heart rate question

[suzieqtwa]

I need your advice because my heart rate over the past few months has gotten real low when I am cycling. I commute to work, and I do longer rides over 40 miles on the weekend days.



My normal average after a vigorous ride was always in the 120s or 130s, with a high around 160 or 170. Now my average heart rate is below 110.



For example, today I biked with Ellen and Darcy. We did a 55 mile loop with lots of head wind and rolling hills, so it was a physically demanding ride. We stopped for a nice lunch. At the end of the ride, both Ellen and Darcy had average heart rates in the low 130s, including the time spent at lunch. My average heart rate was 105.



I don’t know why my heart rate won’t go up when I ride. I’ve examined everything. I’ve taken rest days. I make sure I stay hydrated. I eat enough. I push myself on every ride, and I even experimented with cycling in higher gears.



Can you tell me what is happening?



Suzie

[Zen]

You're not taking any meds, are you? ( probly not, I had to ask)

[han-grrl]

How does it feel when you ride at various intensities?

[suzieqtwa]

No ,I'm not taking any meds...sometimes I feel tired when I'm biking ,I don't give it my all ,but yesterday when Darcy ,and Oxyback (Ellen) ,and I rode, we all stayed together ,and did go up against headwinds ,and hills. I wasn't out of breath or anything ,but I did give it my all. I don't think anything is wrong with my HR monitor ,as I ran 2 miles to test it ,and my avg HR was 132 for 18 minutes? I'm going for a short 15 mile ride now ,and I'm going to try ,and work real hard. I just don't understand why all of a sudden it has dropped so low.

[Mr. Bloom]

If I ran two miles, my heart rate would be off the chart...

Is it possible the reading is simply a result of your physical conditioning?

[DarcyInOregon]

If I ran two miles, my heart rate would be off the chart...

Is it possible the reading is simply a result of your physical conditioning?

I don't that is the answer. Suzie and I have been riding together several times a month for almost a year, including event rides. For all of the rides, we were within a fraction of each other on the heart rate statistics. I say this because we are the same age, except Suzie is lean and I carry excess fat. Then all of sudden, on all of her bike rides, either alone or with Ellen and me, short rides or long rides, her heart rate would not go up. For example, the three of us did an event ride in June, about 73 miles, and the weather was cold, there was constant heavy rain, there were real steep hills, there was wind, there were rolling hills, and so on. Suzie ended up with an average heart rate of around 107 and Ellen and I were in the 130s.

I don't understand why this is happening to Suzie. I told her it is almost like her bike rides are useless because she isn't getting any meaningful cardio. I can go out and walk my dogs on the hills around my home and get a higher average than her bike rides. The top cyclists train via their heart rate. They are in superb condition and they are able to get their heart rates up. So why can't Suzie get her heart rate up?

Darcy

[RoadRaven]

Don't forget that a "symptom" of getting fit is a lower heart-rate when exercising. Like MrS says - is it your increased fitness?

The only other reason where HR doesn't go up that I can think of is when you are getting sick... It will go up as expected but reach a plataeu earlier than you think it should and it doesn't matter what you do, it just will not go higher - mind you, this usually goes hand in hand with an elevated resting HR.

I seriously think it is most likely a sign of your fitness level... you are not sick, you are on mo meds, you have been "pushing" yourself on some of your training rides... I think your body has responded to your requests and increased its ability to cope with stress (ie, exercise) more effectively!

[DarcyInOregon]

I seriously think it is most likely a sign of your fitness level... you are not sick, you are on mo meds, you have been "pushing" yourself on some of your training rides... I think your body has responded to your requests and increased its ability to cope with stress (ie, exercise) more effectively!


It would be nice to assume it is fitness level. But then the question is why does the heart rate not go up on long, vigorous rides? A person can be fit, but when you push yourself and continue to do activity that is more vigorous than what the body is accustomed to, then the heart rate will go up. That is what I am saying, that Suzie is continuing to increase her miles, riding more often, climbing more hills, and for everyone else, despite what level of fitness, their heart rate will increase when they push themselves to do more than what they did previously.

To say it is fitness level almost implies that Suzie can do more on her rides, like go faster, or go more miles, or climb more hills, that she isn't doing enough. I ride with her, and she looks pretty tired to me at the end of the long rides. There are times when she leads, and times when she falls behind. Sometimes she gets to the top of the hills first, and other times she doesn't. What I am saying is she appears to be just like Ellen and myself, pushing herself as much as she can, but being sensible about it so that she can finish the distance.

On the 73-mile event ride I mentioned, Suzie and I were both exhausted. We had a long car drive home, so I was with her during that time and could see for myself how tired she was. It shows she gives her rides her maximum effort.

Darcy

[Zen]

I don't know. Are you sure the monitor is working? Look at the heart rates of the TdF riders. Even they red line it once in a while.

[RoadRaven]

Darcy - I was writing my reply as you were posting
Good to have some more insider info

If you both seriously think that this is not a result of increased fitness, then I would get a doctor who knows hearts... or a sports doctor who knows sports physiology... to check it out.


EDIT cause Darcy and I cross postsed again! I blame my dialup - connected at 14.4kbps this morning!


I don't agree that to say fitness means she can push her heart more and more...

What I am trying to say is if you continually train at a level where you push your heart occasionally but regularly, then your body responds and makes your heart more efficient. And what she describes in her original post is what happens to me now.

For example:
When I first started biking, any slight rise would have my heart up over 150bpm, often into 170s
Now I can climb 6-8% gradients in a steady training ride and my HR rarely goes over 130bpm
The only time I can get it as high as 160/170 is when I am racing up a hill, or in a time trial race, or doing sprint intervals...

I am not suggesting Suzie do more on her rides, and in fact that can be detrimental to her training - the boys in le Tour/Giro etc... the girls in the World Cup... they do hours of riding a day, yes, but not at the most intense levels

[DarcyInOregon]

I should say I get rides with lower heart rate averages, below 110. But they are the rides when I am already tired, or too many days in a row, or I am not pushing myself. When I am rested and I push myself, my heart rate goes right back up.

For Suzie, every single ride is now below 110, whether the ride is 20 miles or 60 miles. So what can she do to bring her heart rate back up into the cardio range? What do the professional cyclists do who at their maximum fitness level?

Darcy

[DarcyInOregon]

Thanks for understanding my concern for Suzie's well being. Can it be a function of something going wrong with the heart? I hope not.

Suzie says she has a doctor's appointment in October.

Zen, Suzie thinks the HRM is working because she tested it by going for a run, and got an average in the 130s, like normal.

I think Suzie is in great shape physically and yes, she has a high fitness level for her age. But I don't think the reason for the abrupt change in her heart rate is due to fitness level, because since it happened she has pushed herself with more miles and more hills and the heart rate remains low. She doesn't think she can go any faster or push herself any harder, so I don't think fitness level is the cause of every single ride having a low heart rate.

Darcy

[Zen]

Ahh, I wasn't focusing on the word average.
Never mind then.
Does the HR monitor show max HR?

[DarcyInOregon]

Raven, you describe a situation that is gradual, and that makes total sense. But with Suzie, it was like one day her average heart rate was in the 120s to 130s, then the next day it sunk below 110 and never went back up again.

And we challenge ourselves on the longer rides. We change the routes, go longer distances, do more hills, and so on.

I've experienced the lower heart rate on the same hills too. It is very gratifying to see. But for myself, I push myself harder and the heart rate goes back up.

Raven and Zen, what are the average heart rates for all of your rides?

Darcy

[DarcyInOregon]

Ahh, I wasn't focusing on the word average.
Never mind then.
Does the HR monitor show max HR?

Zen, Suzie will need to reply to that question. I asked her that yesterday, and she said it showed 275, so she thinks she had a cross-over from a power generator or another heart rate monitor. Ellen and I both had a high in the 160s. Suzie says her HRM shows a cross-over a lot.

Maybe the answer is she needs a new HRM.

Darcy

[Zen]

Raven and Zen, what are the average heart rates for all of your rides?

Darcy

Mine is in the "I don't care" range.
If it doesn't go back down then I might worry about it. If I think my head is going to explode, then I might worry about it. Maybe this winter when I start spinning on a regular basis, until then I'd rather spend my money (money? what money?) on a dog.

[SouthernBelle]

I think she needs to try another monitor before anything else. If she's getting interference it may be missing some beats, not her missing some beats. I assume this isn't one where she can download to a puter and look at a chart?

If someone has a Garmin Edge with a HRM she can borrow for a ride it would be worthwhile. She can upload to motion-based and compare her HR with her effort.

[roadie gal]

A few thoughts:

If there's a suspicion that it might be the HRM, then get on a spin cycle where you don't have to worry about crashing and see if the pulse, by feel, is correlating with the HRM. If not, your question may be answered.

Can she get her HR up to normal levels in another sport, such as running? If so, then I would think more about increasing fitness levels than a pathology, since her heart is capable of reaching a high rate.

Are there any symptoms associated with the (possibly) low heart rate while biking? They don't have to be chest pain or shortness of breath. If she's feeling like her legs are going numb, or lightheaded, then that needs to be checked out.

The Reader's Digest version of my story: I always had a low resting heart rate, in the upper 30's to low 40's. My actual max was correspondingly below my calulated max. A few years ago my resting heart rate started dropping into the low 30's and occasionally the upper 20's. My max went down to the mid 120's. I started having lightheadedness and a choking sensation with exercise. This progressed to the same symptoms with any exertion, like walking up stairs. I went to a cardiologist when I could no longer walk up stairs without getting short of breath. It took a while to diagnose, but my heart's pacemaking cells had quit. I am now the proud owner of an electronic pacemaker. I am also back to exercising as much as I want and even do triathlons.

Bottom line: If you can't easily see that it's the monitor or increased fitness then GET IT CHECKED OUT.

[suzieqtwa]

Hey,
I got up this morning ,and put the bike in high gear in the front (3 rings) ,and rode 21 miles. I gave it all I had ,and even had to stand up on all hills. I wasn't tired,but did pant going up some of the hills standing.
My avg was 115. My Max is usually 162 or something..that's consistent. I'm not fast...in fact I'm the slowest person I know. My avg over 20 miles-70 miles is always in the 13s. I feel great ,and I cant imagine what's wrong. The monitor is only about 5 months old. I'm not very good at using it ,and I did screw around with it a bit turning off the beeping sound....maybe there is something wrong with the monitor. My brother is a doctor...maybe Ill give him a call. Thanks for all the advise...Ill keep an eye on it.

[suzieqtwa]

Oh, my resting HR is about 48 ,and Im 53 yesrs old

[Skierchickie]

Maybe borrow someone else's HRM? Maybe even wear both at once, and see if they correspond? And maybe get to the doctor before October. I'd say (well, depending on what the doctor says), really hammer one ride (you said you weren't particularly tired on your 21-miler, and that you consider yourself slow). 162 doesn't sound like an exceptionally high max, so maybe you haven't found your true max, and are really really well trained at slower speeds.

Just a couple of thoughts - good luck!

[Mr. Bloom]

I understand the concern.

Have you done a manual count of your heart rate to verify the monitor.

I understand the concern and am intrigued by this...particularly, since if my heart rate was that low in exercise, I would assume it was improved fitness...so, I'll be interested in knowing the outcome.

I agree with prior posts, it may be time to see a doctor since presumeably, these symptoms would be easily replicated in a stress test.

Please keep us informed.

[RoadRaven]

Raven and Zen, what are the average heart rates for all of your rides?

My average? Honestly I do not know as I have been too lazy to work out how to find that info on my HRmonitor :p

I monitor my HR to push my lactate threshold in training, to ensure I race in Zone5, 5a & 5b (particularly in time trials) and to keep my heart rate low on active recovery rides.

In a training ride with hills my heart rate will be between 97bpm and 160bpm.

On moderate hills I climb at a steady training pace with a heart rate now of no more than about 120bpm... 2-3 months ago the same hills would have me shoot up over 138/145bpm. Although this change wasn't literally overnight, it did happen over a couple of weeks.

(When I started cycling about 3 years ago even moderate climbs would have my HR into the high 150s, 1602 ans even 170s.)

I am finding I am noticing changes in my heart responses seem to happen in stages... with plateaus... but this may be because I do not keep an every-ride-check on my average.

Sorry... not much use to you in terms of how you/Suzie use your monitors...

[RoadRaven]

I gave it all I had ,and even had to stand up on all hills. I wasn't tired,but did pant going up some of the hills standing.
OK... when I do this my HR goes up to high low 160s... in a race situation that would be high 160s and early 170s.



My avg was 115.
Remember that an average tends to err on the low side... a short period of time at 110bpm, would mean something like 3 times as long above 120bpm to bring your average back to 115 (mathematics is not accurate, but hope you get the jist).



My Max is usually 162 or something..that's consistent.
My max is 182. My last measured lactate threshold was about 160, but I am sure that has gone up and I am back to the science lab next month to get it measured again. My resting HR sits on 40... sometimes just under.
I am almost 42.


I'm not very good at using it ,and I did screw around with it a bit turning off the beeping sound....maybe there is something wrong with the monitor.
This does ring alarm bells - especially when Darcy posts that it seemed to work as expected when you went for a run... Check that out, and how it fits you (is your bra/crop top interferring with the position?).

But maybe have a chat with Dr Bro too...

[SouthernBelle]

One other quick thought: Is someone you regularly ride with wearing an HRM that interferes with yours?

[li10up]

Sounds like it may be the transmitter or receiver going out...or perhaps you are getting the transmitter and receiver too far apart somehow so it quits measuring some beats? Do you wear the receiver on your wrist or is it on your bike? Have you started standing more frequently which may put the two too far apart?

[traveller_62]

Have you recently picked up the volume or intensity of your rides recently? A couple of times this season I've been training too much (too long, too hard, too frequently). When this happens I find that I can't get my heart rate up to where I expect it to be even though I'm feeling ok otherwise. For me this situation signals muscle fatigue and a couple of days of complete rest have helped get me back on track.

Have you noticed an elevation in your resting heart rate as well? This is also a good measure of overtraining.

As the others have mentioned it is also a good idea get checked out by your doctor since this change happened relatively quickly.

Hope you get it figured out soon and that all is well.

- traveller

[Veronica]

So have you been to a doctor yet?

Thom's been worried about you since I first read your post. :)

V.

[smilingcat]

Please go see a cardiologist and do a stress test with EKG. Some offices are now equipped with stationary bikes in addition to the tread mill.

Unless you are uber fit ultra-athlete, low 40's heart rate, doesn't sound quite right. Also have someone else wear your HRM who knows what their HR is and see if it agrees with them. And for you to try theirs out. Compare the result...

And are you drinking lot of herbal tea by any chance? Like hibiscus flower tea? or something else. If you are, check with herbal medicinal books and also tell the cardiologist before the stress test. I sort of remember that the hibiscus flower has an effect on your blood chemistry and heart rate.

smilingcat

[PinkBike]

i would tend to agree with roadraven. the average may be low, maybe you spend a lot of time recovering. do you watch your heart rate when you're exerting yourself? what does the hrm show as your max after the ride?

if you hit a healthy max i would say you're fine, but i would really worry if you just cannot lift your heart rate.

call your brother!!!!

[ChickWithBrains]

Just to reiterate: you're not on meds, right? If you were on a beta-blocker for blood pressure, it prevents reaching your max heart rate as well as lowering pressure.

Don't stress about a stress test; it's unlikely that ischemia (lack of oxygen to your heart because of clogged arteries) are causing this without you getting totally winded or developing chest pain. That's not to say that it may not be something cardiac, but "the big scary one" is sort of unlikely.

When's the last time you had your thyroid checked?

If you haven't already, borrow a friend's HRM and go for a solo ride to MAKE SURE that it's not your monitor and interference with riding buddies!

Max HR with identical effort decreases over time as we age. And as we get fit. It doesn't make sense that your numbers would change dramatically between one day and the next, but you now compared to you 10 years ago would yield different max HR on identical field tests. Just to keep in mind.

[slmdunc]

Something similar happened to me with a heartrate monitor that was on my personal treadmill. All of a sudden, I couldn't go over 115. I didn't get it. I FELT like I was working hard, I was sweating... but it just wouldn't go up. Turns out - it was the monitor. Never worked right again after that. Not sure of the specifics of WHY it broke, or WHAT broke on it... but it wasn't me.

I hope that's what it is for you!