Climbing vs testing: same power, different cadence. Why?

BenderRodriguez

Here is something that I have been wondering about for a while, and have yet to see a fully satisfactory explanation.

When riding at threshold in a time trial or on the track my preferred cadence is 100 - 105 Rpm and anything below 90 feels like I am riding though treacle.

When riding at threshold on a climb of say, 7 - 8%, my preferred cadence is around 80 Rpm, a big difference. What's more 90 Rpm feels like I am almost over-revving.

Question is, why such a difference? I have read a lot on the selection of an optimal cadence, with factors such as maximising the available oxygen, the optimal recruitment of 'fast' versus 'slow' twitch muscle fibres and so on, but all of these explanations would seem to be equally applicable to riding on the flat as on a climb, and so should produce a very similar 'optimal' cadence in each situation. Also, the power output in each case is the effectively the same.

I have seen it suggested that on a climb the 'dead spots' are much more pronounced because of the gradient. If this is the reason for the difference than it seems that pedalling technique is, after all, crucial with, one would assume, a lowered cadence allowing a more 'rounded' pedalling action with more time being available to coordinate the muscles to 'push' and 'pull' through the top and bottom dead spots. However, even if this were the case, why not 'naturally' adopt a similar style when testing or, conversely, why not simply raise the cadence to minimise the time that the legs are passing through the 'dead spots'?

If overcoming such 'dead spots' via a modified pedalling style is indeed the reason, how does this sit with those who argue that pedalling style is an irrelevance and all that matters is pushing hard on the down-stroke?

Another possible reason is simply habit, with people habitually over-gearing on climbs until it becomes psychologically ingrained. Certainly, I was brought up at a time when 42 x 21 was though to be a real 'Alpine' gear and we though nothing of youth hostelling in the winter on 61 fixed, grinding over every climb in the Yorkshire Moors and Dales at a stupidly low cadence. However these days, what with compacts and so on, I certainly have the gears needed to do 90 Rpm plus on a climb, but doing so just doesn't feel 'right' and I always end up dropping a cog or two and my cadence along with it.

Any thoughts?

Max Bridges

Power is power. Cadence should be self selected. Cadence is a red herring. How do you expect people to sell coaching services and power software if you keep posing such irritating questions?

Pedalling technique is misleading, at best confusing.

Stop,this,trolling Bender, really winds up the usual suspects. Power is power al this talk of cadence is mere trolling.

BenderRodriguez

I am not trolling here!

Say I produce 300 watts at MLSS and in order to produce this power a time trial I 'naturally select' 100 Rpm on 53 x 13, with a corresponding torque demand at the pedals. On a climb I will be going more slowly but also have lower gearing available, so it seems that when I am putting out the same power on a climb I should be able to duplicate the same balance of cadence versus torque that I naturally select on the flat simply by selecting an appropriate gear. However the reality is that I, and it seems most other riders, instead select a cadence that is perhaps 20% or even more lower, with a corresponding increase in the torque needed to generate the same power.

On a climb I may be consciously aware of what the resistance is that I am pedalling against, but do my legs themselves 'sense something' about the demand placed on them and so function in a different way? If so, how on Earth does that work? Surely power is power and torque is torque, so far as the leg muscles are concerned?

By the way, I am not trying to argue that this 'proves' that what is happening here is that riders adopt a different, 'rounder' pedalling style in order to minimise the duration of the 'dead spots'. Maybe this is the case but if overcoming 'dead spots' is really such an issue why, for example, doesn't going from a freewheel to a fixed also influence cadence selection given that a freewheel needs to be carried past the dead spots by the rider, whilst a fixed wheel will naturally carry the rider's legs through them? OK, so the amount of muscular effort needed to simply pedal though these points is minimal, unless one is actually trying to actually generate enough torque to contribute significantly to the torque curve, but most riders don't seem to do this. They probably don't do it when climbing either!

This is such an obvious question, someone must have done some research into it. Surely, someone amongst all those who have looked at pedalling styles and torque curves must have thought to compare riding on the flat as opposed to riding on an inclined plane?

jibberjim

Why not look for the research yourself rather than just expect everyone else to spoon feed you?

http://www.ncbi.nlm.nih.gov/pubmed/8945654
http://www.ncbi.nlm.nih.gov/pubmed/11784546

took me 2 seconds...

BenderRodriguez

jibberjim wrote:

Why not look for the research yourself rather than just expect everyone else to spoon feed you?

http://www.ncbi.nlm.nih.gov/pubmed/8945654
http://www.ncbi.nlm.nih.gov/pubmed/11784546

But those references don't explain at all why self selected cadence on a climb is lower than for the same power output in a time trial.

For example, this study, http://www.ncbi.nlm.nih.gov/pubmed/11784546 found:

Freely chosen pedal rate was higher at high compared with low crank inertial load... Along with freely chosen pedal rate being higher, gross efficiency at 250W was lower during cycling with high compared with low crank inertial load.

So, they found a high crank inertial load (produced by riding a bigger gear on the flat) led to a higher freely chosen pedal rate. Doesn't this just confirm what we know already about the differences regarding cadence selection on the flat versus a climb?

This study, http://www.ncbi.nlm.nih.gov/pubmed/8945654 found:

muscle coordination during steady-state pedaling is largely unaffected, though less well regulated, when crank inertial load is increased.

So, how does this in any way explain the adoption of a lower cadence when climbing, other than suggesting that it might not be due to an adaptation of the pedaling style in order to better overcome the increased inertia through the top and bottom 'dead spots'?

xavierdisley

BenderRodriguez wrote:

So, they found a high crank inertial load led to a higher freely chosen pedal rate. Isn't this exactly the opposite of what is found on a climb when the higher inertial load due to the gradient

BenderRodriguez

xavierdisley wrote:

BenderRodriguez wrote:

So, they found a high crank inertial load led to a higher freely chosen pedal rate. Isn't this exactly the opposite of what is found on a climb when the higher inertial load due to the gradient

Thank's for highlighting my error! I have found a copy of the original paper which explains this point much more fully. (See below). I'll read it to see if it answers my questions.

http://www2.mae.ufl.edu/~fregly/protect ... jb2002.pdf

BenderRodriguez

OK, a little additional reading and thought later...

It seems that, in order to better understand what the papers linked to earlier are actually showing us, we need to have a clear understanding as to what crank inertial load actually is. I haven't found a good definition but I think this is what is meant. Something that has a high inertia has a tendency to continue to move at the same velocity, hence a cyclist going along a flat road has a high inertia, whilst one going up a steep hill will not, tending to slow down and stop quickly. I assume that 'crank inertial load' is a measurement of this inertia, as would be measured at the cranks. So, a state of high crank inertia will exist when speeding along on the flat in 53 x 13, and a state of low crank inertia will exist when going up a hill in 34 x 23, even if the cadence is the same.

So, why is there a tendency to select a lower cadence in response to a condition of low crank inertia? It seems that this goes straight back to the issue of how the neuro-muscular system responds to those 'dead spots' in the pedalling stroke, which in a low crank inertia situation (as in climbing a hill) will be much more pronounced.

I have seen a similar discussion from Alex Simmons with regards the differing actions of turbo-trainers:

Inertial load is the next main differential factor when comparing indoor and outdoor training. Without going into too much detail, when we ride outdoors, we have the inertial load of a bike and rider moving at some speed, plus that of the wheels turning. If we stopped pedaling, our rear wheel doesn't suddenly slow or stop turning, we would coast for quite some time. On many trainers however, since we are not moving, the inertial load is much less and confined to the rear wheel spinning and any small flywheel that the trainer has attached to the roller. When you stop pedaling, the wheel slows and comes to a halt relatively quickly. Some are worse than others.

Now what happens is each scenario feels quite different to ride, muscle activation is different, the neuromuscular demands are different and these can be enough for some to make power production much harder. In general, low inertial load trainers tends to emphasise the "dead spots" in the pedal stroke (when the cranks are passing through the 12/6 O'Clock position), whereas riding with a higher inertial load enables one to breeze through (and not waste effort on) the dead spots and focus on the downstroke where the bulk of power is produced.

Fortunately there is a way to increase the inertial load of a trainer, and that's by having a flywheel attached to the trainer's roller (or even by adding mass to the wheel itself). How much mass is needed? Well to replicate the inertial load of a rider, it would need a very heavy flywheel spinning very quickly. Think of a 20-30kg flywheel spinning at 500-800 rpm. Yikes!!

http://alex-cycle.blogspot.fr/2009/01/t ... ining.html

So it does seem that the lower cadence could well have something to do with managing those 'dead spots' more effectively. Question is how is this done, given that some studies indicate this lowered cadence does not lead to a modification in the torque profile / pedalling style? Also, if these "dead spots" are so problematical, why isn't the preferred response to raise the cadence so as to pass through them as quickly as possible and so get to the 'downstroke where the bulk of power is produced'?

If this lowered cadence is in fact adaptive and positive, does this not imply that:

1) one should specifically train at such cadences when climbing and,

2) that training done in a high cadence / high crank inertia condition might not transfer well to lower cadence / low crank inertia conditions?

(I certainly seem to have found that my increase in FTP developed at high Rpm on the track this winter has not transferred that well to long rides that contain a high percentage of climbing.) Alex Simmond's blog certainly seems to suggest this when he notes "what happens is each scenario feels quite different to ride, muscle activation is different, muscle activation is different, the neuromuscular demands are different and these can be enough for some to make power production much harder"?

I also recall that Graham Obree's book advises doing the very opposite to what Alex Simmons advises, taking off any flywheel that one might have on one's trainer, so as to better develop the neuro-muscular system to ride through those dead spots, rather than relying on the flywheel on the turbo to do this for you!

There is just one more thing to be done to your turbo to make it conform to the ‘Obree Way’ of training. This is optional but advisable. Every commercial turbo comes with a fly-wheel on the opposite side from the magnetic unit. I ask you to remove it or have your local shop remove it for you. It may be worth telling them that it is most likely fitted using a ‘left hand thread’. The reason for this is that pedalling is as complicated as a swimming stroke and certainly not an up and down affair. Removing the flywheel will help train an all round more efficient stroke. I explain all in the section about pedalling, but for now, trust me, and get rid of it!

So, conclusions so far? A lowered cadence when climbing is something to do with adapting ones pedalling style so as to overcome the prominent "dead spots" cause by riding in a state of low crank inertia. As such there must be more to pedalling than just pushing down, at least when climbing. It may also be a positive adaptation and one that should be specifically trained for, rather than trying to ignore it and instead adopt a higher cadence which in reality 'works best' in conditions of high crank inertia.

Maybe!

Barteos

IMO it's psychological.
When climbing, we're frustrated that aren't able to maintain a decent speed and we're trying to pedal at lower rpm coz it feels "harder"/faster. Spinning 90rpm at e.g. 10mph feels like not going anywhere...
Have a look at forums and you'll find post from people who believe that picking lower gear and spinning when climbing "slows them down"

BenderRodriguez

Barteos wrote:

Have a look at forums and you'll find post from people who believe that picking lower gear and spinning when climbing "slows them down"

To be fair, there is evidence showing that a higher cadence places higher demands on one's oxygen supply system than a lower one. Of course, that raises the issue of why people tend adopt a higher cadence when on the flat
for the same power output, which is what the discussion is all about here.

I have long thought that the high cadence and yet bio-mechanically inefficient climbing styles of people like Armstrong and Basso were only possible because blood doping and Epo use raised the ceiling on the amount of oxygen that they could supply. This high cadence style was probably of benefit because it then allowed them to minimise the recruitment of fast-twitch muscle fibres, reduce the incidence of DOMs and benefit from enhanced recovery in general.

xavierdisley

BenderRodriguez wrote:

So, why is there a tendency to select a lower cadence in response to a condition of high crank inertia?

BenderRodriguez

xavierdisley wrote:

BenderRodriguez wrote:

So, why is there a tendency to select a lower cadence in response to a condition of high crank inertia?

Thanks for pointing out my typo! Fixed now.

wongataa

The difference could be down to the fact at lower cadences the torque will be higher for a given power output. Higher torque could well be useful going uphill.

BenderRodriguez

wongataa wrote:

The difference could be down to the fact at lower cadences the torque will be higher for a given power output. Higher torque could well be useful going uphill.

But that torque is transferred through the gears which are lower for climbing.

Also, power is simply force x distance / time, so if my power at 'threshold' is fixed at 300 watts, and my cadence and crank length are fixed, then surely the force (torque) that is required at the cranks will be the same whatever I am doing? That is, it shouldn't matter what the resistance is that I am overcoming: riding up a slope or against the resistance caused by riding at 30 Mph on the flat. The only difference is that on a climb the torque at the cranks will be geared up more at the rear wheel, increasing the torque at the wheel along with reducing the rotational speed.

I do think that this crank inertial load thing is key to understanding this, but this suggests that pedalling is not just a case of pushing down on the cranks, at least when climbing.

Another issue is that the studies into crank inertial load I have read so far seem to suggest that the reason why the cadence is increased when there is a condition of high crank inertial load is that this enables the peak torque needed to be reduced. But if so, why doesn't this effect happen when climbing when the gradient / lower cadence would, or one would think, actually make the peak torque higher than revving away on the flat?

Perhaps what is happening is that when climbing the torque is applied in a much more sustained manner, reducing the peak torque needed that way, but in turn demanding a lower cadence in comparison with riding on the flat when a high revving but 'punchier' pedalling style works best.

This does seem to make logical sense, as if you have a constant, high resistance to work against with a tendency to 'stall' if the pressure is eased off, as when riding up a hill, it seems to make sense that the best way to over come this resistance to to apply torque for as long as is possible during each revolution. Conversely, when there is a lot of momentum, one can simply keep giving a 'kick' of power, much like when giving a strong, sharp pull to spin up the fan on a Concept 2000 rower.

It could also be that those studies that appear to have shown that pedalling style is an irrelevance, and all that really matters is pushing down on the pedals, only reached this conclusion because they did not tests the subjects under conditions of low crank inertia, and that their findings are only true for conditions of high crank inertia.

Or something!

darkhairedlord

using the same power on the flat as up hill is inefficient and your body knows this, so it is trying to slow you down

ariege_cyclist

Due to the gradient of the climb your body feels like it is further behind the bottom bracket (the opposite of a TT frame position) so there is a change in muscle recruitment. I think this has some effect in addition to the low inertia. I need to try the turbo jacked up to a 10% gradient!

BenderRodriguez

Ariege cyclist wrote:

Due to the gradient of the climb your body feels like it is further behind the bottom bracket (the opposite of a TT frame position) so there is a change in muscle recruitment.

If that were the case Steve Bauer must have been doing 20 Rpm when he rode that laid-back bike in Paris Roubaix and Ghent-Wevelgem.

http://www.bikehugger.com/post/view/the ... erckx-ever

P.s. Don't recumbent riders tend to use the same cadences under the same conditions as those on normal bikes?

BenderRodriguez

darkhairedlord wrote:

using the same power on the flat as up hill is inefficient and your body knows this, so it is trying to slow you down

So if you can put out 300 watts at threshold on the flat, you shouldn't try to put out more than 200 watts or so when climbing? :?

BenderRodriguez

BenderRodriguez wrote:

Perhaps what is happening is that when climbing the torque is applied in a much more sustained manner, reducing the peak torque needed that way, but in turn demanding a lower cadence in comparison with riding on the flat when a high revving but 'punchier' pedalling style works best.

This does seem to make logical sense, as if you have a constant, high resistance to work against with a tendency to 'stall' if the pressure is eased off, as when riding up a hill, it seems to make sense that the best way to over come this resistance to to apply torque for as long as is possible during each revolution. Conversely, when there is a lot of momentum, one can simply keep giving a 'kick' of power, much like when giving a strong, sharp pull to spin up the fan on a Concept 2000 rower.

To return to this point, it could be that what is happening when climbing is not so much that the pedalling style is modified in order to better pass through the top and bottom 'dead spots' (there is evidence that this does not happen) but rather the torque profile is modified, shifting from a 'punchier' style best suited to a condition of high crank inertial load, to a more sustained one with a lower peak torque. If so then one would think that a study somewhere should have found that such a torque profile was bio-mechanically beneficial in some way. I think that this is exactly what the following study found.

Influence of pedaling technique on metabolic efficiency in elite cyclists. Biology of Sport, Vol. 29 No3, 2012 229. 3 Nov 2012.

ABSTRACT: Our objective was to investigate the influence of pedaling technique on gross efficiency (GE) at various exercise intensities in twelve elite cyclists ( ·VO2max=75.7 ± 6.2 mL·kg-1·min-1). Each cyclist completed a ·VO2max assessment, skinfold measurements, and an incremental test to determine their lactate threshold (LT) and onset of blood lactate accumulation (OBLA) values. The GE was determined during a three-phase incremental exercise test (below LT, at LT, and at OBLA). We did not find a significant relationship between pedaling technique and GE just below the LT. However, at the LT, there was a significant correlation between GE and mean torque and evenness of torque distribution (r=0.65 and r=0.66, respectively; p < 0.05). At OBLA, as the cadence frequency increased, the GE declined (r=-0.81, p < 0.05). These results suggest that exercise intensity plays an important role in the relationship between pedaling technique and GE.

http://www.biolsport.com/fulltxt.php?ICID=1003448‎

OK, this study did not specifically look at riding in a low crank inertia condition, but the implication that a more even torque distribution (with a more sustained but lower peak torque value) is associated with an increase in general efficiency suggests that a similar effect might apply when climbing at a slower cadence but with a more sustained application of torque.

It would also seem that the increase in GE found it this study may well be due to the reduction in peak torque allowing the recruitment of the minimal possible number of the more easily fatigued 'fast twitch' muscle fibres. Other studies have suggested that the raised cadence adopted when sustaining a high work load in a condition of high crank inertial load is because this also allows a reduction in the peak torque value. Given this, it would seem that the neuro-muscular system is probably geared towards generating the power needed in a away that maximises the use of the more fatige-resistant 'slow twitch' fibres, which would seem to make a lot of sense. Exactly how this is achieved depends on other factors such as the crank inertial load.

Stalin

An interesting discussion Bender is having with himself.

The neuromuscular system most definitely will use slow twitch muscle fibres first and saves the less efficient fast twitch fibres for as long as possible and only recruits the fast twitch when the forces reach a point where they are required or when the slow twitch fibres are exhausted.

250 watts at 100 rpm is totally different to 250 watts at 50 rpm. The technique is different, the recruitment if muscle fibres will be different, possibly due to a greater percentage of fast twitch fibres being recruited at 50 rpm oxygen consumption might be greater.

It is probable that your sustainable power may be higher or lower at the same wattage depending on the forces and rpm employed. It is probable that FTP on the flat at cadences between 90 and 100 rpm is different to FTP at 50 to 60 rpm up hill.

If you do the bulk of your training at or near FTP on a turbo at 90 to 100 rpm that you will improve your FTP at 90 to 100 rpm but find your FTP climbing at 50 to 60 rpm has not increased by the same margin if at all.

darkhairedlord

Could it just be that you hit the slope at 100-110 rpm then as you slow down your cadence falls. You change down a few times as speed reduces trying to keep the cadence up. Eventually you stop changing down in the hope you can hold onto the pace you have. We all do this to some extent, some consciously on subconsciously. Try getting a shrink to put you hypnosis next time your on climb to find out what your doing

Alex_Simmons/RST

Stalin wrote:

The neuromuscular system most definitely will use slow twitch muscle fibres first and saves the less efficient fast twitch fibres for as long as possible and only recruits the fast twitch when the forces reach a point where they are required or when the slow twitch fibres are exhausted.

250 watts at 100 rpm is totally different to 250 watts at 50 rpm. The technique is different, the recruitment if muscle fibres will be different, possibly due to a greater percentage of fast twitch fibres being recruited at 50 rpm oxygen consumption might be greater.

Yeah, it's tempting to think that. The problem is the majority of, but not all, studies addressing efficiency and cadence find lower cadences typically equate with higher efficiency, which would not make sense if low efficient fast twitch muscle fibres were being recruited to a significant degree.

There are however differences in the pedal torque profile when climbing versus flat riding but it's tricky to measure in the field and see what impact that might have on muscle fibre recruitment.

Stalin

Alex_Simmons/RST wrote:

Stalin wrote:

The neuromuscular system most definitely will use slow twitch muscle fibres first and saves the less efficient fast twitch fibres for as long as possible and only recruits the fast twitch when the forces reach a point where they are required or when the slow twitch fibres are exhausted.

250 watts at 100 rpm is totally different to 250 watts at 50 rpm. The technique is different, the recruitment if muscle fibres will be different, possibly due to a greater percentage of fast twitch fibres being recruited at 50 rpm oxygen consumption might be greater.

Yeah, it's tempting to think that. The problem is the majority of, but not all, studies addressing efficiency and cadence find lower cadences typically equate with higher efficiency, which would not make sense if low efficient fast twitch muscle fibres were being recruited to a significant degree.

There are however differences in the pedal torque profile when climbing versus flat riding but it's tricky to measure in the field and see what impact that might have on muscle fibre recruitment.

Yep. Possibly has something to do with turning the pedals twice as often which is the other side of the coin and most of the tests being done in a lab on a machine rather than outdoors going up a steep hill or riding on the flat.

We do know that oxygen consumption starts to increase dramatically as fast twitch muscle fibres start to be recruited significantly. We also know oxygen consumption increases as we exhaust the slow twitch fibres and recruit fast twitch even though power has not increased.

We also know the studies tend to be based on small sample groups, sometimes untrained individuals etc etc.

If muscle fibre recruitment has nothing to do with these differences what might it be?

Perhaps it is down to the fact lower rpm higher force requires a different technique to high rpm lower force at the same power?

BenderRodriguez

Alex_Simmons/RST wrote:

There are however differences in the pedal torque profile when climbing versus flat riding but it's tricky to measure in the field and see what impact that might have on muscle fibre recruitment.

In my view this is key, and although the 'all that matters is pushing down hard and beyond that pedalling technique is a red-herring' brigade have often denied it, I feel that there is evidence showing that, even if all the old ideas about 'pulling up', 'pedalling in circles' and so forth are mistaken, it does matter exactly how one presses down on the pedals.

There is some evidence that a more even torque distribution is more efficient, probably because it leads to the deployment of fewer 'fast twitch' fibres than a 'punchier' pedalling style that has a higher peak torque but less even torque distibution. For example, that paper I cited earlier which found that "at the LT, there was a significant correlation between GE and mean torque and evenness of torque distribution". This suggests that those who have argued that developing a 'smoother' pedalling style would be of benefit are, after all, correct.

This naturally leads onto the question of whether it is actually possible to develop a 'smoother' pedalling style with a more even torque distribution? I would argue that this is possible and that the differences between pedalling on the flat and on a climb show that almost all rides naturally modify their torque profile in response to external factors in any case.

I feel that what is happening, in both the case of hammering along at threshold on the flat in a time trial and riding up a climb at threshold, is that the neuro-muscular system is trying to minimise the peak torque value and, in turn, number of more fatigue-prone 'fast twitch' muscle fibres that are recruited in order to produce the required power. Given the high crank intertial load on the flat, the best way to do this is to raise the cadence whilst maintaining a relatively 'punchy' pedalling style. On a climb the low crank inertial load means that there is more to be gained from increasing the duration that the torque is applied for, one side effect of which is a somewhat reduced cadence.

BenderRodriguez

P.s. I have just read Obree's book, and whilst a lot of what he says doesn't make that much sense to me, as with the supposed benefits of 'flaring ones nostrils', I think that his view on pedalling correlate quite well to what I have been saying. For example, his view that one should take any flywheel off a one's turbo trainer so that one's neuro-muscular system has to learn to pass through the "dead spots", instead of being carried through by the flywheel effect. I know that Alex has argued exactly the opposite, but as I have said, this could be because Alex has just focused on riding in conditions where there is a high crank inertial load. Here is some of what Obree has to say about pedalling style"

Everybody who rides a bike knows how to pedal just the same as anybody who does not drown in deep water knows how to swim. The fundamental problem with pedalling is that the pedals bowl round and round whether you pedal in a good way or not and bad technique looks no different from good technique. I make the analogy to swimming again in this chapter because the complexity of pedalling with optimum efficiency is probably as complex and engaging as learning a good stroke from a bad one. In swimming, a poor technique would be instantly noticeable and correctable to the trained eye, and more to the point, the swimmer would be eager to improve technically since success would be impossible otherwise.

The amount of energy transferred to [the pedals] is simply the amount of force applied to it multiplied by the distance travelled. It is slightly more complicated than that because it is the force pushing the pedal forward that counts. What this means is that a smaller force applied to the pedal in a forward motion for a greater distance travelled can produce more energy than a large force for a shorter distance. In other words a rider with weaker muscles in terms of absolute strength can produce more power and more speed than a stronger rider if he uses more of the pedalling circle more effectively.

BenderRodriguez

Alex_Simmons/RST wrote:

The problem is the majority of, but not all, studies addressing efficiency and cadence find lower cadences typically equate with higher efficiency, which would not make sense if low efficient fast twitch muscle fibres were being recruited to a significant degree.

But don't these studies also show that the cadence / efficiency relationship is also closely related to power output? Hence, at relatively low power outputs it is more efficient to use a lower cadence as this reduces the bio-mechanical losses due to to imperfections in muscle coordination, joint losses and so forth, whilst the power output can still be sustained by recruiting predominantly 'slow twitch' fibres.

As power outputs rise and the number of 'fast twitch' fibres being recruited rises, so do blood lactate levels. Eventually, the 'cost' of recruiting these fibres outweighs the benefit to be had from minimising the bio-mechanical losses, so the neuro-muscular system instead raises the cadence, so reducing the peak torque values, albeit at the cost of a raised oxygen demand.

Stalin

Alex_Simmons/RST wrote:

Stalin wrote:

The neuromuscular system most definitely will use slow twitch muscle fibres first and saves the less efficient fast twitch fibres for as long as possible and only recruits the fast twitch when the forces reach a point where they are required or when the slow twitch fibres are exhausted.

250 watts at 100 rpm is totally different to 250 watts at 50 rpm. The technique is different, the recruitment if muscle fibres will be different, possibly due to a greater percentage of fast twitch fibres being recruited at 50 rpm oxygen consumption might be greater.

Yeah, it's tempting to think that. The problem is the majority of, but not all, studies addressing efficiency and cadence find lower cadences typically equate with higher efficiency, which would not make sense if low efficient fast twitch muscle fibres were being recruited to a significant degree.

There are however differences in the pedal torque profile when climbing versus flat riding but it's tricky to measure in the field and see what impact that might have on muscle fibre recruitment.

Because average effective pedal force is high, climbing using high force low cadence must significantly recruit fast twitch muscle fibres.

Studies show that functional threshold power tends to occur at the power and thus the force at which fast twitch muscle fibres begin to be significantly recruited.


If you do the bulk of your training and improve your FTP by doing the vast majority of your training at high cadence it is highly likely that this improvement may not transfer to improved FTP at low cadence.

It isn't just the power numbers, you need to look at how that power is produced and train accordingly.

BenderRodriguez

Stalin wrote:

If you do the bulk of your training and improve your FTP by doing the vast majority of your training at high cadence it is highly likely that this improvement may not transfer to improved FTP at low cadence. It isn't just the power numbers, you need to look at how that power is produced and train accordingly.

This is exactly what I have found after spending the winter significantly raising my FTP on the track, so much so that whilst previously I could only do a '2 x 20' at around 39 km/hr, my recent best averages out 43.8 km/hr. Despite this, I do not seem to have found much of an improvement in my average speeds, perceived intensity, onset of glycogen depletion and so forth when doing a long ride around my local mountains.

Effectively dismissing my experience as nothing more than an anecdote, Alex vigorously argued that 'FTP is FTP' and any increase will be apparent in all domains, including increased long-term endurance. When I pointed out that on his own blog Alex argues that whether your turbo has a flywheel or not can have very different training effect...

each scenario feels quite different to ride, muscle activation is different, the neuromuscular demands are different and these can be enough for some to make power production much harder

...Alex argued that whilst the metabolic adaptation would be the same, each case would product different neural adaptations, with re-modelling these neural adaptations being something that can be done relatively quickly. This might be true, but no research references were given to back up the claim.

Whatever, it does seem that you cannot expect training done under one set of conditions to fully transfer to another domain, even if 'only' neural adaptations are needed to see greater transference. How would such 'neural adaptations' be achieved? I would guess by actually training under the conditions set by the domain you wish to perform in! As the old saying goes 'SAID', 'Specific adaptation to imposed demands'.

Alex_Simmons/RST

BenderRodriguez wrote:

Effectively dismissing my experience as nothing more than an anecdote,

so my crime is pointing out that an anecdote is an anecdote.

my anecdote is my long duration climbing power was equivalent to my flat land power, despite not having any local long climbs to train on. It also improved at about the same rate as my trainer and flat land power did.

As for teasing out neuromuscular differences from metabolic ones, I suggest people use Quadrant Analysis as a first order means to gain some insight into that. Here's an example of looking at QA from threshold efforts on trainer versus outdoors:

http://alex-cycle.blogspot.com.au/2009/ ... lysis.html

I've always said one needs to consider specificity in training.

BenderRodriguez

Alex_Simmons/RST wrote:

I've always said one needs to consider specificity in training.

And yet when I said that raising my FTP on the track does not seem to have transferred as well as I had hoped to doing long, mountainous rides, you argued that:

I'm not saying that two riders with same FTP will have same long duration power ability, what I'm saying is the fundamental adaptations required to improve each are the same. IOW if you are training to improve your FTP, then you will also improve your long duration power / endurance.

Naturally there are other factors that do come into play for endurance (e.g. overall training loads which enhance endurance ability, able to sit on saddle for long durations, ability to ingest sufficient calories and fluids), but the most important physiological factors are those adaptations that underpin threshold power (and LT).

viewtopic.php?f=40011&t=12957414

Here you certainly seemed to be arguing that the most important factors underpinning endurance are 'general' and not specific.

In the same thread you also directed me to a study to illustrate the potency of neural as opposed to metabolic adaptation which showed that non-cyclists could produce more sprint power than competitive cyclists after just a few minutes high-intensity training over 2 days. So much for the benefits of specificity, in this case at least!

Perhaps the most important aspect of specificity is simply the promotion of activity-specific neural adaptation, with the 'metabolic' aspects being much more generalisable even to the extent that, for example, cross-country skiing could improve the 'metabolic' components of cycling performances to much the same degree as cycling itself?

Perhaps similar principles apply here as with much else in training, 'Specificity is important, except when it isn't'.

Stalin

Any info on rowing transferring to cycling?