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marekmixa

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 #1 

anyone tried to optimize pedaling technique with moxy? Im able to reach almost 0% smo2 on vastus medialis, 10% on vastus lateralis and rectus femoris. still havent data for gluteus...

Idea is that>
move saddle higher, backwards and hopefully VM would be (on the same power otuput) little higher and others lower. And there will be space for higher power 😉

also I can use one moxy as checking point. Placed on non working muscle I can know when body needs oxigen from there. I can use some ramp test and checking just time - this is solution for problem that I cant measure all muscles on leg. 


I have only two moxy devices, it needs lot of data and experiments.

anyone?

sebo2000

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 #2 

I had pretty good results with single Moxy, two should be more than enough.

 

If you have Kicker or any erg trainer that can be controlled via power meter it is quite easy to do.

 

Initially I would avoid doing ramps. Yes they show smo2 at different levels etc, but for initial assessment it will just make you tired and could give you inconsistent results if the raps ae to hard. I would leave that at the end if you need to make final tweaks.

 

Just as an example I was doing 2x5min intervals at kickr set to 70% of FTP. (or simply intensity that will not make you tired on the last interval)

15-20min warmup.

 

1. Moxy on VL 2x5min, 1min rest for moxy change.

2. Switch to RF and another 2x5min at the same load,

3. Switch Moxy to BF and another 2x5min.

4. Continue with all other muscles you want to find out on the same day)

 

(with 2 sensors you can measure 2 muscles at the same time, it will speed up the whole process)

 

I was doing the same protocol on 2-3 different days to have comparison.

 

I could easily desaturate VL to 0%, my VM was really weak, and my hamstrings were even weaker. I had problems with sprints after long final race accelerations, I was simply getting dropped at the very end, and not because I was weak, but because I was using just one muscle.

 

Now I use hamstrings for accelerations and surges, also use my VM way more.

I can’t desaturate my VL to 0% anymore, difference between muscles is not that dramatic.

I remember my first “hamstring” engaging intervals was doing them at 45-50% of my FTP but they felt like VO2max sessions.

Andrea

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 #3 
Great idea but I think is not the way to go to optimise your position.


sebo2000

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 #4 
not position but pedaling technique...
marekmixa

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 #5 
what exactly "exercises" you mean?

last week we made a big testing - all riders of our team, two moxy devices, wattmeters and lot more 😃  

Im still analyzing data, and preparing it for undestadable form. 

One of test was track time trial (3km - juniors) with moxy on rectus and hamstring. Few riders (imho) almost never used hamstring and oveloaded rectus during standig start. After last few days additional measurement I think thats mainly muscle coordination issue.

So Im asking about these exercises 😉  I have a few ideas - not directly focus on hamstring in gym but more complex exercise where body have options - use hamstring or gluteus or back...  and than try to use hamstring.  

Ideas?

sebo2000

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 #6 

I can just comment on my personal case. Recommending any exercises might not be the best approach, since each situation and body is quite different, our habits, training hours, terrain we train in are all different. Your tests are good and will surly give you great picture in to your athletes.

 

After analyzing my muscle engagement at different power (engagement was changing once the power was high, especially above FTP) I determined I do not use hamstrings enough. I was primarily using VL while seating in the saddle, going out of saddle was killing me in 10-15 seconds. I could follow any initial acceleration even by way stronger guys, but then I could never hold their wheel for long, also was always dropped in final sprint.

 

I started research how to engage\train hamstrings, I quickly realized I will first need to work on my vastus medialis to be able to fully utilize my hamstrings. I was training on the bike and off the bike, I had to drop my power really low initially to be able to complete intervals with good form. I had back problems when working on hamstrings at the same power, hence dropping power to really low numbers, my hamstrings were totally untrained.

 

What type intervals you ask? Attach moxy on muscle in question and experiment, changing pedaling technique, cadence, position etc. I was aiming to desaturate my hamstrings as hamstring engagement indicator.

 

I train sprints mainly on very low power (I know it might sound counter intuitive), in the past I use to only push on pedals, I found that pulling leg at the same time makes huge difference in my case. Initially the power didn’t really increase, but I could hit second sprint at the same power just few seconds later for the same length. Again this is road bike not fixed tack bike.

Andrea

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 #7 

hi Sebo2000,
yes, I misunderstand the "pedalling technique" with "position" (because I read some post also on that).
Pedalling technique is a very interesting topics and I did my master thesis on it, measuring pedal force efficiency from force component on the crank in relation with power, cadence, saddle height (+/- 1cm from riders position) and level (sedentary/amateur/pro)... results was showing there were no relationships with saddle height with pedal force efficiency. Cadence was influencing it (> cadence < PFE), power too (> power > PEF) and level (PEF pro > PEF amateur > PEF sedentary)....
There's also an interested published study that compare pedal force efficiency and pedal cost: comparing "hammering", "circling pedalling" and "normal" or self pedalling
). When you modify your pedalling techniques you influence a lot your cost. "Standard" or self pedalling is the the lowest efficient by pedal force efficiency. Circling is the MOST efficiency by the pedal force efficiency BUT is the lowest for the pedal cost.

The easiest example is if you have used Powercranks.... this kind of cranks increase a lot the pedal force efficiency during the pulling phase (ah I forgot to mention that hamstring is not the best muscle to measure to measure pedalling.. in fact posts is one of the strongest muscle in the body and is the main hip flexor and also the rectus femurs is a biarticular hip flexor) but Powercranks increase A LOT energy expenditure (VO2 and HR increase is significative).

I not think will be good to improve your pedalling techniques if you have an increase in energy expenditure. This excess cost is not reduced also training with Powercranks.
Flexor muscle have a max peak force lower than extensor (for the anatomy and function they are created for) and you will work at an higher % of your max force... so I can be wrong but this is not the way.

Andrea

bobbyjobling

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 #8 
I think changing cycling pattern can provide micro rest periods to the more used muscle in the cycling stroke. Efficiency based on power to Vo2 might be worse for short periods, but it might then increase the time to fatigue for the more efficient pedaling stroke.

Training the less efficient stroke should help increase the duration to fatigue as it will then require less energy to use it intermittently.
sebo2000

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 #9 

H Andrea,

 

Thanks for sharing, with your credentials you are the right guy to ask questions.

 

I totally agree about self-selected pedaling being most efficient, changing pedaling style totally destroys efficiency, when I was changing my pedaling technique I had to lower my power by 50%-60%, but despite that it felt I’m working out at 100% or close to it.

I was predominantly VL user, any off the saddle attack was making me useless for further in saddle follow up. Any in saddle longer hard acceleration was significantly affecting my off the saddle sprint.

I started practicing engaging hamstrings while seated, at 150W I blow my back after week or two, I was laughing to myself about how tired I am in recovery zone. My efficiency was really low. It took quite a while about 6 months (I’m actually still working on it 12 months later) before I could really use my hamstrings in racing. Now I slightly engage hamstrings in fast 60 seconds surges well above my FTP and still have completely fresh legs to cover sudden strong attack. I also started working on RF and VM and feel better than ever, but initially I could not agree more about efficiency, it was bad, until I trained those untrained muscles.

2 years ago on the trainer at 80% of my 60min power while going off the saddle for 5 min my HR was increasing 10-15bpm, now it stays the same at the same load.

 

Bobby has summarized my experience very well: “Training the less efficient stroke should help increase the duration to fatigue as it will then require less energy to use it intermittently.”

 

Without Moxy I would never be able to really pin point my weakness.

 

Andrea while you were working on your thesis did you have access to pro riders? I was always wondering how well or equally their muscle groups are developed? Do they all have different styles or their pedaling style would be similar in some way?

In many armature riders I have noticed big imbalances related to type of racing they do, “flat landers” will generally have less developed RF and VM from those that ride in hilly terrain etc. I found armature track riders having less imbalance than any others.

 

I’m experimenting with shorter 165mm cranks on my TT bike, can you share any info on that, it “feels better” as my hip angle opens up and I can breathe better, but I do not have more power, is this something worth exploring or it is waste of time?

 

Thanks

Andrea

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 #10 
Hi Sebo.
Yes "cycling" seems a simple task b ut inter/intra muscular activation can be quite different. We are working on "joint angle" using 3D motion cap system. I'm not meseauring activation pattern (EMG) or SmO2% for bike "optimization". Looking at pedalling techniques I have recorded the torque data using SRM in 3 times winner of the Paris Roubaix and this kind of riders was showing a very different pattern than classics sprinter/climber in fact they were showing a torque index (peak torque / avg. torque ratio) very high. Speculating this we have deduced this will permit to have a good "grip" on cobblestone and permit to maintain an higher average speed (jumping less on the cobblestone). Don't know if this was a "genetic" or trained "skills".
My first thesis was on pedal asymmetry in pro cyclist, second one (for the master) was on pedal force asymmetry.

Muscle "structure" is quite individual and I think in part is genetically determined. When you work on bike position they refere the feeling for example to move the work more on VM/VL than calf for example but generally the hamstring are more developed in rider that pulls the pedal for example out of the saddle... in short accelerating effort seated or out of the saddle. I didn't do n'analysis to determine muscle force balance (for example with isokinetic - CYBEX device).
I did the measure on 2 different riders (climber/sprinter) and what can I say is that a sprint (80kg) compared to a climber (60kg) shows:
@ 60°/sec   ~+40% force on extensor and ~+25% @ 60°/sec  but the ratio extensor/flexor was close to 55-60% on both.
@ 120°/sec difference was ~55% on extensor and ~45% on flexor... and extensor/flexor ratio close to 70%

From start of the season (after two months) peak of torque was decreased a bit (due to aerobic training?).

So muscle force / activation probably is also influenced by muscle characteristics and genetic other than task dependent.

On short cranks.... in the past on TT was suggested to use a longer crank compared to road... then moved to use same length... and someone now suggest to put shorter cranks to change hip angle / vertical displacement (to reduce aerodynamic drag and stay more stable with pelvis)... really I think is hard to demonstrate that efficiency is improved. Probably in a wind tunnel is possible to measure something different for the aero optimisation but also study on cranks length shows questionable results and in general for the field of application (normal cranks length goes from 165mm to 175mm) is hard to detect a parameter that change (HR, power, lactate, Vo2)... I not know if is a "sensibility" problem or not. But could be useful to find a parameter that permit to really optimise crank length (or bike position) ;-)

Andrea








dclarke

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 #11 
Great comments Andrea, very interesting.

Is your thesis available anywhere online or is it possible to share it?

Duncan
Takura

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 #12 
FWIW re crank length and pedaling, I had been using 165mm cranks on a 44cm road bike (am just 164cm@56kg) but noticed a strong limitation in left hip flexor motion range (which I am hoping to solve with some off the bike trainings) and went down to 150mm cranks on my TT bike. With the Leomo Type R introducing the concept of dead spots, I started to notice (or just imagine?) dead spots with the 165mm cranks on my road bike even without having bought into the Leomo sensors; am now trying 160mm cranks on one of my (road) bikes and the subjective pedaling smoothness of my left leg has improved significantly. Admit though that I haven’t been able to measure any power increases (yet). ;-)
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