WebFootFreak

I got a new toy this week: a Polar M200 watch. It does what I need beautifully.

Okay, to the pertinent information. I was on my exercycle last night (cheapie Schwinn 130 upright), and for that 45 min session, my heart rate was flat (for lack of a better term), and never got over 104. That absolutely does not equate to the effort I felt I was putting out. By comparison, my run on Wed topped out at 131bpm and my swim yesterday topped at 144bpm. I definitely felt that I was putting more effort into the bike that the run or swim. I'll have more data to compare to by next week...

Oh... the question... Given my general lack of fitness, why would my heart rate be so low when the perceived effort is so much?

HerrKaLeun

It is generally known that HRM are just guess tools to estimate effort (or your calories burned).

The heart pumps blood that transports oxygen/CO2 and fuel/exhaust products. A larger heart will pump more at each stroke. Also your blood composition determines how much fuel/oxygen one liter blood can contain. In addition your muscles and brain also use fuel and store byproducts int he cells. So added effort doesn't equate immediate HRM increase. There also is the anaerobic metabolism that doesn't rely on blood flow directly. On the other side if you are under stress, you don't use up energy, but HR increases just in preparation of potential need.

The heart is just an auxiliary device to your muscles. Like the fuel pump in a car. no one would measure hp-rating of a car by measuring the fuel pump current. the only reason HR is measured is because it is easy to measure. If you somehow could measure actual fuel and oxygen rate, that is what you would use.

Schwinneffect

I've observed that my heart rate varies a lot even when I try to hold the work load rate in Watts and cadence constant. My heart rate will typically start out at around 100 bpm, and then creep up to 135 or so. After the ten minute mark it slowly increases to about 155 if I don't back off. If I do the same workload while fasted my heart speeds up sooner. Caffeine raises it a bit too as does a lack of sleep. Perhaps this variation had to do with all the other stuff the heart must power in addition to legs.

zjrog

I notice significant variances in heart rate number between ,y Samsung Gear Fit 2 watch, my phone's sensor and my Wahoo Tickr X HRM belt.

I also agree with perceived effort and HR don't seem to match.

I'm beginning to look into Heart Rate Variability as a lifestyle tool. Good science around it, still wrapping my head around how to use that info.

WebFootFreak

I appreciate the replies. I'm with you zjrog. Heart rate and RPE are my only two data sources right now and I'm just trying to make sense of it all.

BengalCat

We need a little more info to respond fully to your question, (which is a great one.) As you know swimming, running, and cycling are not equal in the load they put on your heart and muscles.

In lieu of a direct response here is the best overview of heart performance in different exercises. I think the info is fantastic and will be a step in getting you closer to fully finding out what you seek.

​​​​​​https://www.bicycling.com/training/a...-myths-busted/

There is one thing that for me as an individual that has a big impact on my heart rate response to exercise, especially higher prolonged intensity such as climbing, and that is how long my warm-up ride is before I climb. For some reason, I take a LONG time compared to my peers to warm up. It takes me a minimum of 45 minutes riding before I am in the right condition to do my best or most efficient strong effort on a category 3 or 2 climbs. And it seems my heart and muscles have separate warm-up requirements.

Miele Man

I have a portable blood-pressure monitor that uses an inflatable cuff. It was recommended by my doctor who stated that finger-tip monitors aren't as accurate. I sometimes take it with me on a ride as I sometimes find it interesting to check my blood pressure at stops on a ride after riding intensley. I get my BP and my heart-rate.

Cheers.

Trakhak

Lower heart rate at higher perceived effort on an exercise bike than during running or swimming often means that the exercise bike's resistance setting is too high.

Many people make the mistake of thinking that higher resistance settings increase the benefit of an exercise bike workout. That's true for anaerobic exercise, such as weightlifting, but that's not how aerobic exercise works.

Experienced cyclists usually end up pedaling roughly 85 to 95 rpm. Not coincidentally, that's about the range of the running pace for most runners.

To get the best workout on your exercise bike, start with the resistance setting very low. Begin pedaling at a cadence that approximately matches your running pace (probably somewhere around 90 rpm). Then gradually bring up the resistance while maintaining the same brisk pedaling speed. You'll find that it won't take much resistance to get your heart rate up to where it's close to what you see running and swimming, or even higher.

For a real-life example, just this morning I did an hour and a half of a particularly brutal indoor riding session using a smart trainer (which adjusts the resistance based on a plotted curve). Average cadence was 100 rpm; maximum heart rate was 179 (very high for me, at 68 years old).

zjrog

As I started my path to Gastric Sleeve weight loss surgery, I had to have a sleep study, and a cardiologist consult. Both of these scared the crap out of me. I wound with CPAP and immediately became obsessed with numbers. And the Cardiologist put me in a cardiac rehab program to keep me from having a heart attack.

I have used a HRM belt for years, but now it means something. And as I mentioned, I'm looking at HR Variability as an overall indicator of health.

As I am down nearly 140 pounds from my heaviest, I have plateaued. And having tough time getting motivated. So maybe I ought to look at all the data and metrics I've been collecting the last 18 months. I mean, My BP cuff is Bluetooth, my scale too. Smart watch gives me O2 sats. Power, speed, cadence and heart rate are bluetooth or ANT+. About the only thing missing is a way to measure my VO2.

For a numbers/metrics collector, I hate charting and spreadsheets. Strava can only collect and show so much of that which I collect...

I used to run. Due to my back injury and ankle needing fusion, that will never happen again. So I can't say if running has a higher or lower perceived effort vs heart rate for me anymore. But I could certainly collect data to show it if I could run...

brawlo

If you are new to riding or generally unfit, then RPE will be high for a given effort. Unless you have any specific heart issues, you will probably find that your max HR will be a lot higher than what you have experienced. RPE may be high in the case you mention due to the duration of the exercise. Build up to it, or just persist and you will get better at it. What feels like RPE 10 may feel like RPE 5 in a month or so.

In my own experience, HR can be a kind of poor man's power meter. The only problem is that it's not as responsive as a power meter. I find that HR can take a good minute or even more to catch up with your effort level. Through experience and time monitoring my HR I know the regions where I can push harder, where I can maintain effort for an extended period, and towards the top part where I know if I spend much time there, I'm going to implode. Then there's also the dreaded zone where your legs feel like RPE 10 but your HR is in the zone where you know you can push harder. That's the time to just stop and rest.

Clyde1820

There's a reason it's called perceived effort and not actual effort. A lot can vary from one run/ride to the next. Breathing, form, temperature, differences in elevation changes in comparison to when/where along the route we hammer it, etc. Watts versus RPE, IOW.

Back when I used to run hard, years ago, I often noticed that on cooler days when well-hydrated it was possible for me to run extremely hard on a hard route/course while still keeping pulse rate lower than on a typical hard run. I'm pretty sure environmentals and hydration can affect things. Might well be better tied to, oh, deeper breathing, less-efficient form under certain loads, and whatnot. ("Apples to apples" comparos might be very difficult to achieve, in practice, given all that can vary from one run/ride to another.)

I also used to notice that I could overheat more easily if my cadence skyrocketed due to a given route's requirements, as compared to outright elevation changes. But then, I was extremely strong on hills and "tougher" sections and never felt like I needed to max-out on the tough stuff, whereas I most definitely felt that I had an upper limit to my cadence before it'd start getting me to overheat, overexert. RPE could feel like floating along on a "tough" course, but RPE could feel like a bear if my cadence went too high. "Grinding it out" (strength-wise) was always vastly better for my own perceived effort, on a given course, instead of boosting my foot speed and attempting to get more-efficient on that same course.

Don't forget: blood flow is about two things ... oxygenation/fuelling, and "air conditioning." And if the body doesn't have to work so hard at a given level of effort on a "standard" route due to being cooler, for example, then it should follow that the heart wouldn't have to pump quite so hard to stay in the zone. Perhaps less, too, if breathing more-fully and deeply, at a given level of work.

At the gym, there's an elliptical machine I occasionally use that has a program called "Constant Watts." It'll keep adjusting the resistance level on me to ensure the watts/output keeps within a narrow range. I burn vastly more calories (according to the machine's count) on the "Constant Watts" program than by simply goosing the difficulty and cadence myself. Though, interestingly, under the constant watts doesn't result in a noticeably higher average pulse rate than when I'm adjusting cadence and difficulty myself, despite the higher average watts and despite the much higher calorie count over the same amount of time. Anecdotal, sure, but ...

Can't say whether it'd translate to a bike, though I don't see why not.

WebFootFreak

Again... thanks for all the responses. Y'all have given me quite a bit to digest.

I should have given a touch more info...
I am not new to biking, but 2015 was my one and only year over 1000 mi. 14 and 16 were in the high hundreds and other than a small triathlon last June, I've only just started getting serious again. I really just figured that as hard as I felt I was going, it would show up in my heart rate

DrIsotope

My "average summer cycling heart rate" is probably 15bpm higher compared to cooler months. Regulating body temperature is tough business when it's very hot and very dry. And by dry I mean so dry that the act of breathing is dehydrating me, because I'm sucking in +100ºF air @ 6-8% RH.

Regardless of time of year, I cannot rely on HR as any sort of indicator of effort. I don't sleep nearly enough, I don't drink enough water (constantly dehydrated, pretty much) and thanks to daily temperatures fluctuating +/-20ºF on any given day, I can feel good one day and be way down on power, or feel sluggo another day and be up 20%. HR isn't even really a decent indicator of conditioning, as it's just determined by too many factors. W/HR is a crazy stat to look at over the long term, because it's just all over the place.

So why do I continue to strap that HR monitor on before every ride? HRR. Heart rate recovery is exceptionally valuable, particularly when riding in heat. Regardless of what number is showing when I'm moving, I know that my HR should drop at least 8-10bpm as soon as I come to a stop, even if that stop is only for a few seconds. If I come to a stop and it sits on the same number... things are on their way to a bad place.

zjrog

When I lived in the high desert, Ridgecrest, the days over 110 F were tough to ride in. 3 and 4% RH. Above 110, you barely feel yourself sweat, as it evaporates off you just walking. I imagine, other desert dwellers will say much the same.

I agree with you on the recovery aspect watching my HR.

squirtdad

HR is a measure of that and not work, and it has a loose relationship to how much work you are doing (effort) but you need watts to measure work

I use HR in training to tell me if I am in the range I want to be in......I can think i am working hard, but HR shows I can work harder to get into the range I want (or tells me if I am above the range I want even in id don't think I am working that hard)

I also use resting HR as a rough measure of aerobic fitness

and of course as you get in shape you have to work harder to get your heart rate up so that complicates things a itt

I find that I feel like I am working hard on a rowing machine, but the watts (or actual work vs percieved) are not that high and my heart rate is not that high, I would not be surprised to see similar on a stationary bike, as some of the effort you doing when riding on a road like balancing is not there on a stationary trainer

Running will absolutely put my HR up and up fast. It is load bearing and engages more muscles than biking

Swimming is complicated in the getting an accurate HR is difficult....the garmin requies a chestband and then only transmits the when the swim session is done. Also how good a swimmer your are makes a difference, I have to push hard to get my HR up, but I have also worked for ages to make by stroke more efficient.....

Beachgrad05

The entire reason I have power meters (Stages left crank) on both my carbon bikes is this. My HR is super low and is NOT a good measure of how hard I might be working on a given ride. I didn't put one on my steel commuter as don't really care about power on my 8 mile ride to and from work. It is also the bike I use on my KICKR so no need for it there either as the KICKR handles the power.

bikebikebike

Add to that the fact that many clydes and older riders are on Beta-blockers and RPE starts looking good.
Garmin has started promoting respiratory rate monitoring through the HRM R-R interval so this might even get more practical