Does an hour of Zone 2 effort cycling roughly equal an hour of Zone 2 effort running?

often hr zones are different due to different mechanics.

That's great! Would say that you're firmly in the minority if you're a runner who does some occasional biking. It's possible that you haven't really maxed out at either or are leaving something on the table in tests.

Like our "Triathlon Olympian" who posted after you, it takes time to develop leg strength on the bike. I would expect a triathlete to come closer than a pure runner who does some cross training. Maybe you've done a fair amount of biking. If you haven't and you really are able to push the bike maybe you should try a tri or duathlon.

Thanks for your input. What the two of you are saying makes sense.

Would you think the ARC Trainer or Stair Master are more equivalent to running? I personally find it much harder to get my HR up on the ARC than the Stair Master, although I keep the resistance low enough on the ARC to can keep my steps per minute up.

Regarding HR on the Arc, I find it depends on which version you are using - w/ arms or without. For example, Valby supposedly uses the Arc with arms and often for threshold workouts, which I find near impossible on a leg-only Arc. She also cranks the sh$t out of the incline.

The leg-only model really shines for light Zone 2. Some people try to up the cadence on Arc to 170-180 to mimic running, but many including myself find the Arc's sweet spot is around 140-150 SPM.

And yes, the Arc definitely feels much more specific to running than biking. Same muscles (although bit quad heavy) and similar motion.

No. Because to stay in zone 2 for cycling, you can’t get out of the saddle or put too much effort on your core. This happens after about 20 minutes while running in zone 2 though. Cycling in zone 2 builds more shoulder and calf/quad strength. Running in zone 2 hits the core more. I get about 5 hours of each a week and this has never changed for me

I haven't used either so can't really say but running is running imo. I've done some aqua jogging. I think anything that can mimic running mechanics is useful enough for cross training. Biking is good for building some endurance. It's useful in that sense. I tend to see runners push too hard trying to workout at the same heart rate. Idk how useful that is.

If he is an olympian, he does ITU. Chances are, he is NOT a good biker. Especially if he is from the U.S.

Several posts mention leg strength versus aerobic strength. Leg strength means different things for sprinting, distance running, and cycling. (Achilles, quads, calves, and hamstrings). Not only does just distance tuning add "mechanical strain on the body," it will unevenly develop these leg muscles which impacts the knees, and the strain gets progressively worse. By cross training, Valby has turned a weakness into a strength.

Zones are different per sport. Zone 2 for running and cycling won't be the same. Don't stress.

I would echo this. My friend is a GB Triathlete (no it's not Alex Yee) and he said when Cycling you'll only ever be able to get your HR up to 90% of your running HR - so typically when looking at cycling HR, add about 10% to compare it

Your friend doesn’t know what he’s talking about, or his cycling abilities are terrible compared to his running abilities. The idea that you should only be able to max your HR out at ~162 bpm cycling if you can max your HR out at 180 bpm running is so hilariously wrong.

My max heart rate is the same biking or running, always has been. Maybe the triathlete achieves higher heart rates in a triathlon because it's the last event of the race?

That might be correct for you, but in sport science, it is well known that HRmax is a little bit lower for cycling (5-10beats) compared to running. Therefore the same HR with running, is not exactly the same as with cycling, for the Joe average.

The heart rate is lower for cycling because the bike helps counteract gravity and you are not using the muscles in your upper body. Some distance runners are obviously more efficient with upper body movements than others.

it is also known in sport science that HR max is higher when cycling compared to running in well-trained cyclists

the issue is that the large majority of "sport science" is made up of volunteers from the local college campus that are neither runners or cyclists, in which case running is what is almost always is more natural for them

when all you do is ride your bike 25-30 hours a week for several years, your HRmax in the saddle is for sure going to be higher than when trying to run fast. cyclists tend towards having osteoporosis if they are all-in for many years, running literally hurts the bones so of course they can't push their body to the same limit, not to mention the tendons that become like steel cables and calves/quads/glutes/spinal-erectors only used to concentric contractions

so yeah, of course it's not always higher running

and for those of you parroting "the heart doesn't know", what do you say about the fact laying on a couch at sea-level while breathing an air mixture equivalent to 20,000' above your natural locale (via hypoxic generator) will increase your pulse 80-100bpm within minutes and over time it will steadily drift further up. totally reasonable to get a four hour session in at 150-160bpm while just laying on the couch, why even ride or run at that point?

ps, the high/lucidity after breathing air that hypoxic for about 60 minutes makes the $2500 for the generator seem like an absolute steal

This is a good and really interesting thread.

HOWEVER no one has cited and scientific studies to support their claims. Does anyone have any legit sources to support assertions here?

I'm glad you find it interesting. I think a lot of people do. The conversation has been productive. It's funny though, that my starter post currently has less than 20% up-votes vs. down posts. I think a lot of people think this is a total BS topic, and perhaps poo-poo certain aspects of the science of running as irrelevant. More of the "just run, baby, run" approach, and I get it. I think this is more just for curious minds, or those who are in related professions regarding the details about how the body actually functions physiologically in response to different stimuli.

The article I posted on pg. 1 has some references and I will check them out when I have some time. I'll post what I find. The author admits that there is a lot we still have to learn on this subject.

The heart is just a pump that responds to whatever stress is being applied.