Powercranks



[email protected] (Carl Fogel) wrote in message news:<[email protected]>...
> [email protected] (Frank Day) wrote in message
> news:<[email protected]>...
> > It is unlikely that the PowerCranks "work" as a result of either the Hawthorne effect or placebo
> > because the first experience of every user is a substantial worsening of performance. Only after
> > several weeks or months effort do the benefits become evident, although the typical new user can
> > see the potential for benefit almost immediately.
> >
> > Frank (inventor of PowerCranks for those who don't know me)
> >
> [snip]
>
> Dear Frank,
>
> How does a substantial worsening of performance make a potential benefit almost immediately
> visible to the typical new user?
>
> Carl Fogel

It is probably because the initial struggle doesn't last too long, as most people see improvement
starting with the second ride (at least improvement from their first ride effort). Beyond that, I
think it is now because they know these are making them do what people have been telling them they
should do, and what they thought they were doing but now know they were not combined with having
seen or heard of improvements coming from others. It is this ability to see improvement (or change)
coming reasonably quickly that keeps people going. If it took 2 years it is unlikely that anybody
would do it.

In the beginning it was not obvious to users and many egos have gotten in the way of people getting
through the adaption. It took a lot of effort to get some of the first to do it right, ask Phil
Holman. People do not like change just for change sake.

Frank
 
Terry Morse <[email protected]> wrote in message news:<[email protected]>...
> Frank Day wrote:
>
> > Rowers and XC skiers have higher VO2 max capabilities than runners and cyclists because they use
> > more muscle mass in their sports.
>
> More accurately, it's because they use more muscle *groups* in their sports. Along with those
> additional muscle groups come more blood vessels to carry in the oxygen and carry away the waste
> products. If muscle mass alone were the limiting factor, one could simply build up one's quads in
> the gym to produce a higher VO2max. If only it were that simple.

Actually, it is that simple. I should have specified it is the mass of muscle being used aerobically
(and the effort being expended also). A sedentary person has a limited VO2 max. With training
however, they can increase that. It is not required that they increase the amount of muscle they
have but, rather, they must simply train to increase the blood flow they can deliver to those
muscles they already have. The caardiovascular system adapts.
 
Sheldon Brown <[email protected]> wrote in message news:<[email protected]>...
> Carl Fogel queried:
>
> > On a related note, why do distance swimmers use both their arms and legs? Why do cross-country
> > skiers use their poles while striding? I'm ignorant of these sports, but have the impression
> > that they involve using all four limbs, not just two, and make huge cardiovascular demands.
>
> I can answer that.
>
> A bicycle has a very efficient drive train, solidly coupling the legs to the propulsion system.
> There are small frictional losses, but virtually no slippage to the drive train.
>
> A swimmer or skier has a very much less efficient way of converting leg effort into propulsion due
> to the natures of the respective media.
>
> A skier does have good coupling for the arm component of propulsion, but arms are way weaker
> than legs.
>
> Sheldon "Impedance Matching" Brown
I am by no means a fish but I believe the answer is quite simple. Competitive swimmers tend to kick
in the manner that gets them from point a to point b fastest. Kicking is a less efficient method of
propulsion than the arms but it does add something. But, in addition, the kick also keeps the legs
up, reducing drag. This is probably more important in the water than on the bike.

So, distance swimmers tend to kick very little, just enough to keep the legs up, while sprinters
tend to kick a lot, trying to get every ounce of propulsion out of their legs. Mid distance do
something in between. It is all about the best use of the available energy for the event. Hmmm.
Isn't this what this debate is about? Guess cyclists and swimmers do have something in common.
 
"Hjalmar Duklæt" <[email protected]> wrote

> > Your "back stroke" muscles only have about 10% of the power of your "fore stroke" muscles, so
> > 100% use would make you 3% faster. That's if you weren't already cardio-vascularly limited, and
> > didn't suffer
from any
> > overhead or inefficiencies in recruiting the extra muscles.
> >
> Where have you got this information. You're saying that I'm not able to lift more than 12.5 kiloes
> with one foot. Even though I've not tested this I'm quite sure I'll do much more than that. I know
> I can (or at least could a couple of years back) lift 250 kiloes with my feet. i.e. 125kiloes on
> each foot. 10% of that is 12.5 kiloes.

Check out : http://www.analyticcycling.com/PedalModelConcept_Page.html for a description of
pedaling dynamics.
 
"Robert Chung" <[email protected]> wrote in message news:<[email protected]>...
> peterwright wrote:
> >
> > I am interested in the notion of cycling performance being limited solely to cardiovascular
> > function. If this is the case then why do we do any specific training - for example hill
> > repeats, speedwork etc ? If the only way to ride better is to improve Vo2 then we should all be
> > training on indoor trainers at the same relative intensity to ensure maximum improvement. Surely
> > improving muscular strength has got to have an impact (along with Vo2) on cycling performance ??
>
> Hill repeats and speedwork increase one's aerobic capacity.

That is because aerobic capacity follows the muscle capacity. sports activities are not limited by
the ability of the heart and lungs but by the limiting muscle or muscle groups going anaerobic.
Improve those limiting muscles and your performance will improve (however then you will have a new
limiter though that will need to be improved if you want to improve further but it won't be the
heart or lungs).

The other way to improve performance is to improve the efficiency of the trained muscles to get more
out of what they have. One can only improve doing one or both of these approaches

It is that simple folks.
 
In article <[email protected]>,
Frank Day <[email protected]> wrote:
> Competitive swimmers tend to kick in the manner that gets them from point a to point b fastest.
> Kicking is a less efficient method of propulsion than the arms but it does add something. But, in
> addition, the kick also keeps the legs up, reducing drag.

You may be right. However, my experience this morning in the pool (this is co-incidence: I had other
reasons to be studying the relative effects) was I think slightly different. Bear in mind that I'm
most certainly _not_ a competitive swimmer.

I held my stroke rate (`cadence') as level as I could, while focusing additional effort first into
my arms, then my legs. I can't define `effort' in any useful way, I'm afraid. My forcing my arms
harder against the water, I raised my heart rate a little and dropped my usual 45s/25m lengths to
maybe 40s.

Focussing additional effort into my legs dropped the time to 35s while driving my heart rate from
125 to 155 in the space of those 35 seconds.

I suspect Sheldon's ``impedence mismatch'' comment is the heart of this: for whatever reason, I
could couple my legs into the water better than my arms.

ian
 
"Per Elmsäter" <[email protected]> wrote in message
news:[email protected]...
> Robert Chung wrote:
> > peterwright wrote:
> >>
> >> Yes, but so does flat steady road work at the correct intensity so why bother with hills etc ?
> >
> > 1. Different inertial loads.
> > 2. Trainers are mind-numbing.
>
> So are you saying that basically any training that takes the HR up far enough and long enough will
> increase aerobic performance?

Yes - and he's right.

Andy Coggan
 
"Frank Day" <[email protected]> wrote in message
news:[email protected]...
> aerobic capacity follows the muscle capacity. sports activities are not limited by the ability of
> the heart and lungs but by the limiting muscle or muscle groups going anaerobic.
>
> It is that simple folks.

Sorry, but it's not that simple. First, skeletal muscle is not anaerobic at any intensity less than
100% of VO2max. Second, convective O2 delivery (determined by cardiac output and arterial O2
content) does indeed limit aerobic capacity (i.e., VO2max).

Andy Coggan
 
Frank Day wrote:

> That is because aerobic capacity follows the muscle capacity. sports activities are not limited by
> the ability of the heart and lungs but by the limiting muscle or muscle groups going anaerobic.
> Improve those limiting muscles and your performance will improve (however then you will have a new
> limiter though that will need to be improved if you want to improve further but it won't be the
> heart or lungs).
>
> <snip>
>
> It is that simple folks.

It's not quite that simple. Athletic peformance requires a system to work together. Let's assume
(naively) that the limit of performance is the lactate threshold. There are several factors that
affect the lactate threshold, muscle adaptations (mitochondria density, capillary density, fiber
type) being only one. There is also the blood flow capability of the heart, and the ability of the
heart, liver, and kidneys to clear the lactate from the blood. (There's also the ability of a
trained athlete to tolerate elevated blood lactate levels, but that violates our naive assumption).

Here's a good overview article on lactate threshold:

http://home.hia.no/~stephens/lacthres.htm
 
Frank Day wrote:
>
> The other way to improve performance is to improve the efficiency of the trained muscles to get
> more out of what they have. One can only improve doing one or both of these approaches
>
> It is that simple folks.

What's the link between improved efficiency and improved power?
 
"Phil Holman" <[email protected]> wrote in message
news:[email protected]...

> And it just so happens that the limiting factor for cycling occurs at the point when the quads and
> glutes are fully developed and engaged and not one muscle fibre more (tongue in cheek) What a
> coincidence.....don't you think?

Never heard of the principle of symmorphosis, eh Phil?

Andy Coggan
 
Andy Coggan wrote:
> "Per Elmsäter" <[email protected]> wrote in message
> news:[email protected]...
>> Robert Chung wrote:
>>> peterwright wrote:
>>>>
>>>> Yes, but so does flat steady road work at the correct intensity so why bother with hills etc ?
>>>
>>> 1. Different inertial loads.
>>> 2. Trainers are mind-numbing.
>>
>> So are you saying that basically any training that takes the HR up far enough and long enough
>> will increase aerobic performance?
>
> Yes - and he's right.
>
> Andy Coggan

OK. So if I up the "cadence" when doing squats in the gym. Enough to be close to an LT HR after each
set. Will I then both build my legs and aerobic capacity at the same time?

Another side question when I have both of you in this thread ;) which btw is one of the most
interesting threads this week. Yesterday I got dropped on the trainer doing my 2*20 Power intervals
;) After 14 minutes my HR had slowly raised above my LT at a constant Wattage. At this point I just
had to quit and went into recovery instead. After 20 minutes of recovery I tried my second set but
there was no way I could get back into the race again. This will probably not be the last time this
happens, either due to an infectrion or just from raising the wattage to high. In my case I probably
raised the wattage to fast. So what could a good plan B look like? I'm on the trainer but can't go
all out with the 2*20s. Would for instance microintervals be a good substitute or might I just as
well just spin my way out of this training session?

--
Perre

You have to be smarter than a robot to reply.
 
"Frank Day" <[email protected]> wrote in message
news:[email protected]...
> Rowers and XC skiers have higher VO2 max capabilities than runners and cyclists

No, they do not, at least not when the effects of body size are properly taken into consideration.

Andy Coggan
 
Frank Day wrote:

> Terry Morse wrote:
>
> > More accurately, it's because they use more muscle *groups* in their sports. Along with those
> > additional muscle groups come more blood vessels to carry in the oxygen and carry away the waste
> > products. If muscle mass alone were the limiting factor, one could simply build up one's quads
> > in the gym to produce a higher VO2max. If only it were that simple.
>
> Actually, it is that simple. I should have specified it is the mass of muscle being used
> aerobically (and the effort being expended also). A sedentary person has a limited VO2 max. With
> training however, they can increase that. It is not required that they increase the amount of
> muscle they have but, rather, they must simply train to increase the blood flow they can deliver
> to those muscles they already have. The caardiovascular system adapts.

Thanks for the clarification, but I have one more question. When you write "it is that simple", are
you claiming that building up muscle mass through weight training will improve one's VO2max? As far
as I know, weight training does nothing for cardiovascular fitness.
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/
 
"Andrew Bradley" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Frank Day) wrote in message
news:<[email protected]>...
>
> >Most significant to my mind was the improvement in pedaling efficiency (watts per VO2 uptake)
> >from 21 to 23% which correlated with a 14 bpm drop in HR at the same power (155 to 141) if I
> >remember the number correctly. The non PC group showed some improvement but it was insignificant
> >statistically. There was no improvement in VO2 max at the end for either group.
>
> If you said "Powercranks are more efficient" I'd say yes, because you use a lower cadence and
> lower cadence is more efficient. But here cadence was fixed at 80rpm.
>
> Are these the results you expected? I would have thought, if anything, VO2 max would have come out
> higher due to the "more muscle groups" thing.
>
> Do you have an explanation of what was found here?
>
> The study didn't come up with a convincing explanation, especially not (speaking of training the 9
> o'clock to TDC sector):
>
> "Training this third phase with powercranks may give a more effective pedal stroke, reducing or
> eliminating any negative torque produced (and thus, wasted energy) and allowing more energy to be
> transfered to the forward movement of the bicycle."

The study in question also didn't have an appropriate "attention control" group - which may explain
why it was published in the journal that it was.

Andy Coggan
 
[email protected] wrote in message
news:<[email protected]>... [snip]

> I think if you review what I wrote that it is unambiguous and only willful misinterpretation ...

Willful misinterpretation? Mr. Carl Fogel? Perish the thought!

LOL.

Sarcasm brought to you by,

R.F. Jones
 
Peter Wright writes:

> I am interested in the notion of cycling performance being limited solely to cardiovascular
> function. If this is the case then why do we do any specific training - for example hill repeats,
> speedwork etc ? If the only way to ride better is to improve Vo2 then we should all be training on
> indoor trainers at the same relative intensity to ensure maximum improvement. Surely improving
> muscular strength has got to have an impact (along with Vo2) on cycling performance?

Because the muscles must be there in the first place and the body responds to exercise by building
them up. Without exercise the muscles atrophy as we have learned from space travel in the absence of
gravity that makes muscles work.

Jobst Brandt [email protected]
 
Robert Chung writes:

>> The question seems to be how do various combinations of limbs affect the ratio between effort and
>> cardiovascular limits.

http://tinyurl.com/3edqs

The upshot is at the end of this item:

# The important point is that greater metabolic and physiologic strain accompanies a standard
# submaximal power output or oxygen uptake with the arms (McArdle et al., 1996; Rowell, 1993). At
# maximal effort, however, physiological responses are generally greater in leg exercise than arm
# exercise (Franklin, 1985).

Jobst Brandt [email protected]
 
Phil Holman wrote:

>>> And it just so happens that the limiting factor for cycling occurs at the point when the quads
>>> and glutes are fully developed and engaged and not one muscle fibre more (tongue in cheek) What
>>> a coincidence.....don't you think?
>>
>> Huh? The limiting factor in cycling becomes the cardiovascular system before the quads and glutes
>> are "fully developed" -- so why would developing these muscles further change that?
>
> How so? Athletes converting from other sports take several years to fully develope their cycling
> ability despite excellent cardiovascular fitness. The limiting factor is at the muscle cell level.
> Sports that utilize more muscle mass demonstrate higher oxygen utilization.

So? Assuming your not including sprinting as part of cycling ability, this probably just means that
for these athletes the limiting factor is the leg muscles -- but only until these muscles catch up
to their cardiovascular system. Any further muscle development will have no affect on their cycling
below anaerobic levels.

--
Benjamin Lewis

Now is the time for all good men to come to.
-- Walt Kelly
 
"Per Elmsäter" <[email protected]> wrote in message
news:[email protected]...
> Andy Coggan wrote:
> > "Per Elmsäter" <[email protected]> wrote in message
> > news:[email protected]...
> >> Robert Chung wrote:
> >>> peterwright wrote:
> >>>>
> >>>> Yes, but so does flat steady road work at the correct intensity so why bother with hills
> >>>> etc ?
> >>>
> >>> 1. Different inertial loads.
> >>> 2. Trainers are mind-numbing.
> >>
> >> So are you saying that basically any training that takes the HR up far enough and long enough
> >> will increase aerobic performance?
> >
> > Yes - and he's right.
> >
> > Andy Coggan
>
> OK. So if I up the "cadence" when doing squats in the gym. Enough to be close to an LT HR after
> each set. Will I then both build my legs and aerobic capacity at the same time?

Only if you reduce the resistance to the point that you can continue doing squats at that increased
cadence for many minutes at a time.

> Another side question when I have both of you in this thread ;) which btw
is
> one of the most interesting threads this week. Yesterday I got dropped on the trainer doing my
> 2*20 Power intervals ;) After 14 minutes my HR had slowly raised above my LT at a constant
Wattage.
> At this point I just had to quit and went into recovery instead. After 20 minutes of recovery I
> tried my second set but there was no way I could get back into the race again. This will probably
> not be the last time this happens, either due to an infectrion or just from raising the wattage to
> high. In my case I probably raised the wattage to fast. So what could a good plan B look like? I'm
> on the trainer but can't go all out with the 2*20s. Would for instance microintervals be a good
> substitute or might I just as well just spin my way out of this training session?

"Spin your way out", take it easy for a day or two, then try again at a reduced power goal.

Andy Coggan