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  1. #1
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    Question on Power and Indoor Trainers

    1 - is power output lower for a given RPE on an indoor trainer than outdoors?
    2 - how much?

    Note - I've tried searching the various forums (BF, CF, googlewattage) on this topic and found lots of speculation and physics discussion that I dont care to understand about why this might be, but I cant find a simple statement that says -yes or no this is true/false, and how much.

  2. #2
    pan y agua merlinextraligh's Avatar
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    I'm assuming RPE means rate of perceived exertion.

    If that's the case, I think the results would vary by individual. For me personally, I find it easier to keep the watts up on the road than on the trainer.

    Steady States for example, seem much harder to me on the trainer than on the road.

    Some people find it easier on the trainer due to the elimination of distractions.

    The individual variability is the reason I don't think you'll find a simple yes/no answer.

  3. #3
    base training heretic Squint's Avatar
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    1. For many but not all people, yes.
    2. There are no hard and fast guidelines. Additionally, it may change as you adapt to riding indoors.

  4. #4
    Ninja don't wear flipflop king-tony's Avatar
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    It would most likely depend on environmental conditions. For example if you did not use a fan then you would certainly heat up faster and experience higher cardiac drift as the session wore on. However, if it is 110 degrees outside and 50 indoors.... you get the point. In my experience, it is much more difficult to get my heartrate up on a trainer than outdoors, but I can't tell the difference after that. 200 watts feels the same to me indoors or out.

  5. #5
    Senior Member Duke of Kent's Avatar
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    A lot, lot lower indoors than outdoors.

    I'll adapt a bit as the winter goes on, but right now I'm probably 30-40w shy of what I can do outdoors for 20min.

    And this is in a cold, unheated garage. I just cook.
    "If a non personal post makes you feel as if you've been attacked, maybe the problem IS you."

  6. #6
    Eternal Cat3 Rookie branman1986's Avatar
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    I dunno what the exact difference is for me, but I'm like Duke and the rest. I'm way lower indoors on the trainer vs outdoors.

  7. #7
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    I think lack of motivation and not being able to swing the bike left and right (with the exception of the new kurt kinetic rock and road trainer) can account for the lost power output.

    The most power I've ever put on a trainer is around 1000w, though on the road I can hit 1400w. Mainly because I cannot use my arms to pull the bike.

    But seated efforts, I'm pretty much on par powerwise, maybe a little less.

  8. #8
    not a climber
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    I mis-placed my HR monitor strap, but did my usual 40 minute spin on the rollers anyway. Without the HR monitor, I used RPE, and the usual combination of gearing and cadence. What is the physiological significance of the point at which sweat begins to bead up and run down your face and arms?

    Probably it's different for every cyclist, and depends on temperature, relative humidity, moving air, etc. But is it something simple like, the point at which your work is producing heat faster than the amibient conditions are taking it away, and your body temperature has risen (you've accumulated heat), so your cooling system emits the water to get evaporative cooling, but it's only noticeable if the humidity is high enough, so the rate of evaporation is low. Ok, nevermind, perhaps it's not simple.

    Is it coincidental to anything? I don't think it is the mark of being "warmed up". In Atlanta in summer you can barely walk across a parking lot without breaking a sweat. I haven't there, but I imagine a 50F day in (dry) Phoenix you can do mutiple intervals and never see sweat -- it's evaporating as fast as you're making it.

  9. #9
    Oh The Huge Manatee Lithuania's Avatar
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    i actually put out some of my best wattage while on the trainer. Probably because I had all that extra practice during the summer this season.

  10. #10
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    i am with the previous post. i can generate about 1275 watts on a sprint (via PT reading) indoors on the trainer, but cannot approach that outdoors at this time. i also do a lot of training indoors and am likely becoming an expert trainer rider. if anyone knows of a race out there where all participants sit on the starting line with their bikes locked in their trainer, please let me know!

  11. #11
    this portrait of karma transplant's Avatar
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    Quote Originally Posted by VARacer View Post
    i am with the previous post. i can generate about 1275 watts on a sprint (via PT reading) indoors on the trainer, but cannot approach that outdoors at this time. i also do a lot of training indoors and am likely becoming an expert trainer rider. if anyone knows of a race out there where all participants sit on the starting line with their bikes locked in their trainer, please let me know!
    these people just put on an indoor time trial using computrainers: http://www.abdcycling.com/

  12. #12
    Realist Greg180's Avatar
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    Quote Originally Posted by transplant View Post
    these people just put on an indoor time trial using computrainers: http://www.abdcycling.com/

    Incline Training does the same event on their Compu Trainers and they also rank all of the riders that utilize the facility. http://incline-training.com/documents/10KTTRank.htm

    I'm hooked on the computrainer so much so I convinced Incline to advertise their Compu Trainer sales on Bike Forums. For me nothing beats it. I was using a power meter and a fluid trainer but the Compu Trainer takes the dead spots out of the pedal stroke and forces you to apply power consistently improving your pedal stroke. For me it was an eye opener. This quality training reduces total training time which is why I am sold on it.

  13. #13
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    After a bunch of riding indoors and out in the last month or so, I have to say that I can put out higher max and avg power while riding outside. I suffer from needing to get out of the saddle to apply significant power. Indoors I max out at perhaps 800, maybe 1000 watts. Outside I go another 500 more.

    However, properly motivated, I can do a pretty hard indoor ride. Motivated = atomic balm heat rub, some kind of caffeination (Gu, gel, coffee or other drink), big fan or two, bike vid, and very loud music (usually headphones). I can come close to replicating outdoor averages over 2-3 hours during a motivated trainer ride.

    cdr

  14. #14
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    I find it hard to even hit LTHR much less FTP indoors. My legs tire out before my heart does. For max wattage I can only hit around 900 indoors where outside my max for the year (past week since ive had the PT) is 1297.
    Please remember that all statements unless quoted, are strictly my opinion of what happened. That there are as many opinions as there are spectators attending. I just choose to publish mine on this forum. And would NEVER intend to purposely hurt or discredit any other cyclist.... With that said... HTFU!

  15. #15
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    The lack of momentum on a trainer (or something else) makes my legs hurt so much more at lower heart rates. Unless I let myself get really hot (no fans) in which case I can get the HR right up there...but I suspect I've got an FTP of about 50 watts in that situation.
    Patience - Consistency - Motivation

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  16. #16
    Burning Matches. ElJamoquio's Avatar
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    Personally I think I drop about 40 watts indoors. Speculation might include motivation, heat, concentration... but for whatever reason it doesn't happen.
    Reacting is mind candy; it requires no thought. Thinking is tedious.

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  17. #17
    部門ニ/自転車オタク NomadVW's Avatar
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    My 4 minute intervals are usually done around 420. I have a very hard time getting 380-400 repeatable indoor. It sucks. Fortunately I just don't do the indoor thing.
    Envision, Energize, Enable

  18. #18
    Senior Member Duke of Kent's Avatar
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    I already posted in this topic, but a bit of an update.

    Generally speaking, I do "hard"-er days a week, year round. And generally speaking, I do a 20min interval and then whatever I can throw down after that, be it a hard group ride, 10/5/1min intervals, whatever. So I think I know my body pretty well.

    Wednesday night, as I'm prone to do in the winter time, I did my 310-315w go-till-you-blow session on my rollers. Generally, I can last about 12-15 minutes, and that's a struggle. I should probably lower my goal wattage, but what fun is that. I'm just trying to keep the legs awake, not do any REAL work right now.


    About an hour ago, I got done with my interval session. But this time, I did it outside in the balmy 40*F weather. In shorts. All things given, probably not ideal conditions either, but a bit better than the rollers. I cruised for 18ish minutes, stopping a lap short because I thought my rear tire was going flat. 327w was the average for the duration. Fairly confident that I'd continue the soul crushing for another 1:3X if necessary.

    So, outdoors, over a longer time period, and still in less than ideal conditions, I was putting out 15+w more, on a glorified crit course.
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  19. #19
    WPI roy5000x2's Avatar
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    I just started doing indoor training at a performance center near my house. They set a bunch of us up on trainers, hook us up to a computer, calibrate us for near-real life settings, then let us loose. It was a hell of a lot more fun than riding rollers, since they simulated hill climbs and such. Four other guys and I did a 10 mile time trial. I finished in first with a average speed of 21.4mph and an average wattage of 332. I have no idea what the average HR was, but it was probably up there.
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