Indoor Vs Outdoor FTP

True. I guess that heart and lungs do the same work and get the same training effect but what about locally? Tearing muscle fibers to be rebuild and get stronger, mitochondria and lactate clearance and more blood vessels and so on

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I would think that is a huge benefit. Dealing with heat (improving that) is a big part of performance.

I first wanted to say it would be the same training effect if the effort was the same, regardless of power, but zooming back, I think it would simply be different. Lower power but same effort, so assuming a lot of the extra energy is going into thermo regulation, means you will be training to produce more power than your same self that has a lower thermo regulation ability. Just speculating, not based on any science.

That’s exactly the question(s) I have and already tried to pose them here on the forums. Somehow it didn’t catches on. And also in the podcast all I hear in this direction just focuses on the aspect in the likes of “just get enough ventilators in front of you and overall get used to training inside and your wattage difference between indoors and outdoors will get lower and lower” followed by anecdotal reports that for Jonathan indoor wattage and outdoor wattage is the same.

Really doesn’t help and it would really be worthwhile to pursue this questions deeper.

And it’s not only the heat. It’s another firing cyclus of your leg muscles in each normal pedaling repetion between the difference indoor even with the biggest of flywheels and outdoor. And all the micro and macro core muscle and supportive muscle stimulus. Obviously I’m not mentioning riding technique here which, while also very valuable may be really not related to physiological training gains we are talking here.

So what leaves us this? I think it’s like with all other things. The dose makes the poison. And variety is helpful.

So I think having some indoor rides can be a helpful stimulus with the precise following of intervals and even for longer stuff (2 to 4 hours - yes, I do them) the relentless sustained pedalling. Giving you a very good bang for the buck.

But - even with the cardiovascualar system running at high pace and extra load because of the heat I sense that after prolonged periods of indoor riding I have to getting the actual motor units, i.e. the muscles, used to outside riding and really producing power again.

So my own anecdotal take and the best I can compile from all the info I scrapped from books, websites, other resources and also the TR podcast in the last years is, that while you may get a very top notch training of your cardiovascular system - that’s not the whole package. You leave something on the table when not training outdoors. That might be mitochondria production in the muscles or neural adaption or whatever. Those watts invested in cooling and not in straining your muscles certainly must hurt in any way. And I’d really like to learn if there are some studies about this.

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Well in theory you could hyperventilate… would that stimulate muscle adaption or better blood vessel distribution and mitochondria generation?

Would having a high heart rate alone, because you are nervous before a (mathematical) test or in the hours leading into a race stimulate any of the above?

I wonder whether or not there is a different affect here.

If your RPE and HR are the same but a bigger proportion of the effort produced by that RPE and HR is diverted to heat management then it stands to reason the amount of energy left over to be produced as Watts into the pedals would be less?

Hence to hold the same wattage (as measured by the indoor trainer) when in a much hotter room, requires a higher HR and RPE.

Just a speculation - I’m no biologist but I can’t imagine the body can regulate more heat without either upping the HR and RPE or keeping both the same but reducing power delivered by your legs?

Edit: so what I am postulating is that if you train in a materially hotter room, and the RPE and HR remain the same then the training effect is actually less (on your legs) because you are actually pushing less power for the given HR and RPE but the ‘overall’ CV effect may be similar due to the similar level of strain on your heart and lungs?

Surely something has to give somewhere? Or is this what is already being said and I’m just being thick? :laughing:

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I’ve been involved in this thread since it’s inception and nobody has come up with a proven reason. I have the same problem. Lower power and HR indoors and increased RPE. Have tried so many things, none solving the problem. Main reason why I prefer to do workouts outside. My latest opinion is that I’m not using my upper body indoors, so HR doesn’t need to be as high and the upper body does contribute to power, so power indoors is lower. I thought it was temperature related at one time, but I’ve tested that may times and it didn’t make a difference for me.

I even purchased an Inside Ride to test the upper body theory. But the movement on that wasn’t what I expected and actually made RPE worse. Actually looking to sell it. (At no fault of Inside Ride)

So keep asking the questions. I’m paying attention closely for any other ideas.

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sorry this doesn’t directly help… here is a recent study of a 20-minute time trial and indoor/outdoor power output was about the same: An Analysis of Variability in Power Output During Indoor and Outdoor Cycling Time Trials in: International Journal of Sports Physiology and Performance Volume 14 Issue 9 (2019) and full version here: An analysis of variability in power output during indoor and outdoor cycling time trials - ePrints - Newcastle University

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This feels like the type of study that you could find another study with different power between inside and outside. However this study had basically the same power inside and outside.

The conclusions were:

  • more power variability outdoors (big surprise LOL)
  • indoor testing protocols should be designed to reflect the external demands of cycling outdoors

FWIW one of the reasons I prefer TR’s PowerMatch with big chainring on Kickr 2017 direct drive is that my indoor ride’s power fluctuations are more realistic versus outside. That said inside power fluctuations are smoother / less variable than outdoors. But its better than the downright unnaturally smooth power fluctuations of the little chainring. My opinion of course.

I also think Joe Friel’s take on indoor training pedal economy is interesting. His point in 2nd paragraph about lack of swaying side to side is well addressed by Inside Ride. And his point about reducing the “dead spot” on direct drive trainer means using the big chainring and a heavy flywheel, along with more active pedaling to avoid “kick and release” across the top of pedal stroke.

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That’s interesting. I think I made this point earlier, but I’ll make it again.
I use a Kinetic Rock N Roll trainer. My bike sways side to side as much as it needs to. I have only ever used this trainer (new to cycling).
My indoor and outdoor power is about the same, but a slight tip to indoor power being HIGHER which I think is because you have less peripheral distractions indoors; you can just focus on hitting the power and don’t need to be concerned with avoiding potholes, oncoming cars etc etc.
Perhaps it is the fact my bike rocks side to side, very similar to outside? :thinking:

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My point. :wink:

I’ve not had major differences inside v outside. But do almost all indoor work on emotion rollers. It’s easier to do the longer VO2max intervals outside but I’m convinced that is mostly mental. $0.02

All I know is, if I am fatigued and unsure if I will be able to complete a workout I take it outside and find I can complete it no dramas. RPE is absolutely lower outside and I can push higher average watts for the interval as a result. So I wonder if I shouldn’t do all my workouts outside. Higher wattage has to mean higher return for the effort.

The big upside is when I come to race, I feel like I am flying and smash big numbers! Still haven’t found an answer to that question.

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Is there any way how to tweak outside workouts to use my outside FTP? On TR, garmin connect or even on the Garmin Edge 820?

Someone mentioned to click on “little pen”…

This question has baffled me for awhile, and I wish there were some real scientific studies to see what the real effect of a discrepancy is. I definitely have a pretty big difference inside vs outside…though I don’t know the exact number because haven’t tested with the same bike/power meter within a short period of time.

I do wonder though that if you have a significantly lower inside FTP, are you actually stressing your body enough to create ideal adaptation if the majority of your riding inside. If you’re capable of pushing 300 watts for an hour outside, and 250 watts inside…and then you spend the majority of your time only pushing your muscles relative to a 250 watt inside FTP, even if the RPE/HR is hard, are you truly pushing yourself and making the gains you should be? OR…are you just getting better at riding inside. Why is it different from someone who can squat 300lbs only squatting 250lbs all the time, or basing their workouts off a lower 1 rep max? Or someone who can run a 5 minute mile basing all their workouts off a 6min mile max. Or maybe it doesn’t matter, since the biggest factor is time on bike and accumulating some amount of stress.

It’d be cool if some study tracked cyclists over a period of 6 months or something, where inside/outside FTP was calculated for both…then half the group did exclusively inside workouts, half did exclusively outside workouts of exactly the same structure…and then inside/outside FTP tests were done at the end. If the group that road exclusively inside raised their inside FTP’s by 5%, did that translate directly to a 5% outside FTP increase? Did the group that trained outside, but had a big inside/outside FTP differential raise their FTP’s by more outside as compared to the group that road inside and had big inside/outside differentials. Obviously it translates, or we all wouldn’t be getting faster and guys like lionel sanders wouldn’t exist…but the differential just begs the question as to if we’re selling ourselves short by training inside.

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I wish to know why too. I’ve tried so many things to try and close that gap. Whether I am getting the expected adaptations is my biggest concern too because my difference is so big that for a threshold interval indoors, I’m riding at my outdoors zone 3. So I end up doing all my intervals outdoors.

Interesting discussion. I’m stronger indoors vs outdoors. For me, that makes sense, as indoors, all your focus goes on pushing the pedals. Whereas outside, you have to balance the bike, scan for obstacles, make decisions based on other road users etcetera.

You lot with a lower indoor FTP are weird :smile:

All I can add is I use a Rock n Roll indoor trainer. Maybe that lateral movement is crucial to performing like outside :man_shrugging:

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Love your squatting analogy. If the squat bar was somehow sticky against something, like your were dragging it against the rack without knowing it (weight reads lower but overall stimulus is there), my guess is that compares to the trainer inertia issue, and is a big part of why the discrepancies vary so widely (different trainers between everyone).

Personally, same bike and power meter, I’m 30W lower indoors, regardless of temperature, intensity, position. It’s very consistent. And feels very inertia-related (old CycleOps Magneto).

My TR FTP is set for indoor wattages, and my TrainingPeaks FTP is simply always 30W higher. When I upload TR workouts to TP, I copy over the TR TSS; when I ride outside, TP gives the correct TSS. Not to favor tracking on one vs the other but consolidating them has helped keep things straight.

Definitely feel like the respective intensities do their job even if the number is different. The indoor workload is SO much higher even with a lower power meter reading, but for sure some time outdoors each week helps ease any adjustment period.

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Strangely since I’ve been outside for the past 3-4 weeks, I can’t seem to push the same power as indoors. I’m not sure if it’s due to generally riding longer or just not having the flat consistent roads or steady longer climbs in my area.

I’m wondering if I just got good at pushing trainer watts!

Power is +30 - 35W [PowerTap] outdoors over indoors. FTP would naturally somewhat follow that rule.

On TreaningPeaks you can set different FTP for MTB and Cycling so i use MTB profile for indoor and Cycling for outdoor Rides. In TR I set my outside FTP and then I just reduce workout with percentage!

But I also wandering if I’m doing enough inside… Because I only ride indoors to train for outdoors…

I’m also affected by a high discrepancy between indoor and outdoor FTP. I use the same bike and the same PM. Regardless of the reasons, I would love to see an option to change the FTP for outdoor training, before pushing to the Garmin. Otherwise I painfully recreate the same workout in Garmin or Training Peaks before heading out. Or just don’t bother and go ride my bike :slight_smile:

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