It’s been well established that gearing on the kickr makes a noticeable difference.
But what about my Neo 2? Does gearing also affect the power output on the tacx?
Do you think you could put a value on how much harder it is on the dumb trainer? Unlike some people using a Rock ‘n’ Roll 2, I don’t like mine very much. It feels inconsistent especially at threshold and above. I should try a trainer tire and a bigger fly wheel but I’m not convinced it’s going to get me there, I think it’s the fluid system they use. I’m pretty interested in resistance based rollers and wonder if that could help me bridge the gap (it’s a big one typically) of my outdoor v. indoor FTP.
One study of 20 cyclists proves this?
All,
The way I’m currently thinking about FTP is that if I have a large block of indoor work on the calendar, I test inside. If I have a large block of outdoor work, I test outside. That makes the most sense to me instead of being so focused on the different numbers, this mindset should allow me to set up proper training zones. Am I missing anything?
Last, I understand why TR pushes indoor work so much, but isn’t there a TON of value working outdoors when it’s available? To the end that there’s even more value in outdoor workouts than indoors especially when we start to near A races? Skills, dealing with outdoor factors, riding in groups… I get that it’s much easier to become distracted outside but it’s more satisfying to me to get the work done outside. probably because I’m one that can hit much bigger numbers outside. Also, hills help me a lot. I know there’s a lot to that last sentence.
3 Likes
Hesitate to make a guess as it would be just a guess. Also considering the sensation might be mental and not physical.
For me, I think it’s not being looked into a single position on the rollers vs fixed trainer. Would be fun to compare fixed trainer on a rocker plate vs the eMotion rollers. But too lazy to build a rocker just for the experiment!!
1 Like
Thats how I see it, but it is not alway possible or preferred even though we have good roads and blessed with ‘ride outside all year’ weather. For outside workouts I prefer doing aerobic base, tempo, sweet spot, and max effort sprinting. Inside work is largely vo2 and sweet spot, except when the days get short.
1 Like
I wonder - could the air quality indoors contribute to the discrepancy between indoor and outdoor perceived exertion and @mpe’s lactate levels?
According to an air company’s blog post, which is hardly a rigorous study, we deplete oxygen indoors at a negligible rate, but CO2 does seem to increase an appreciable amount. They claim that in their tests in their office, the CO2 levels had reached a level where people might feel “drowsy and may even perform worse on cognitive tests.”
Is it possible that the level of CO2 build up indoors affects your RPE? And if so, to what degree? I could imagine this having some effect for those who use small spaces with low air flow.
But I feel I perform as good if not better indoors. Others feel they perform better indoors 
Interesting idea. Hoping to hear more on this as I’m one that has a way lower ftp indoors. It’s also harder to get the HR as high indoors as well.
This sounds like a good point indeed. Would be nice to compare performances and lactates in a larger room with forced ventilation and smaller gravitationally ventilated room (as my pain cave).
1 Like
I will do similar test with also the trainer part outside next summer 
1 Like
I only use my small chain ring indoors (KK road machine) to minimize the noise vs mainly my big chainring outdoors. Think this is why my indoor FTP is a bit lower. I actually don’t mind; get to use different cadences that way.
''Think this is why my indoor FTP is a bit lower ‘’ → is my theory correct?
No, I wouldn’t think so.
1.) that’s a blog post with a very clear agenda - to find arguments left right and center to strengthen their products (fair game).
2.) It does in no way try to relate to physiological studies.
3.) anectdotical: as the blog entry states, normal rooms let outside air in. You wouldn’t tape off your room before going onto the trainer. For it’s the opposite, in fact: I open my window (more precise, my balcony door) on slant to let my room cool off a bit more. Doesn’t solve the simple fact that my indoor ftp is lower and rpe is higher.
1 Like
Very interesting topic that I have given a lot of thoughts into the last year.
What I am wondering is the difference in training effect from two seamingly equal efforts inside and out but with a huge difference in watts.
Lets say that you do an indoor and outdoor ride with 4x10min of sweet spot work. Inside you produce 240 watts for each interval and with an RPE of 7 and HR of 170. Outside you produce 270 watts and and RPE of 7 and HR of 170.
Which one of these would produce the best results in training effect if your goal is to be faster on the bike?
And another question. Does your body produce 270 watts in both scenarios? And if so, does 30 watts go into cooling instead of pushing power into the “wheel” inside? Or does the body actually produce 30 watts less inside?
If the power produced is the same but 30 of them end up as cooling instead of movement, the strain is the same but the training effect on the mucels in the leg that produces movement should be less? And that would mean that the training effect with a goal to be faster on the bike is lower inside than out with the same strain both mentally and physiologically.
I mean, you dont get faster on a bike from training yourself to endura hot saunas for a long time, right?
1 Like
I really do belive that the heat is a huge factor. The big question here is if the training affect is the same.
If you do two efforts with a big difference in power output that strains the body at the same lever (RPE and HR) the training effect should be lower with a lower power because you put you effort into other stuff than producing power and train other useless stuff like heat handling. (only guesses here and no facts)
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
1 Like
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.
2 Likes
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? 
1 Like
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.
2 Likes
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
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.
2 Likes