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Discussion Starter #1
Check this out: http://www.runworks.com/2014/02/running-vs-cycling-heart-rate/

Some of the main quotes:

"Most runners would probably agree that jogging at 60-70% of max heart rate is fairly easy: they can carry on a conversation without trouble, and maintain that heart rate for over an hour. But for some people, reaching the same heart rate while swimming or cycling may feel much more difficult, or even nearly impossible. Why?"

"Then I tried the HRM on some spin bike workouts. I cranked up the resistance, trying to bring my HR to the same zone as my easy runs, but the effort required felt extreme. It was like sprinting up a steep hill. My legs turned into blocks of stone, and I couldn’t keep going for more than a couple of minutes. Just for fun (this is fun?) I tried an all-out sprint with the bike at a high resistance setting, and found that I simply couldn’t push my HR beyond 162 on the bike, even as I was gasping for breath and sweating a river. After much experimentation, I finally settled on a resistance level that felt subjectively like a hard run, but still only raised my HR into the 125-130 range."

"What the heck is going on here? Why was the heart rate on the bike so different than the heart rate while running, when working at the same level of perceived effort? And what does the discrepancy say about the best way to combine training for running and cycling?

I did some research, and found that many other people have observed the same discrepancy between running and cycling heart rates, though mine was a bigger difference than most. This discussion mentions a 5% difference or ~10 beats per minute, this triathlon site refers to a 15 bpm difference in max heart rate, and this article talks about the discrepancy at length but doesn’t give any specific numbers. Intriguingly, though, it does mention that the discrepancy appears largest among runners with little cycling experience, and that pro triathletes with lots of cycling and running experience show little discrepancy in heart rate between the two activities.

Unfortunately, I never found any source that gave a really satisfactory answer for the discrepancy, but there are two general theories that come close to an answer when they’re combined. Theory #1 seems to be that fewer muscles are used while cycling vs running, so the demand for oxygen isn’t as high, and the heart doesn’t need to beat as fast. Theory #2 is that the leg muscles of a runner-turned-cyclist are comparatively weak, and it’s ultimately muscle power that limits cycling performance, not aerobic capacity. Taking a step back, these theories could almost be viewed as two sides of the same coin. In essence, they’re both saying that the ability of the heart to pump oxygenated blood to the leg muscles is not what determines the upper limit of cycling performance (and presumably perceived effort). More succinctly: cycling is a strength activity, not an aerobic activity."

"Unfortunately I find this answer vaguely unsettling. If I do a spin bike workout at the same level of perceived effort as my easy runs, and my HR during the workout is only 120, what part of my body am I actually strengthening? Will I get any meaningful aerobic benefit out of it? Or am I just training cycling-specific muscles, which isn’t a goal at all? I’m going to keep digging and see what more I can learn."

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This basically agrees with my experience. In summer I started out with zero running/cycling ability - call this my June cycling fitness. From then on I did 2 months of cycling and basically no running. Naturally my cycling ability improved a lot, but my running was still very poor. From then to now, I barely cycled and started running more, and my running ability has improved A LOT. But even inspite of that, my cycling ability has literally reverted back to my June cycling fitness(!!!???), even though back then I had zero cardio ability whatsoever, unlike now!

It's all very baffling and interesting at the same time. Hopefully you find it as useful as I did.
 

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nice that's for the share, I was only on about this the other week. I had trouble reaching Zone 2 on my turbo when doing intervals, I assumed that you had to work to a different set of HR zones different to when running, but this makes sense.
 

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Same here. When using my excercise bike, I can get my HR into the 130's, which is less than 75% HRM, but any more than that requires extreme resistance level, and my legs can't take it.
 

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Discussion Starter #4
Yeah Andy, that's how I felt on my 1h bike rider earlier. At 150 bpm when running, I don't even notice I'm breathing, I'm jogging very slowly and not really putting any effort in ... but on my bike at the same 150 bpm (at least today, since I haven't rode much in the last 3 months), I was noticeably breathing and my legs were starting to burn to maintain it. I maintained it ok, but it was A LOT more perceived effort.

I also found the quote "cycling is a strength activity, not an aerobic activity." interesting, because what if this also applies to running (in a relative sense)? Perhaps a higher level of strength would allow a runner to attain an even higher HR, and perhaps the current "max running HR" is not really a true max, much like a stronger cyclist could attain/sustain a higher cycling HR than a weaker one.
 

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Yeah Andy, that's how I felt on my 1h bike rider earlier. At 150 bpm when running, I don't even notice I'm breathing, I'm jogging very slowly and not really putting any effort in ... but on my bike at the same 150 bpm (at least today, since I haven't rode much in the last 3 months), I was noticeably breathing and my legs were starting to burn to maintain it. I maintained it ok, but it was A LOT more perceived effort.

I also found the quote "cycling is a strength activity, not an aerobic activity." interesting, because what if this also applies to running (in a relative sense)? Perhaps a higher level of strength would allow a runner to attain an even higher HR, and perhaps the current "max running HR" is not really a true max, much like a stronger cyclist could attain/sustain a higher cycling HR than a weaker one.
Have you seen the quads on those elite cyclists? There's undoubtedly a high level of muscle strength required for cycling at that level. But there's still a large element of aerobic activity involved.

But higher HR does not necessarily equate to better performance. In fact I think it's the opposite. As you get aerobically fitter, you can sustain faster pace, at the same or lower HR because your heart is becoming more efficient. Plus, your max HR can't really be changed that much, as that is dependant on the physical characteristics of your heart.

One of the main determinants of performance is VO2Max, your maximal oxygen uptake. This can be improved.

Muscle strength probably is a factor, but I think you get more gains from aerobic fitness improvements.
 

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Discussion Starter #6
Plus, your max HR can't really be changed that much, as that is dependant on the physical characteristics of your heart.

One of the main determinants of performance is VO2Max, your maximal oxygen uptake. This can be improved.

Muscle strength probably is a factor, but I think you get more gains from aerobic fitness improvements.
Yeah. What I meant though is the example of that guy only being able to get to 162 bpm on the bike, despite giving 100% balls to the walls effort. That's his max bike HR, not his true max HR. For him to be able to sustainably ride at those higher HRs would require him for be stronger muscularly (aerobic improvement also helps of course).

In the same way (though obviously not as much), perhaps one's max running HR is not really a true max either. In the same way that a cyclist needs to be strong to access those higher HRs (or else their legs will blow up before they get there or they'll blow up very quickly, i.e less than 2 mins), maybe a runner can access closer to their true max HR by improving their muscular strength.

That assumes there is a difference between max running HR and true max HR, which there might not be.
 

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Check this out: http://www.runworks.com/2014/02/running-vs-cycling-heart-rate/

Some of the main quotes:

"Most runners would probably agree that jogging at 60-70% of max heart rate is fairly easy: they can carry on a conversation without trouble, and maintain that heart rate for over an hour. But for some people, reaching the same heart rate while swimming or cycling may feel much more difficult, or even nearly impossible. Why?"

"Then I tried the HRM on some spin bike workouts. I cranked up the resistance, trying to bring my HR to the same zone as my easy runs, but the effort required felt extreme. It was like sprinting up a steep hill. My legs turned into blocks of stone, and I couldn’t keep going for more than a couple of minutes. Just for fun (this is fun?) I tried an all-out sprint with the bike at a high resistance setting, and found that I simply couldn’t push my HR beyond 162 on the bike, even as I was gasping for breath and sweating a river. After much experimentation, I finally settled on a resistance level that felt subjectively like a hard run, but still only raised my HR into the 125-130 range."

"What the heck is going on here? Why was the heart rate on the bike so different than the heart rate while running, when working at the same level of perceived effort? And what does the discrepancy say about the best way to combine training for running and cycling?

I did some research, and found that many other people have observed the same discrepancy between running and cycling heart rates, though mine was a bigger difference than most. This discussion mentions a 5% difference or ~10 beats per minute, this triathlon site refers to a 15 bpm difference in max heart rate, and this article talks about the discrepancy at length but doesn’t give any specific numbers. Intriguingly, though, it does mention that the discrepancy appears largest among runners with little cycling experience, and that pro triathletes with lots of cycling and running experience show little discrepancy in heart rate between the two activities.

Unfortunately, I never found any source that gave a really satisfactory answer for the discrepancy, but there are two general theories that come close to an answer when they’re combined. Theory #1 seems to be that fewer muscles are used while cycling vs running, so the demand for oxygen isn’t as high, and the heart doesn’t need to beat as fast. Theory #2 is that the leg muscles of a runner-turned-cyclist are comparatively weak, and it’s ultimately muscle power that limits cycling performance, not aerobic capacity. Taking a step back, these theories could almost be viewed as two sides of the same coin. In essence, they’re both saying that the ability of the heart to pump oxygenated blood to the leg muscles is not what determines the upper limit of cycling performance (and presumably perceived effort). More succinctly: cycling is a strength activity, not an aerobic activity."

"Unfortunately I find this answer vaguely unsettling. If I do a spin bike workout at the same level of perceived effort as my easy runs, and my HR during the workout is only 120, what part of my body am I actually strengthening? Will I get any meaningful aerobic benefit out of it? Or am I just training cycling-specific muscles, which isn’t a goal at all? I’m going to keep digging and see what more I can learn."

-----------------

This basically agrees with my experience. In summer I started out with zero running/cycling ability - call this my June cycling fitness. From then on I did 2 months of cycling and basically no running. Naturally my cycling ability improved a lot, but my running was still very poor. From then to now, I barely cycled and started running more, and my running ability has improved A LOT. But even inspite of that, my cycling ability has literally reverted back to my June cycling fitness(!!!???), even though back then I had zero cardio ability whatsoever, unlike now!

It's all very baffling and interesting at the same time. Hopefully you find it as useful as I did.
also your bodyweight is supported in cycling. your swim zones will prob be even lower for the same reasons

an elite cyclist will have higher HR zones in cycling rather than running. an elite runner higher in running.

I once tore my calf and couldn't run, yet could cycle perfectly well. different muscles ARE used.

yes, typically zones ARE different.

if you cycle in Z2 HR it is aerobic. If you run in Z2 HR ... it's aerobic. The zones MEAN the same thing (they facilitate the same bodily adaptations) but they are different for each sport usually.

if you do a LTHR test for each sport in a lab you would find out exactly how different they are. FWIW mine are 4bpm higher for running and i'm probably a better cyclist than runner.

VO2max is fine but does not take into account efficiency of technique. Look at LTHR it's more useful to look at that for most of us

I'm not sure where the confusion is?
 

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Not done both bike & run blood lactate thresh tests for a while.

Biggest issue for me was perceived exertion vs actual effort, from a run background I could assess my work levels very easily on the treadmill and knew when I was approaching the limit.
On the bike I would rate my exertion as relatively low, increasing slowly as the test went on and then find I was suddenly unable to turn maintain the required power whilst my perceived exertion was still way under lactate threshold.

But yes, obviously the zones are different... same as they would be for ironing or having sex (just two random examples off the top of my head there)
 

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Discussion Starter #9
I understand most of it now. I guess an extreme example would be trying to achieve max HR by doing bicep curls. Just not possible, or would require infinite perceived effort to get to it. :lol:

But why the discrepancy between, for example, 150 bpm jogging = zero noticeable breathing, whereas 150 bpm cycling = breathing a fair bit? Surely if your heart is beating at the same rate, it would correspond to you need to breathe the same amount? Or is how much you're breathing related more to VO2 max?
 

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I understand most of it now. I guess an extreme example would be trying to achieve max HR by doing bicep curls. Just not possible, or would require infinite perceived effort to get to it. :lol:

But why the discrepancy between, for example, 150 bpm jogging = zero noticeable breathing, whereas 150 bpm cycling = breathing a fair bit? Surely if your heart is beating at the same rate, it would correspond to you need to breathe the same amount? Or is how much you're breathing related more to VO2 max?
Interesting question. I wonder if it's due to the oxygen demands of the muscles and different types of muscle fibres being used?
 

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I understand most of it now. I guess an extreme example would be trying to achieve max HR by doing bicep curls. Just not possible, or would require infinite perceived effort to get to it. :lol:

But why the discrepancy between, for example, 150 bpm jogging = zero noticeable breathing, whereas 150 bpm cycling = breathing a fair bit? Surely if your heart is beating at the same rate, it would correspond to you need to breathe the same amount? Or is how much you're breathing related more to VO2 max?
your 150bpm at cycling reflects a harder effort FOR YOU as it is probably a higher %age of your LTHR or VO2 ie you are in a higher zone. If you were a bad swimmer and swimming at 150 you may well be in Z5 and nearing exhaustion (sy you may be an excellent swimmer, just giving an example, no offence intended)

re progressive feeling/perceived effort through HR Zones: if you train at your aerobic threshold then that kind of effort will become easier. If you do not train at your tempo type levels for your cycling then your performance will more readily 'crash' at those levels in cycling even if you train at tempo levels in running (but sure, not as much as someone who does no tempo training whatsoever)
 
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