Fluctuations in PE...

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This morning I did a typical 90 minute rather intense SST session on the trainer (Cylcleops Fluid), but in the last 30 minutes I noticed several *waves* of reduction in PE while power remained steady. I would generally ride these waves of increased power and reduced PE for about 3-5 minutes before fading back to a normal PE for the effort. Very strange burst of power... curious if anyone here has a metabolic explanation, or similar experiences to share...

Did they correspond with any changes in riding position, cadence/gearing or pedalling style (spinning vs. mashing, focused unweighting, etc.)? Small changes can help me feel better for a couple minutes when I'm hurting.

I don't remember whether you're using a powertap or some other method for determining power, but with your ability, one non-metabolic possibility is that the trainer fluid is simply heating up to the point that the resistance is dropping off. Then, after a short cooldown period it is returning to its previous resistance levels. That would really be for someone using trainer speed to estimate power, and not for someone using an actual powermeter.

This morning I did a typical 90 minute rather intense SST session on the trainer (Cylcleops Fluid), but in the last 30 minutes I noticed several *waves* of reduction in PE while power remained steady. I would generally ride these waves of increased power and reduced PE for about 3-5 minutes before fading back to a normal PE for the effort. Very strange burst of power... curious if anyone here has a metabolic explanation, or similar experiences to share...
don't take these questions/comments the wrong way!


What power meter are you using?
If not using a PT or SRM, could your rear tire be slipping slightly due to sweat and give you a slightly boosted power reading until it dries again?
Endorphins?

don't take these questions/comments the wrong way!


What power meter are you using?
If not using a PT or SRM, could your rear tire be slipping slightly due to sweat and give you a slightly boosted power reading until it dries again?
Endorphins?

1. No power meter at home where I was training this morning. Estimating effort based on mph. The trainer is a Cycleops fluid with a 3 month old resistance unit. PT is available at my health club though, and my numbers are consistent with Cycleop's published power estimates for various interval durations.

2. Don't think it was slipping I can usually hear and or feel a slip.

3. That's more along the lines as to what I was thinking... I've actually noticed this a couple of times after the first 60 mins or so. I think maybe one can reach a point as to where the lactic burn or at least the minds perception of it starts to subside after a given tolerance for a duration. Maybe?

Thanks again for your feedback!

Estimating effort based on mph. The trainer is a Cycleops fluid with a 3 month old resistance unit.
That sounds more like what I was alluding to in my response about thermal changes in the fluid unit. Here's another similar thread: http://www.cyclingforums.com/showthread.php?t=371034

That sounds more like what I was alluding to in my response about thermal changes in the fluid unit. Here's another similar thread: http://www.cyclingforums.com/showthread.php?t=371034
that's an informative thread. How did you find it? You mean the Search function is working again? :cool:

That sounds more like what I was alluding to in my response about thermal changes in the fluid unit. Here's another similar thread: http://www.cyclingforums.com/showthread.php?t=371034
You may be on to something, but the general consensus from the thread was that resistance had a tendency to increase at a steady rate for 30 mins, then leveling off... I'm actually experiencing the opposite - a periodic temporary decreases in PE / resistance after an hour or so. Based on feel alone it seems to be more of metabolic phenomenon, rather than issues with the trainer resistance. Just my gut... but I think there maybe some kind of muscle fatigue induced pain that actually subsides or at least periodically subsides when tolerating such pain for hours on a regular basis. Didn't LA have an usual tolerance for such pain, on top of his super human FTP?

No argument with the line of thinking above. IOW your trainer power curve may be varying over time. But I've felt PE rise and fall during long steady submaximal workouts. Doesn't happen at 95% or above, but I've done some hour to hour and a half efforts at ~85% where I first feel good after 8 minutes or so(not much warmup before these in training so the first easing of RPE isn't surprising) and then again at maybe half an hour to forty minutes and sometimes again after an hour or so. It might all be in my mind, but my power is rock steady according to both the CompuTrainer and my PT hub but sometimes it feels easier. It also seems to come in go in "waves" just like the OP mentioned.

I rode an hour and 20 minute effort at ~ 85% today at lunch on a gym erg. It went just as described above but at an hour I wondered if I'd make the extra 20 minutes. At an hour and ten I felt like I could go all day if I wanted. I don't know why, but I've definitely had this experience during longer low SST efforts. Too bad it's never happened during full on TT efforts...

-Dave

I felt the same thing yesterday. I was riding for an our and was doing around 90% when I spotted a fellow biker a few hundred meters ahead of me. I catched up with him and pulled him along. Somehow the RPE dropped while I maintained the same speed. No road undulations. Somehow, I think motivation have something to do with it.

bigbadwoulfe