Not convinced anyone for any certainty can say what the optimal recruitment pattern or contractile velocity is for all given individuals!

Folks have been chasing down this rabbit hole in power and speed sports for years and some of the worlds most eminent coaches and scientists working with athletes using tech to measure this stuff daily still cannot be specific what optimal F-V profiles should be.

I recall Inigo San Millan did some interesting work measuring lactate in the wind tunnel. This strikes me as a far better approach to quantifying efficiency.

i.e. ride at a fixed power.... test lactate. Change position for improved CdA, ride at same power..... retest lactate.

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David T-D
http://www.tilburydavis.com

I feel like most folks use a guess and check method with this in real life.

I started higher with stack and wider on the pads with my basic fit for TT some 3 years ago. Over time riding with it, I would do a virtual elevation aero test of a new stack/width and see what that was worth. Then ride it that way for a week or so and compare the power and heart rate of similar rides from the old fit.

If it wasn't an "oh my gosh" moment. I'd stick with it.

I got one of those "oh my gosh" moments when I accidentally used the wrong holes bolting my Aerocoach wing supports back on in 2020. I bolted them so they were so close my forearms were touching real good in the center.

I rode once indoors and once outdoors like that and went "nope nope nope". Power and RPE and comfort were shit. I didn't even bother testing the aero for it since it was a mistake in setup anyway.

I've been doing the same kind of thing, funnily enough! Being on the bendy/stretchy end of the spectrum though, I haven't found a position that really didn't agree with me though which is why I'm keen to find a way of quantifying the effect of aero positions on muscle recruitment. Must be a bit of a 'macro-absorber' as Phil Burt says.

It's all bollocks. You'll be best in the position you are adapted to.

Also it's bollocks because powerful positions are comfortable and aerodynamic, aerodynamic positions are powerful and comfortable. This entire cottage industry based on the opposite premise is bullshit.

Generally speaking, bike fitters that use "tools" are to be avoided.

E

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Why would you compare something that increases with by cube of something with something that can be adapted to and brought back to baseline? The slope of the metabolism line would have to be awfully steep or the margins between success and not success (ie. an Olympic Gold medal) extremely close to make this even worth discussing.

E

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

In and of that moment of aero testing / fitting one isn´t adapting to lactate production.

Lactate blood values are predicated on the amount of working muscle driving lactate production but also clearing or even reusing lactate as a fuel beyond muscles at rest.

So if an athlete has an aggressive position that is heavily quad dominant and they are supporting an excessive amount of body weight over the front of the bike then you´ll get very different lactate numbers to same athlete at same power in a different position using more posterior chain muscles actively and less upper body muscles to support weight.

Am not saying this is a panacea solution but if someone is parsing out factors at the level topic author clearly is/interested in then lactate is certainly a more valuable insight than sEMG data IMHO.

If one is pushing 300w and that remains unchanged whether there is more of less contraction in quads seems rather esoteric since the "system" as a whole is still producing 300w. You need to be measuring some other aspect of efficiency or cost to calibrate any of that change there so why not just measure that other aspect (HR / lactate / O2)?!

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David T-D
http://www.tilburydavis.com

When measuring Economy, Athletes are typically most economical in the position or movement pattern to which they are adapted.
If this is modified, their economy typically gets worse initially, but given an adaptation period their economy will improve.

Nothing, however, says that your economy will always be maximized following an adaptation period.

Spending a lot of time in a terrible position will still give you terrible economy.

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I talk a lot - Give it a listen: http://www.fasttalklabs.com/category/fast-talk
I also give Training Advice via http://www.ForeverEndurance.com

The above poster has eschewed traditional employment and is currently undertaking the ill-conceived task of launching his own hardgoods company. Statements are not made on behalf of nor reflective of anything in any manner... unless they're good, then they count.
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Consider the scale, and the cube of the velocity vs. a few more mmol of lactate. The whole premise is flawed. The best position is the best position, as long as we are on non-UCI limited but double triangle or beam tri bikes.

1. The best positions are also the most powerful and comfortable. No such thing as aggressive.

2. There’s no adaptation for drag... the cube doesn’t become the square after some time in the saddle.

I concede this might be relevant for someone going for the hour record, but flatly rejected that there’s any correlation between CdA and lactate until I see that data. In other words good for A/B testing or comparative positionology but not prescriptive.

E

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”