keep measuring
that is what you should have has any problems will show up there before out on the road riding

[christian]

You should always lick the electrodes before putting on the strap. If that doesn't work, see a doctor.

[Louis]

Did you try to measure your HR "manually?"

I'd make sure the data's real before worrying too much about it. It's simple enough to stop and see what you measure yourself. If that's close to what the HRM is saying, then yes, seek medical advice, otherwise, you have no clue if this is noise or actual stuff.

[Black Dog]

Well, if you had a 200+ spike during low activity and were not aware of it I would be surprised. An accelerated heart rate is not a symptom that usually goes unnoticed. I would think that you have a instrumentation error and not an underlying pathology at play here. Declining fitness and feeling crappy after a ride sounds more like overtraining. This can lead to cardiac drift but usually not discreet spikes in HR that are not precipitated by increased effort. At the extreme ends of overtraining you can get sustained elevated heart rate. You can confirm your readings with a finger on your carotid artery on your neck during one these events, your pulse at your finger tip will not lie.


You can always go to webMD and find out what type of rare terminal disease you have... Remember that any internet health advice from me or anyone is to be taken with a grain of salt; large grain. None of us, myself included, have enough details to give a reasonable diagnosis. Please rule out instrumentation error and if you can not go see your doc for an EKG and or a cardiac stress test.