Leg Speed - Page 2

?? I've done 280 rpm on a bike erg, but power was only 50 watts, obviously
I can't generate any kind of force at that rpm. When sprinting I feel that 125-130 is about the best at peak speed. I don't do track events but road races and TT's but I like to sprint now and then. In my case and and in everyone's case, higher power must be achieved by higher force production since anybody can move their legs at 140 rpm (which is typical max rpm in a sprint event).

-bikeguy

I need to dig back through some of my notes and readings. I think (potentially) there are two: fiber type conversion and contractile rates. How trainable each is I don't know.

I am curious about that very same question. The goal or idea anyway, would be to get the muscles to contract faster consistently, under a load that increases. Intuitively, I would guess, and it isn't much more than that right now, that there is some correlation between this ability and one's mix of type I & type IIa/b fibers.

To that effect, I found a post of Andy's on FGF about muscle type where there is some mention of rate of muscle contraction:

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All types of physical training (i.e., endurance, sprint, resistance) result in at least partial, and often nearly complete, conversion of type IIb (IIx) fibers into type IIa. Consequently, even sprint athletes will tend to have a lower-than-normal percentage of type IIb (IIx) fibers compared to untrained persons (e.g., ~10% vs. ~25%, depending on course on the particular muscle and just how sedentary the control subjects really are), and highly endurance trained individuals will often have few, if any, type IIb (IIx) fibers (generally <5% even in a mixed muscle such as the quadriceps). It remains controversial, however, whether it is possible to cause conversion of type IIa into type I - the genetic "machinery" is obviously there, and animal studies using chronic electrical stimulation for 8+ h/d have clearly shown such inter-conversion to occur. On the other hand, it hasn't been possible to obtain definitive proof of such fiber type conversion as a result of training in humans, although there is plenty of evidence (e.g., presence of fibers expressing both type IIa and type I myosin) suggesting that it does occur to at least a limited extent. My personal interpretation of the literature with respect to this question is therefore that the fast-vs-slow phenotype is one of the least "plastic" of muscle properties, and as such requires a very large stimulus to cause even relatively small changes.

Finally, note that while human fibers are "typed" based on the myosin isoform that they express, this is not the only factor that determine the speed of contraction/relaxation of a muscle. Specifically, even with endurance training type I, or slow-twitch, fibers tend to become faster contracting, whereas type II, or fast-twitch, fibers tend to become slower contracting, irrespective of any change in myosin. Thus, with respect to your real question - i.e., what changes in my muscles account for the changes in my performance as I've transitioned from road to track? - what happens to fiber type as it is formally defined really doesn't matter. That is, if the force-velocity properties of your muscleS have changed (and they almost certainly have), then you have effectively become more "fast twitch like", regardless of what a muscle biopsy might show.

One more section:

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The answer to that question is that the mechanical 'machinery' of muscle is composed of numerous proteins, and while the primary (well, along with actin) protein, i.e., may remain the same, others (e.g., the myosin light chains) do "switch" as a result of training, thus modifying the fiber's maximum speed of contraction. There are also changes in calcium handling (i.e., the rate at which it is pumped back into the SR) that influence the speed of relaxation, and hence how quickly you can repeatedly turn force production on and off. These changes, of course, are in addition to changes in the pathways of ATP provision, although the effects of sprint training here are far, far less than the effects of endurance training (which can result in up to a doubling of mitochondrial respiratory capacity, and equalization of this pathway in type II and type I fibers).

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(Emphasis added) - so perhaps there aren't studies but the point is to make one's muscles behave more like FT regardless of their original content?

Also, is this question of 'leg speed' improvement an old-school belief ala SE training or does it have some validity? Yes I know many people do it, but is there something other than experience and tradition to show that it works?

Weight training of an explosive nature combined with plyometrics (hops, bounds, depth jumps) is the best way to achieve these goals. The overload achieved in terms of sustained force production during a near max squat, deadlift or powerclean is cannot be duplicated by any other activities, not to mention the hypertrophy that increases available ATP and CP stores.
Plyometrics provide (i.e, forced eccentric extremely short, high speed contraction against a very large force, combined with a positive phase) a unique overload to the neural system and train muscles to fire "fast". Do that by doing double legged and single legged hops and depth jumps with an immediate rebound out. If you don't know what a "depth jump" is, then use google and the internet or find a book about them in a library.

No. Everybody even pure slow twitchers can spin at 160 rpm, the most you'll need to hit 65-70 kph+ on 50x15 or higher gearing. Really the main reason a person can't ride at say 65 kph is because the stores of ATP and CP are depleted in the acceleration so that there's no energy left to ride at 50,60, or higher kph.

There are four ways to get faster for sprinting: increase the pool of fast high energy stores (ATP and CP) or increase the mechanical efficiency of the working muscles. The third way that doesn't involve muscles is reducing frontal area or drag coefficienct (a very worthwhile area to look into as well ;-) . 4th is to reduce the mass of the system, hopefully without sacrificing power.

It's theorized that plyometrics increase muscle contraction efficiency through (among others) increased utilization of stored elastic energy and more synchronous muscle fiber firing. There are many studies that show increased peak power and speed after plyometric training. It's known that hypertrophy from weight lifting increases total CP and ATP muscle stores.

So thats my suggestion: lift weights and hop like a bunny.

I must be bored today, it's raining hard out and I can't ride. Wah.

Have a nice day,
-bikeguy

Yeah as a kid me and a mate used to easily top 230rpm on the ergs at the gym with no resistance. Former AIS sprint coach Gary West would drop the chain off the sprint bikes and guys like Neiwand and Hill could hit 300rpm. My mate was a sprinter and I was an enduro and I could outspin him. He could just waste me when the top end power was needed so I would read too much into it.

Hamish Ferguson
Cycling Coach

I do leg speed training 2 times a week even though I already have a naturally fast cadence on the road (95 to 104). I believe that this trains the brain and legs to have to peddle smoother(less bounce on saddle) at high cadences. LIke anything else with cycling-its a skills training and this is the best time of the year to train. Theres also no reason to not combine them within other training rides because they are usually done in Z2 or Z3 in a light gear so not very taxing. I used to start bouncing in the saddle at 114 rpm and now can pedal pretty smoothly at 122.

I didnt know hitting 200 wasnt possible for everyone. I thought it was something that could be trained. My first attempt I hit 180 and the second attempt I hit 193 and held it for about 5 seconds and then legs tightened up. This was of course on a stationary trainer in a light gear. I"ll never hit 200 rpm on a raod sprint (No tracks close to me), but I figure if I can train myseklf to spin over 200, it should improve my ability to hit 150 in a sprint which I see as doable and an advantage in racing.

I think one's fiber mix is pretty much genetically determined, and not really trainable. Strength training to produce hypertrophy increases the size of individual fibers, but still doesn't significantly change the number of fibers or the type distribution.

I was thinking about this further during a quiet moment, and I think Alex's comments really illuminated something for me (thanks, Alex). Certainly one can increase their peak cadence through technique, but cadence only limits speed when one doesn't have multiple gears to choose from (ie, a higher peak cadence doesn't really produce a sprint performance improvement for roadies). What benefits a roadie is high power produced at sprint speeds, which means higher *force* being produced at the cadences typically used during sprints (120-130 rpm, not 170-200). IOW, since neuromuscular adaptations are specific to joint angles and velocities, the goal of sprint training is to improve the force being produced at the velocity (cadence) which will be used during the event. For some reason, Alex's comments about increasing gearing only after one is able to spin out the current gear is what finally brought this to light for me, and now downhill sprinting, motorpacing, and all the other ways to artificially increase sprint workout speed seem to make more sense. It's rather pointless to develop NM adaptations which aren't specific the conditions present during targetted events. Now I'm not sure what benefit standing starts, low-speed jumps, stomps, etc. would be to a roadie, except maybe to yield 5-sec power values for plugging into their power profile.

Dare I say it? Leg speed is a red herring (for roadies, at least).

(Lucy, thanks for digging up those posts from FGF -- good stuff )

But, let's say that my peak power (pre-training) is produced at 120rpm. Is it possible through sprint training at higher cadences that I can both increase my peak power cadence to, say, 130rpm and increase my peak power (because my peak power was torque limited)?

For roadies, I think it still has a place. Legspeed helps in the changes of pace required in mass start racing. In training, having the ability to spin smoothly at ultra-high cadences may improve spin at regular cadences. Of course this needs to be proven.

But in designing programs with 2 months of indoor trainer time, every workout is not a intensity workout. Adding legspeed work without reducing resistance (doing legspeed +100% FT) really helps break things up and helps bridge power work to a functional sprint or jump capability.

Frenchy.....After reading the now famous AIS strength coach post at FGF, I've given it some thought and am seeing some definite correlation to on-bike training.

This is of course, a little n=1 commentary

Specifically, it was mentioned that there was a strength, power, and speed phase. For me, standing starts done uphill from virtually a standstill, are essentially the strength phase. Nowhere else can I generate as much torque, which makes sense given that I'm starting from a virtually zero cadence. While I used to do these primarly for max power numbers, now I focus more on doing them for strength. Now I can regularly hit 700+ lb-in in sprints.

Right, but what use is any of this to a roadie? Hmmm, well if your sprint is force/torque limited but leg speed is good, then standing starts might be the best thing. Unless of course, you'd rather go to a gym and lift and work on that limitation there. Then too, there is technique in a good standing start which might help people make their jumps and out of the saddle efforts more successful - whether in a sprint or an attack.

I think of lead-out and rolling sprints as more of a power phase, since cadence is higher, and thus, torque is lower. My maximal figures are now reached in these since I'm obviously more limited by leg speed than force.

It seems to me, at least in terms of what I read in this forum, that sprints are not just low-priority for many folks, but even completely ignored by some. Yes, road races are almost entirely aerobic so that should be the highest priority, however doing some sprints and learning a little technique can yield some real improvement, it doesn't take much time at all, and at least for me, is fun and breaks up the monotony of Level 4 work.

Plus, I mean really, you don't want to lose a sprint to climber types at the end of a hard-fought mountain stage do ya?

I've seen a 200+ watt increase in just one month

P.S. Stop the press! I absolutely flew by 2 riders yesterday while doing L4 intervals on a long hill. What is the world coming to?

Well, I'd rather be in one too small a gear and spin it out seated to 160 rpm than be in too big a gear, hit a wall and trudge to the finish line out of the saddle.

But-I am not a sprinter-so this is why I try to play to what I think my strengths are, which is leg speed over explosive power.

But-yeah-after reading this I was doing plyometrics while walking around the block with my 4 yr old daughter on my shoulders. HOpefully I'll have a sprint this summer!!

Ray

I dont know if this info will help anyone, but I looked at my PT file and it was 193 cadence for 10 seconds at 400 watts ave and 423 watts max. I did it in a 39/21 on a windtrainer. It will be interesting the next time if I can do it on a fluid trainer (it has more resistance) and hit 200 rpm. Maybe I'll have to do it in a 23.


But-as far as I know-theres no such thing as MAX cadence training!

As is mine, certainly -- just some musings from many, many hours behind the wheel this weekend. Glad we're on the same page.

But my point is that if we're hoping for neuromuscular adaptations (as opposed to hypertrophy -- remember we're talking about roadies), then those adaptations are specific to the joint angles and velocities achieved in training. I'm not sure there's any reason to believe that improvements in standing start torque are going to translate to higher torques at 120-130rpm (although standing starts themselves are very important to trackies, which would justify their use in my mind).

I've agreed that the potential for technique improvements is great.

I'm not sure that I understand what those bolded statements mean. Our muscles are capable of generating very large forces, or very high speeds, but not necessarily both at the same time. In any case, the peak power will never be generated anywhere near the limit of either force, or velocity, for our muscles. Assuming we all have a linear force v. velocity envelope like the one represented by the black sloping line here, mathematically the peak power will be generated near the middle of that line (ie, in the mid-ranges for both force and velocity, and not close to either limit).

I suppose we could propose improving our power through force work to try to raise the y-intercept, and then speed work to push out the x-intercept, but since the majority of the desired adaptations are neuromuscular, why not just train at the specific 'peak power' velocities and try to push the whole envelope out from the middle? Again, this is a luxury exclusive to roadies because of the ability to select sprint cadences through gear choice, and the fact that the bike does not need to be accelerated from a standing start or track-stand.


I agree completely. Let me just say that I do not claim to *know* what I'm talking about here, nor am I trying to argue anything -- this is mostly an academic exercise for me (although I may start to take a greater interest is the weather will cooperate for a bit). If others feel they have answers, please chime in or correct me. Most of my L7 work last year was low-speed jumps, but I'm now wondering if a change of approach is in order.

Pfft.... if it comes down to a sprint, then it wasn't fought hard enough.

Besides, I always let the early overpasses wear them down, and save my biggest kick for the *final* overpass.

Andy Coggan put an interesting presentation on fixed gear fever site and on of the examples given that for a 4000m pursuit the biggest gains would come from improving ones aerobic ability. Improving alactic had negligible impact on 4km times. So I presume it's even less important for crits or road racing.

Something I have noticed from the last year of racing and training with power is that while my peak power is 1200watts I have never come within 200watts of this in any road race. Tells me I should be improving my aerobic to get to the sprint in better shape. Now it's our track season I don't think this emphasis will change much.

Uh-huh, improving sprinting and neuromuscular power is negligible in a pursuit so why even bother working on it as a road racer?

No doubt our posters have big races to compete in and sprints only matter in token races like the ones below won by a bunch of no-names...