Anyone tried using their PT to play with position? If so, was it worthwhile?
And, whether you have tried this or not, any ideas on how to carry this out?
What to do/not to do, what will yield more useable or valid info., etc.
First question I suppose is - Is it even worthwhile?
As simple as get on trainer, warmup, pick a designated HR and note watts, move seat/bars and repeat?
How to chose an HR? Use more than one?
Any particular order to adjustments? yada yada
My PT will arrive shortly. Yeah, i’m a bit anxious.
C.
Don’t push me cuz I’m close to the edge.
To add to Rip’s comment – yes, unless something is wildly wrong, you can’t “tweak position” by using real-time power data. The changes you are looking for are small enough to fall within the variance between any two workouts anyway. That is, it’s in the noise.
Bike position tweaks are best done over time, with an evolutionary process. If you have a hunch that a given change is good, then make the change and ride your bike for at least 3 weeks that way. Under highly controlled conditions, almost any change to an experienced cyclist’s position results in a drop in power. The reason is that they are adapted to their current position. The only way to know if a new position is better is to take the time to adapt to it. And that takes 3-6 weeks (as does almost any training adaptation). Make small changes and go out and ride. Listen to your body very carefully. Keep a training log of power, time, HR, PE, comfort, recovery, etc.
For the same reasons, Computrainer bike fits are pointless.
You’ll love training with power! Good luck with the PT. Get the CyclingPeaks Software if you can spare some extra dough. www.cyclingpeakssoftware.com
I would disagree with the previous posters and say that it can be done, but it’s very difficult.
My steps are, find a very flat course of decent length and preferably lots of foliage to shield wind. I have a 10 mi club time trial course that works well.
Basically, you run the course and plug in all the data into analyticcycling.com (my course is a flat square loop that plugs in easy). I get weather data from wunderground.com and use an online calculator to find air density from temp, humidity, pressure, etc. (this is very important as it varies a lot from day to day). It doesn’t matter if you’re putting out different power on different days (as long as it’s consistent through a single measurement, my ave P is usually within a watt or two of norm P), as you can plug that in.
I use a default cd of .7 as per advice on the topica wattage list, and tweak frontal A until I reach my actual time. I’ve been seeing a frontal area of ~.39 m2 with a fair amount of repeatability (including at different average wattages as well).
The bad news is ANY wind can throw it off more than your positional changes. That is to say, any positional changes I’ve made have amounted to a couple percent change in drag, which is usually less than the variance from wind. They do seem to correlate with frontal area measurements via digital camera however. It’s difficult to find dead calm days where I live, but they do happen. I think with enough test repeats, you could get somewhere. Worst case, the data has still been instructional for training.
Thanks for the thoughts y’all. Make for a short thread. 
My gut has long been questioning the notion of gaining speed/power in an hr or two spent with a fit/position expert, or many hrs on my own with my PT. I’d love to believe it, but that don’t make it so.
A fun project in theory (hence my question), but for me, not worth the kind of time investment andy describes. More a recipe for frustration and a payoff I’d always question (as in, if I’m in charge of all those machinations, the data will likely be flawed).
C.
I hear ya. But if I’ve got a pretty good position going in, I think it’d be tough to move me around slightly and suddenly see a true boost in watts in one session.
But, like I said, I’d like it to be true, so I welcome being convinced.
I may try a local fitter in a few weeks, just for an assessment of my self selected position, and if so I’ll do it with the PT on board.
I would agree that a fitter would probably be a better (or at least much less time-consuming) investment.
I’ve just been experimenting for fun (along with measuring my weekly 10mi critical power) and to strive to achieve the frontal area of some of the guys on the wattage list. There are folks on there that say they run 40 km/hr at about 215 watts (and have the tt times to back it up). I would kill for that. My best 40 km has been well over 215 watts but still well over 1:00:00 ;-(. You can definitely hurt your power if you get too uncomfortable, but that is a whole other thread…