The Optimum Hip Angle for Maximum power?

[Balor]

Anyway, I've did a set of blood pressure measurements, on my arm and on my calf. Results are... telling. (3 measurements with 1 minute between them, results averaged)

Arm, standing up:
121 : 69

Arm, sitting down:
132,3 : 78,67

Arm, lying down:
114 : 61,67

(That's rather interesting why my 'sitting up' pressure is so much higher compared to both lying down and standing up)

Calf measurement when standing failed - the meter pumps up to 250, blows some safety valve and gives out error. So it is safe to assume that when standing up, sistolic calf pressure is no less than 250

Calf measurement, sitting down:

185,67 : 124

Calf measurement, lying down (head propped up on a pillow)
138 : 69,67

Calf measurement, legs 12" higher than the head:

122,33 : 52,67

I've tried measuring blood pressure on my calf with legs held vertically up, surprisingly hard to do, so I've did only one measurement and got 80 : 30 despite my heart rate shooting up to 80 from 60.

Interesting article that might be relevant:

https://en.wikipedia.org/wiki/Orthostatic_intolerance

 

[Balor]

Again, I would be very grateful if other people, particularly those finding 'power gap' between a bent and a DF being narrow, would do same (at least arm/calf sitting up/lying down) set of measurements.

 

[Balor]

Reference pictures (pardon the hair, I'm no racer )

 

[Balor]

http://sci-hub.tw/10.1111/j.1365-2702.2005.01494.x
https://academic.oup.com/ajh/article/24/10/1073/2281918

Now that is interesting. According to this studies, it is normal for standing BP to be lower than while sitting, but emphatically NOT normal for supine position! It should, in fact, be higher. One study concentrated on young adults (students), the other on older people, I doubt my age is exceptional.
On the other hand, my circulation system certainly is (but not in a good way)... I'd really like for Jason to take some blood pressure measurements!

 

[ed72]

My BP cuff is whimpy but here are my numbers.

Measured in Left Leg
Sitting. 169/115 62 bpm
Laying legs at heart 151/64 61 bpm
Laying legs 12 inch high 115/49 61

Left Arm 118/76 59 bpm

HR is a little high but recovering from yesterday's sufferfest.

(I still have a power gap to DF for sure but from 5 minutes to 3 hours, it is under 15 % loss. For instance, I did 203 watts in the first 4 hours yesterday whereas on a DF, I would have expected more like 230 watts riding into the wind and a couple good climbs)

 

[Balor]

Well, that's interesting too.
You systolic BP when laying 'legs at heart' is much higher than mine despite your overall (and especially sitting) BP being lower.
Legs up position is similar given baseline (arm) pressure difference.

I bet your left arm BP is similar, or higher in supine position as it should be?
Where the hell *supine ortostatic hypotention* is supposed to come from in my case...

 

[Balor]

Ok, Wikipedia redirects "Supine hypotensive syndrome" to https://en.wikipedia.org/wiki/Aortocaval_compression_syndrome which proved to be a rather interesting read.

Well, I may not be a pregnant woman per se... but, unfortunately, I may look like one in lateral projection .
So, 'aerobelly' hurts one's climbing potential in more ways than one it seems... I'll need to take a prone BP measurement... more than that, I think I'll need to take BP measurements at various degrees of recline as well!

Oh, it is also corrected by laying on the side. Will need to check that as well.

 

[ed72]

Not sure if I wrote this anywhere but I have suspected visceral fat to press on the lungs in the supine position and is one reason in my opinion that effective breathing in the recumbent aka supine position is a little different than would be appropriate for runners, for instance. It is clear that visceral fat impairs lung function. At nearly 6'4'' and 214 lbs, I am 30 pounds over "racing weight" for my age and can lose probably 20 lbs subcutaneous and maybe 10 lbs visceral fat. Aside from any metabolic costs, that fat has to impair the motion of the lungs and therefore capacity, unless exercises and conscious efforts are made to counteract. I'm going to lose weight.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0193516

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940831/

 

[Balor]

Hey Ed, what kind of breathing excersizes did you use? This one, maybe?
https://www.bmj.com/content/332/7536/266

Seriously, I'd be grateful for a few pointers, it may benefit other bent riders as well.

 

[ed72]

Hey Ed, what kind of breathing excersizes did you use? This one, maybe?
https://www.bmj.com/content/332/7536/266

Seriously, I'd be grateful for a few pointers, it may benefit other bent riders as well.

Quick note.....have to run to PT.

look up Buteyko. I also used PowerLung. Shoulders set back on the seat (open cavity) and neck, too.....not bent and slouched. Do not bridge against shoulders (I know). Breath more controlled.....slower, especially at the start of a ride.....work a little slower into a threshold effort. Do not breath just from diaphram, chest needs to expand also. Both....I have no studies to support, just my observation and opinion. These comments apply to steady efforts (say Zone 2 or well below threshold).

Paradoxically, panting or excessive breathing lowers CO2 with negative consequence to VO2 max and also constricts vessels. I now inhale maybe three times per minute sitting one the couch. It is a paradox. Less is more. (not to dismiss perfusion adaptations in supine position)

Sorry have to run

https://www.normalbreathing.com/Articles-Breath-Exercise-for-Higher-VO2max.php

 

[Balor]

I also used PowerLung.

... 120$?
Something like this one I suppose?
https://ru.aliexpress.com/item/-/32864593703.html
Sheesh. Good idea though

look up Buteyko.

Hmm. I did and most articles are rather... sceptical. Why do you think this is particularly useful for bentriders in particular, or this is only related to your asthma?

I did read up on Bohr effect and related phenomena where too low CO actually reduced O2 availability to tissues, but it seems like people that would benefit from this technique are limited to sufferers from panic attacks...

 

[Balor]

https://www.strava.com/activities/1961283233/

An other test, best result yet:
Average 295, avg. aerobic - 284, anaerobic - 367 over 6 min, peak 30 sec - 581.

Again, with BB at seat level, recline about 30 deg, seat manipulated for 'cruzbike' profile. I attribute better results compared to previous test in similar position for training effect + (almost) no spasming this time. Hit highest HR yet - 181, for me that is a LOT.
Power drop with BB 12cm higher + lots of recline is truly colossal indeed...
(And basically, that would happen climbing 10+% hill. Much less power when you need it most )

 

[ed72]

I might have been borderline asthmatic but the bent position exasperates it. I was tested in the past when I was an upright rider but Doc said no asthma (I'd cough when doing very hard efforts in freezing temperatures.....intervals in 25-30F weather but fine rest of the year). He did breathing tests on me and then threw me out of his office, telling me I was his healthiest patient and stop exercising in cold dry weather. (Thanks, Doc). I was serious about not laying in a hospital bed if that time comes. Think about it....if a patient has breathing difficulty, do they lay them down? No, the patient is taken out of the supine position and put into a more sitting up position. It's physics and lung morphology/structure. In any case, it is very clear that the supine position is not the ideal one for V or Q and that a mismatch is likely to be a factor in the so-called bent legs phenomenon. I went from uprights (DF) to 19 degrees straight off. No gradual lowering of the seat. I immediately had difficulty breathing on hard efforts and would actually cough clear liquid. You are more bright enough to consider the changed pressure differentials from upright to supine and apply them to the Starling equation to at least not necessarily consider my experience to be isolated or due to some defective condition. At the very least, consider how very, very few recumbent riders claim to make the same FTP on a bent as an upright vs. how many claim that they make much less power on a bent. I am probably not going to get to my former upright power because age is getting the best of me; however, I am chipping away at it and am getting closer. What are the adaptations other than, grow them bent legs. My legs are still the same except the calves are much weaker.

Obviously, I cannot list all the factors why I had had a sharp increase in performance after 9-10 months of being kinda slow. However, I attribute some of it to better deliver of oxygen to the legs. When I lowered my seat, I was actually able to breath easier (and make more power) and this was another tip off to read up on how the lungs work. I might ask for railgun seat to be made for me. Nonetheless, I could have had a borderline or latent case of asthma that took 5 months to respond to medicine (inhaler) but that is not logical. V/Q mismatch due to supine positioning, especially with shallow belly breathing, is likely to result in CO2 levels that are also mismatched to the intended effort and the heart rate is then set too low. My heart rate would rarely go above 110 BPM and would maybe hit low 130's with a very hard perceived effort. I can now TT in the 155 bpm range on my bent whereas 167-171 would have been my range on an upright. So, I hope for 10% more improvement in FTP on my bent. I need to do a FTP test but my TSB is sitting on -54.....not a good place to test off.

WRT to optimum hip angle, who knows. I have a note from a gentleman who rides (very fast) with an 8 degree seat who makes a ton of power and who thinks lots of power can be made with a low seat.

 

[ed72]

https://www.strava.com/activities/1961283233/

An other test, best result yet:
Average 295, avg. aerobic - 284, anaerobic - 367 over 6 min, peak 30 sec - 581.

Again, with BB at seat level, recline about 30 deg, seat manipulated for 'cruzbike' profile. I attribute better results compared to previous test in similar position for training effect + (almost) no spasming this time. Hit highest HR yet - 181, for me that is a LOT.
Power drop with BB 12cm higher + lots of recline is truly colossal indeed...
(And basically, that would happen climbing 10+% hill. Much less power when you need it most )

Wow.

How much percentage wise improvement?

Can I have your numbers?

I forget why but I had concluded that that S30 or john morciglio's blue MBB bent would be the ideal configuration for climbing and good flat performance for hilly brevets. The Hammerhead also has a fairing over the front tire, this front tire creates a lot of drag at the top.

 

[ed72]

Perhaps classic "Analysis Paralysis".

Hardly.

I went from 26 minute 10 mile TT down to 20 minutes and will break 19 minutes next year among other personal achievements, none of which could or will have happened if I continued to listen or follow what has passed for knowledge with most bent riders. Most bent riders never road with a power meter when they were on a DF and if they did, they did not analyse performance nor did they use a coach to do the performance analysis for them. Thus, most are clueless. The handful who may know something? There is a pattern. They eventually just log off.

I do appreciate your kind sentiment.

 

[ed72]

Balor......forgot the shoulder and pec minor doorway stretches. I do them every day since April. Opens chest up.

 

[Balor]

What are the adaptations other than, grow them bent legs. My legs are still the same except the calves are much weaker.

Well, admittedly 'bent legs' is like 'dark matter' - it just puts the name on observed phenomena (missing mass or missing power), but whether this is 'matter' (or 'legs') seems like intuitive, but not a proven causal explanation. And few things are intuitive when you comes to gravity/QM or biomechanics .

Can I have your numbers?

Why, easily. Install 20" *front* wheel on your CHR and multiply your watts by 10%. I guess you'll have that and more Plus, you'll have my speed as well (mere 38 kmh TT on flat), ehehe. (But I'm not sure that configuration would be rideable - you'll likely get negative trail... only if reverse your fork.)

The handful who may know something? There is a pattern. They eventually just log off.

Why, if you take someone like Osiris, who is quite content with flat TT performance (as in - KOM hunting) and extra comfort bents provide... we'll, you've seen his posts. Vendetta/CHR, despite power drop he also experiences and quote open about, are much faster for him even into modest uphills due to much greater aero efficiency. So, what's not to like? And you are already faster on most mixed roads as well, right?

Plus, what's the point of training on a platform you will not be allowed into any serious competition if you care about such things? Allowing a much greater assortment of bikes (including bents) into triathlons would be a great boon for the industry and we'll finally see some *serious* folk taking a good look at bents.

In my case power drop is particularly egregious when it comes to BB above seat and having it lower comes at a cost of aerodynamics that is only about of a CX bike in the drops. I'm seriously considering a prone bike now...

 

[Balor]

He did breathing tests on me and then threw me out of his office, telling me I was his healthiest patient and stop exercising in cold dry weather. (Thanks, Doc).

That reminds me of a Russian joke (maybe you have an analogue):

A patient comes to the doctor:
- In the morning, when I bend down low, then straighten up and rise my right and left leg in succession, I get weird spells of dizziness. What's wrong?
- Well, you are not a young man, maybe you should stop doing such acrobatics?
- Acrobatics? I'm just putting on my pants!


Well, admittedly, I also get absolutely same symptoms in same conditions. Dunno, maybe I am also pre-asthmatic? But I only got breathing problems after a lot of 'bent saddle time' AND lowering my BB significantly. Otherwise, like in your case, I got extremely low HR that simply refused to get up because my legs simply felt weak and hurt a lot after trying to push for power, I was not even breathing hard. And it seems very common...

 

[bladderhead]

Balor does not have COPD. My lungs, not my legs, limit my watts.

I always wondered why downhill is so much easier than uphill. Now I know. When you are going uphill the BB is raised. Downhill, and the BB is lowered. That explains it.

 

[Balor]

I always wondered why downhill is so much easier than uphill. Now I know. When you are going uphill the BB is raised. Downhill, and the BB is lowered. That explains it.

Well, it also explains why bents are so much faster downhill than DF bikes - their BB goes up downhill .
But to be serious, I think anyone can do a similar experiment as I did on a FWD bent - just remote your rear wheel (you'll need some sort of support, I've used 10mm threaded road and pieces of 3D printed plastic) and see whether you'll be able to match your power output. (Will work fine on S40, I think that might be bit too drastic on Vendetta).
Add a (decently high) rear wheel support, like a few stacked books for instance, to see how it will affect your power, too, to simulate pedalling downhill.