massive heart rate fluctuations while at same pace

I am somewhat new to heartrate monitors, but not running. I have found this strange phenomema occurring at the beginning of my runs as well. The only thing I can think of is that your body is adjusting to the initial work, which I think is anaerobic (even though you are going for an easy run). Your HR increases to match this an. work until the metabolic wastes are cleared, and sufficient oxygen can be supplied for the aerobic system to match the energy demands of the run.

Can anyone smarter than me help us out with this?

If it happens at the beginning of your run, it's most likely your skin is dry and the HRM isn't getting consistent readings.

I've found it's o.k. when walking and perhaps at the very start of the run and then you might get erratic readings - sometimes very high, then after a km or two it settles down and gives consistent readings. Tends to happen to me more in the winter than summer.

If you have a cloth HRM strap, then you should wet it before the run - at least that seems to do the trick with my polar rs300x, but it's summer here in NZ, so plenty of sweat after a brief warm up helps too.

Some more info here:

http://www.dcrainmaker.com/2010/04/troubleshooting-your-heart-rate.html

Thanks guys. This has actually been happening right around a half hour in each run. I'll be going the same pace under same conditions and bam....heart rate goes WAY up. It also has happened on the treadmill inside while wearing the same HR monitor.

You could have a

svt but you would find it more difficult

to breathe if that's the case.

Geezer1 wrote:

You could have a

svt but you would find it more difficult

to breathe if that's the case.

svt?

Geezer1 wrote:

You could have a

svt but you would find it more difficult

to breathe if that's the case.

I see what SVT is. It's weird that I feel the exact same when it happens. My breathing feels the same and everything, pace...everything but the number on the watch.

Geezer1 wrote:

You could have a

svt but you would find it more difficult

to breathe if that's the case.

marke wrote:

I see what SVT is. It's weird that I feel the exact same when it happens. My breathing feels the same and everything, pace...everything but the number on the watch.

Check it with your finger next time to verify the number on the watch.

long sox wrote:

If it happens at the beginning of your run, it's most likely your skin is dry and the HRM isn't getting consistent readings.

I've found it's o.k. when walking and perhaps at the very start of the run and then you might get erratic readings - sometimes very high, then after a km or two it settles down and gives consistent readings. Tends to happen to me more in the winter than summer.

If you have a cloth HRM strap, then you should wet it before the run - at least that seems to do the trick with my polar rs300x, but it's summer here in NZ, so plenty of sweat after a brief warm up helps too.

Some more info here:

http://www.dcrainmaker.com/2010/04/troubleshooting-your-heart-rate.html

I appreciate your reply, but I don't think it is a connection problem as the reading before is accurate. The unusually high HR at the beginning last for about 5 minutes or so, then settles into a more "normal" reading. My wife has also experienced this, as well as some athletes that I coach. It is strange and I would like to know the cause of it.

uh huh wrote:

I appreciate your reply, but I don't think it is a connection problem as the reading before is accurate. The unusually high HR at the beginning last for about 5 minutes or so, then settles into a more "normal" reading. My wife has also experienced this, as well as some athletes that I coach. It is strange and I would like to know the cause of it.

It's called sweat and it has salt in it. You don't sweat for the first 5 min. It is common and not strange at all.

You could have an arythmia. I have periodically had asymptomatic a-fib (atrial fibrilation), I don't have any problems breathing and have never had to be cardioverted when it occurred, only the weird readings on my HR monitor tipped me off.

I am on medication now, and this has not affected my training or performance. When you get the high readings, what is your pulse like? If it is fluttery, irregular you could have an arrythmia and not a problem with the monitor.

Although not life threatening, this can be serious and should be checked out. Once you start getting irregular beats, even temporary, you become more prone to more frequent and longer bouts. Therefore, it is best to get it addressed early. Since it happens sporadically, I had to wear a monitor for a couple of weeks to catch an episode so the doctor could understand it. I did have two longer episodes (first time was almost 12 hours) and they put me in the hospital because they did not know what was going on (I think they thought I had been taking cocaine or other drugs).

This is becoming more common, especially with endurance athletes. I first developed problems following training for an IM (doing 12 - 15 hour weeks). I gave up the high volume training (usually stick to less than 10 hours) and coupled with the medication seem to be generally fine. I still get an occasional skipped beat or flutter, but maybe once a month for a few seconds, usually just when at rest.

If you can stand the triathletes, go over to Slowtwitch.com, there have been numerous discussions about this, symptoms, etc.

thanks very much.

should i be concerned about training between now and a dr.visit? would you recommend going right to a cardiologist?

There may be a perfectly innocuous explanation for the increased or apparent increased rate, but as someone who has had and continues to have serious heart problems, I'd suggest you not take a chance. I'd try, though, to find a cardiologist who has treated endurance athletes.

Before going to the doctor check whether the reading is reasonably accurate or not. You can do this by just counting the beats in your wrist or throat as you run for 30 seconds (when the reading on your hrm goes high).

If the perceived effort is not changing much then it's unlikely that you'd have that big a variation in actual heart rate unless there's some sort of real issue.

Heart rate does tend to drift up at the same pace through a run, but not to the extent you're talking about.

Thanks guys. Can't believe I didn't think to just check with my finger.

After you figure out that your heart isn't about to explode (it's not... if you feel the same, your HR is likely the same. People who experience tachycardia know it, for the most part):

Garmin HRMs have three pretty common failure modes:

1) Not enough moisture to get good skin contact (lick the pads before you put it on).

2) Static electricity buildup on the HRM itself (common cause of the "my HR is really high for the first 5 minutes of the run" problem).

3) Very wet shirt starts slapping against the HRM sensor and pads every time you take a step -> produces HRM that looks suspiciously like your cadence. (remove shirt. does not work so well in winter.)

I usually get #2 at the start of a run and #3 if it starts raining or I'm doing a long/hard enough workout that I get drenched in sweat. Fickle little beasties, they are. I felt like the older harder plastic HRM straps were less susceptable to these problems than the fully fabric straps are, but they sucked in different ways.

How old is your HRM?

What condition is the band?

On my easy 10 miler this AM my HRM went crazy . . . I averaged 189bpm and had a max of 243. I read part of this thread before I ran . . . so I took my HR by hand - got a reading of about 100 after stopping to take the my HR.

Mentioned this to a friend. He thought it was the band not making optimum contact and that the numbers represented my cadence/running motion as the HRM made contact with my skin and then lost contact.

I have had those runs where my HR skyrockets around mile 1 for about 10 minutes. This has always been a contact issue. Once I get sweaty enough, I get good contact and the numbers return to normal.

The last thought I have is that sometimes you get interference from outside sources - power lines, maybe garage remotes etc . . .

I think I need to tighten my band when this happens - or just before every run for better contact.

My friend suggested the ointment used by along with ultra sound.

jery,quack: thanks for the thoughtful replies. I wish I'd read them before my run today. I tried to run MUCH slower today and my heart rate was slower but still jumped about thirty beats a minute after about fifteen minutes and refused to come back down this time. I couldn't get a fix on my pulse manually but my shirt was soaked and the cadence thing makes sense. I am going to try and strap this thing on tighter next time and see if that fixes it and report back and maybe this helps others.

Just an FYI, at the start of my run my HR is low and gradually gets up to my desired rate and then suddenly skyrockets at either fifteen minutes or half an hour.

marke wrote:

jery,quack: thanks for the thoughtful replies. I wish I'd read them before my run today. I tried to run MUCH slower today and my heart rate was slower but still jumped about thirty beats a minute after about fifteen minutes and refused to come back down this time. I couldn't get a fix on my pulse manually but my shirt was soaked and the cadence thing makes sense. I am going to try and strap this thing on tighter next time and see if that fixes it and report back and maybe this helps others.

Just an FYI, at the start of my run my HR is low and gradually gets up to my desired rate and then suddenly skyrockets at either fifteen minutes or half an hour.

Another option is to find a treadmill with HR grips and run a nice steady pace and check your HRM against the treadmill HR receiver.

I find the StarTrac brand treadmills read HR within 1-2 beats of my Polar RS800.

See if it happens only when you're under power lines.