Power difference - indoor Vs outdoor - Page 3

I don't think the issue is climbing-just changing grade doesn't really change anything-but position. When climbing, it's more common to sit up, holding the tops of the bars or the hoods. On the flats, most people use the drops or the hoods with their elbows dropped. So you tend to have a much tighter hip/trunk angle when riding on the flat. With the slightly different joint angles, you probably need to put in some work in both positions.

Yeah that is a real wonder for me at the moment.

As I said earlier in this thread, as far as I'm concerned, I blame the higher perceived effort on trainer mostly on the fact that I usually ride at higher cadence indoor. Higher steady cadence. Their could be other factors as well. That's fascinating.

But that raises a question. Any benefit in doing 90min at 180watt on a trainer, with hr at 160 in avg, over 170 (90% of max HR) for the last 45min? While outdoor I can easily hold 240w (260np) for the same duration at lower hr?

I plan on spending time doing steady tempo on trainer during summer. The funny thing is that even though the power level falls into the lower range of the tempo zone, the hr falls in the lactate threshold zone somewhere in the middle of the workout.

Is there a reason you don't just pedal at a lower cadence?

I really doubt it, although it's an interesting question.

Is this because of time constraints or because you're trying to accomplish on the trainer what you can't do outside?

That is more a curiosity I'd say. My comfort zone is between 92-96. On the trainer I tempo at 98-100.


Well whoawhoa. You may be right. But on the other hand, the question is :
90min tempo on a trainer feels more difficult for those who experiment a lower avg power indoor. It seems to trigger higher breathing and heart rates. Does it worth more than doing the same workout outdoor at what appears to be lower metabolical costs?

Honnestly I treat both type of workout as being pretty different. I like both of them for different reasons, I approach them differently. So I don't aim at doing the same type of workout indoor and outdoor in summer time.

On the trainer, I enjoy recorded pro races and classical/jazz/rock music

As for the time variable. Well. If tempo is useful to work on improving cardiovascular functions, maybe by raising the cadence a bit in order to increase heart and breathing rates... I don't know. I am just giving it a try.

Don't shoot the messenger.

Here it is from the horse's mouth. http://www.cyclingforums.com/t-279842-15-1.html See replies #2 and #8 in particular. In addition to the inertial effects described therein, I'd include 1) motivation, 2) potential for overheating due to less airflow, and agree with Whoawhoa that 40w doesn't sound unreasonable for an *initial* difference in some individuals.

Sorry if that hurts your credibility as a coach, but just think of the power gains that will be seen (indoors) during a 2 week adaptation period. Talk about some success stories!

Damn, I looked everywhere for those posts. You've got a good search engine, frenchy.

I had the advantage of knowing who started that particular thread.

I noticed. Although, actually, I sometimes can't even find my own posts in previous threads. Alzheimer's?

No shooting intended

I have read and re read the various other posts but these clients were on an 8 week indoor course involving 2 indoor sessions per week (mostly 2x20) and so were "trained" indoor before buying their PT and then starting to ride outdoors and seeing this large and unexplained jump in threshold power (~40w) Added to that is that the indoor sessions were done at our studio in front of very large fans in an open environment and with a coach adding motivation.

I have had a good look at the various sessions and can tel you that HR was similar for indoor and out and the only variance was torque and a higher cadence indoors (~90 Vs ~70)

So I still do not have much of an explanation in so far as all I can offer is the mechanical difference between pedalling on an indoor trainer and outdoors.

Perhaps the cadence is influencing things to a degree.

That's a pretty drastic difference in cadence. Also, cadence affects HR pretty significantly, so I would expect a ride at ~90rpm to produce a much higher HR (+10-20 bpm) if the effort were similar. Is that rider able to see his HR during the ride? If so, maybe they are limiting their effort based on seeing a higher HR during the high cadence indoor rides.

Another thought: are you comparing AP to AP, or are they looking at NP for their outdoor rides? On rolling hills it's possible to generate an NP higher than the AP that could be done on a steady trainer interval. The difference is typically <5%, but for your 20min intervals it could be significant depending on how they ride.

I think that you have a good point re the cadence - will look at it.
The AP/NP differential for indoor and outdoor was very little as the outdoor efforts were on a smooth climb.

All I can say about the posts in this thread is, I agree with everyone and disagree with everyone.

Training on an indoor trainer can be as boring as hell and requires a cast iron will and highly focussed determination.
On the otherhand, this is not true.


Let me explain, if I get to my gym when it opens at 9am and start training in an empty gym, even with my iPod shuffle playing specially selected fast tunes, I find it difficult to generate any enthusiasm unless I know that RD is waiting to see the result of a particular session.

However, if I go to the gym at around 10 and there are delightful Japanese women on the trainers, concentration no longer becomes a problem, because I know they are sneaking a look at this profusely sweating foreigner's display with amazement at the Wattage and more particularly the calorie count rising to a figure in minutes that takes them 2 weeks to burn.
Vanity, egocentricity or call it what you like - it works because I daren't stop and disappoint them. (my self-delusion perhaps)

I see all the figures bandied about in these forums, but I can't recall seeing the adrenalin factor mentioned. It always reminds me of the woman whose son was working under his car when the Jack collapsed trapping him by the chest. She a fragile little thing, physically lifted the car off him! Sure this is an extreme case and she crippled her back, but nonetheless she did the seemingly impossible, not through regular weight training but sheer unadulterated adrenalin flow.

I think we are all capable of doing things we perhaps feel are not possible, given the right environment that is.

As soon as I quit my cadence comfort zone, power numbers drop in a significant way, and hr numbers go up.

Indoor, if I lower the cadence, then the power generated is closer than that generated outdoor. The remaining difference is probably a consequence of lower motivation.

One thing I have noticed, is that when spinning at higher cadence (98-104) indoor, I can't engage the glute muscles as much as I can when pedalling 92-96 rpm. At the end of an indoor high cadence ride, the doms are felt in the front quads, pretty close from the knees. Outdoors, at lower cadence, the doms are mainly located to where the glutes tie to the femoral bone.

I am still questionning about the use of spending time pedalling slightly over the cadence comfort zone though. I think that the 'old cycling school' used to advocate spending several thousands miles on the lower bracket doing just that. Somehow, I did mostly just that last winter. But didn't improve as much as I would have liked.

heat has something to do with it. this winter i did some experimentation and found that if, after my warm-up i opened a window or cracked a door close to my rollers (-10 or less celsius outside) my 2x 20 min power went up by about 20-25W, aveHR went way down.. and my power output was pretty close to what it was outside... 10-15W lower.. i was really amazed at the difference. i believe a huge portion of the difference is from heat.. your HR just skyrockets unless you keep the room temp down and have a good fan that cover legs and torso.

boredom and motivation is also a factor.. but cooling the room and seeing your power number get within a reasonable margin of your outdoor numbers does a lot to get your motivation up... cooling, cooling, cooling.

Thanks - that's a real big difference in power. We do usually use big fans from the front but that is not the same as outside temperatures.