Funky heart rate (meter data?) during high intensity intervals

[geordanh]

Hey guys.

So I will start with the obvious: I've got an upcoming appointment with my GP so I'm going to ask him about the below while I'm there just in case there's any real health concern. That box is checked.

That said, I'm wondering if any of you have had similar experiences when looking at your heart rate meter data during high intensity intervals

Here's about a 5 minute snapshot of a recent ride around threshold:

https://flic.kr/p/RvA7o8

Heart rate data looks smooth and fine.

Here's a snapshot (also 5 mins) from the same ride during a vo2 max interval:

https://flic.kr/p/QsFihk

The data is really blocky, and my heart rate seems to jump around with 10-15 beats variance up or down from the average. My power readings are bouncing around a bit (just as they are in the first snapshot at threshold), but at threshold my heart rate doesn't seem nearly as sensitive to slight changes in power as it does at vo2 max.

Here's a more zoomed out view where you can see how weird and blocky the heart rate data is during the interval.

https://flic.kr/p/RGroUF

Do you guys notice the same phenomenon in your heart rate data during high intensity intervals? Wondering if I should consider buying a second heart rate monitor just to compare the data (an accuracy issue at higher bpm with what I have?) and of course the doc may have an idea whether it's something I should be worried about or not. I've looked at a few of my friend's strava data and haven't noticed the same thing so thought I'd see if anyone here has experienced anything similar.

I definitely feel like I'm about to die by the end of one of these intervals but that's pretty normal. :)

[Charles M]

This looks like noise (bad signal process or reception)...

What monitor do you have now?

[Ralph]

Your GP will send you to a cardiologist. Pick one who is a runner or cyclist...or both.

[Tony T]

Well, it would be a good idea to compare to another HR monitor.
Also compare your HR to: http://www.heart.org/HEARTORG/HealthyLiving/PhysicalActivity/FitnessBasics/Target-Heart-Rates_UCM_434341_Article.jsp#.WI_gBBjMzNw
AFAIK, your max HR (during intervals) s/b 220-age.
You should try to keep your HR below the max.


I definitely feel like I'm about to die by the end of one of these intervals but that's pretty normal. :)


You might be just doing the interval too hard, just back the power off a bit.


What App are you using for training?


.

[dem]

What device are you using to measure? Anything other than a chest strap and a dedicated device set to 1 second sampling (not "smart sampling") will be untrustworthy.

I've been using an HRM for 20 years, and my max has not varied by more than 1 or 2 bpm. And there is no harm in a fit person bouncing against their redline - it is self-limiting, you aren't going to hang out at your max for more than a few seconds due to unpleasantness.

[biker72]

Your GP will send you to a cardiologist. Pick one who is a runner or cyclist...or both.

+1
It does look a little noisy to me but a cardiologist visit is good insurance.

[geordanh]

thanks for the great feedback guys. I'm using a powertap powercal (just the heart rate function) and a garmin 510. Data looks more or less the same in connect and strava. Have a dedicated power meter for power.

I might go pickup a different brand heart rate strap and try that in the interim.

[dem]

Make sure your Garmin is set to "1 second" and not "smart sampling" too, just for consistency (I doubt it will matter, but..)

Definitely strange looking data - I have never seen that in my history.

[shovelhd]

Well, it would be a good idea to compare to another HR monitor.
Also compare your HR to: http://www.heart.org/HEARTORG/HealthyLiving/PhysicalActivity/FitnessBasics/Target-Heart-Rates_UCM_434341_Article.jsp#.WI_gBBjMzNw
AFAIK, your max HR (during intervals) s/b 220-age.
You should try to keep your HR below the max.

.

That metric does not apply to trained athletes. 220-59 is below my LTHR. My max is 193, or was 2 years ago.

OP, see a cardiologist, who may prescribe a stress test. Personally I think it's a bad HRM. Look at the Wahoo Tickr.

[Tandem Rider]

Check your batteries, DAMHIKT.

[Tony T]

That metric does not apply to trained athletes. 220-59 is below my LTHR. My max is 193, or was 2 years ago.

OP, see a cardiologist, who may prescribe a stress test. Personally I think it's a bad HRM. Look at the Wahoo Tickr.

Good point, but when doing interval training, should one "feel like I'm about to die by the end of one of these intervals"

I ask because I just started indoor interval training a week ago, so maybe I'm not pushing myself hard enough (I'm working up a good sweat, but I don't feel overly extended)

[mg2ride]

Similar situation for a good friend. He ended up having an arrhythmia.

Getting it checked by a cardiologist is the right move!

[kramnnim]

Under $25, free shipping. http://www.buydig.com/shop/product/GRHRM/Garmin-Premium-Heart-Rate-Monitor

[shovelhd]

Good point, but when doing interval training, should one "feel like I'm about to die by the end of one of these intervals"

I ask because I just started indoor interval training a week ago, so maybe I'm not pushing myself hard enough (I'm working up a good sweat, but I don't feel overly extended)

It depends on the interval and your fitness level. If I had a set of five, and completed four at target and fought to the finish for the last one, I called that success.

Did you complete a test, and do you think you gave it a realistic 95%?

[geordanh]

thanks guys. I just picked up a garmin. Hopefully it's the meter. :)

[martl]

AFAIK, your max HR (during intervals) s/b 220-age.
You should try to keep your HR below the max.

That is a rule of thumb, a very general one, and not one that is very helpful. When i was 35, my max HR was ~210ish and that of my same-aged riding buddy was ~175. We both were in perfectly good health. Apples and oranges, or, as my cardiologist put it: Some people have short noses, others have long noses.

I +1 the advice to see a doctor who has first-hand experience with power/endurance focussed sports. Some who don't have been known to panic when encountering a patient with a rest HR below 40 or who isn't incapable of pushing more than 150W on the ergo.

[Tony T]

It depends on the interval and your fitness level. If I had a set of five, and completed four at target and fought to the finish for the last one, I called that success.

Did you complete a test, and do you think you gave it a realistic 95%?

By a test, do you mean an FTP test? Yes, did the TrainerRoad test. This is new to me, so I can't really say if I gave it 95%

[benb]

I've never seen my HR or HRM do that.. my heart rate does not change rapidly at any HR up to my max and I have seen plenty of bad behavior from the HRM in certain weather conditions, but nothing like that. What I've seen out of my old Bontrager ANT+ Strap with a Garmin device was in dry conditions at the beginning of the workout I'd see crazy high HR values (225+) at the beginning of the ride that I could take my pulse manually and realize were way off, real HR was more like 135-150. I haven't seen that out of the Garmin HRM-Run I just started using this season.

I did hill climb intervals yesterday, here is a graph where I'm above threshold the whole interval, it's still very smooth.

I thought 220-age was seriously debunked. I'm 39, so that'd put me at 181. This graph I go to 182, and this didn't feel hard at all, HR is high early in the season for me, I'm pretty sure I can go to 190-192 still. If I get really close to my max I start to get a weird cold sweat feeling, it hurts like hell. I've only really done it on mountain climbs that were > 10% average grade and I was under geared, then I'd hit a spot that was 15% grade and just kill myself trying to stay on the bike.

[martl]

I thought 220-age was seriously debunked. I'm 39, so that'd put me at 181. This graph I go to 182, and this didn't feel hard at all, HR is high early in the season for me, I'm pretty sure I can go to 190-192 still. If I get really close to my max I start to get a weird cold sweat feeling, it hurts like hell. I've only really done it on mountain climbs that were > 10% average grade and I was under geared, then I'd hit a spot that was 15% grade and just kill myself trying to stay on the bike.
The gearing is (almost) irrelevant within quite a wide range - on anything > 4%, climb at a steady height meters/min and you get the same HR, regardless wether you're spinning at 40/min or 100/min.
Max HR *is* a function of how well rested one is, though.

[adrien]

It could also be the strap.

I had the worst time, with readings ranging from zero, to 30, to 312. Turns out a few folks don't get along with Garmin straps. I switched to Bontrager straps (who knew) and now my readings are not so crazy.

But yes, see a cardiologist (for athletes -- been through this) and have them do a stress test.

Found this on the straps:https://www.dcrainmaker.com/2010/08/solution-to-heart-rate-dropoutsspikes.html

[mjalder2]

By a test, do you mean an FTP test? Yes, did the TrainerRoad test. This is new to me, so I can't really say if I gave it 95%


It could be that the intervals you're doing, particularly if you're in a base plan, aren't supposed to feel like death. VO2 Max intervals, sure. Sweet spot intervals, maybe not.

The other possibility is that you underperformed your test, which is exactly what I did on my first FTP test. Then all your intervals would feel rather easy.

Which plan are you doing with TR?


Sent from my iPhone using Tapatalk

[Tony T]

It could be that the intervals you're doing, particularly if you're in a base plan, aren't supposed to feel like death. VO2 Max intervals, sure. Sweet spot intervals, maybe not.
Which plan are you doing with TR?


Sweet Spot Base - Mid Volume II
So…. looks like that's it.

.

[mjalder2]

I'm on that plan too. I knew I blew my FTP test when over-unders were more mentally taxing trying to hit targets rather than trying to not die. I would try turning up the intensity a little bit and see if that really makes it hurt or not. FTP tests should make you feel pain.

[benb]

The gearing is (almost) irrelevant within quite a wide range - on anything > 4%, climb at a steady height meters/min and you get the same HR, regardless wether you're spinning at 40/min or 100/min.
Max HR *is* a function of how well rested one is, though.

You're talking about a grade that is shallow enough you get a choice how fast to go.

I was talking about places that are so steep that if you have normal road gearing you only have 2 choices, leave nothing on the table and probably hit your max HR, or walk. Or a combination of the 2, try to ride it, hit your max HR, have to get off the bike, watch your HR not recover as you walk up the hill cause it's so steep.

Gearing is not irrelevant on those summit roads unless you brought parts to change your gearing or came with your bike specially prepared.

[martl]

You're talking about a grade that is shallow enough you get a choice how fast to go.

I was talking about places that are so steep that if you have normal road gearing you only have 2 choices, leave nothing on the table and probably hit your max HR, or walk. Or a combination of the 2, try to ride it, hit your max HR, have to get off the bike, watch your HR not recover as you walk up the hill cause it's so steep.

Gearing is not irrelevant on those summit roads unless you brought parts to change your gearing or came with your bike specially prepared.

You deliver a given Wattage at a given HR, which will, system weight factured in, give you x HM/min.
Whether you do that at 40/min or 90/min is ireelevant.

i limited to "within a wide range" because a flat climb <4-5% can be ridden fast enough to make wind resistance count, so a significant part of your total W produced goes there and the "height/min" is no longer the dominating measure to compare.

Above 16-18% (which is very rare resp. almost impossible, when we are talking longer average rate, to find on roads) the power output gets so unsteady (i.e. cadence gets too small) with any kind of gearing to measure with common power meters anyway.


*)this is my experience doing long hillclimb contests on long to very long courses, anything from 150m height diff to 1800m (stelvio) using an SRM. All of these flat-out at maximum possible HF (shorter hillclimbs at personal max HF)