Improving Running Economy

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Improving Running EconomyMarch 16, 2011 by Bill Henderson, MD 36 Comments

[While iRunFar rarely touches on the technical aspects of running fitness, we received an offerwe couldn't refuse from our good friend and exercise physiologist Dr. William Henderson of Endurance Science . In the following article he explains various ways that you can improve yourrunning economy. ]

In the previous article, I examined some of the science around footstrike patterns with respect toinjury, economy and speed. I think that it is fair to say that proponents of mid/forefoot runninghave a whole lotta splaining to do before objective observers will believe that it isintrinsically better than the more typical foot strike pattern. There are some useful ideas withinthe Chi/Pose models ideas like landing under the center of gravity. I dont want to give peoplethe impression that Im a technique nihilist and that I dont think that there is anything that canbe done with respect to technique to improve an athletes speed and economy.

For example, in this article Ill look at the evidence for several areas that I think that a runner canimprove technique. Namely, well look at the evidence for: i) foot contact time and cadence andii) plyometric and strength training ways to improve speed and economy without necessarilyincreasing fitness (yea, free speed!). High speed running, another method of improving runningeconomy is not covered in this article

As Ive said before, none of these ideas are secrets, and you dont need to buy expensive trainingcourses to learn, utilize or benefit from these strategies. As always, these techniques need to beadopted slowly, preferably under the supervision of an experienced and credentialed coach whocan evaluate you as an individual.

Improving Running Economy: Cadence and Contact Time

Do you ever watch other people running? It seems like some of them float along, barely touchingthe ground, while others seem to labor slowly forward, with excessive movement and heavy

footfalls. Think a bit about how the graceful ones look quick, light steps, no overstriding andno scuffing and scraping noises when their shoes contact the ground. They seem more efficientand it shouldnt be a surprise that they are. An exercise physiologist might call this economy.

Some of these attributes can be developed in an athlete by focusing on one thing runningcadence. Cadence is simply the rate at which leg turnover occurs (i.e., how many steps are takenper minute). If your left foot contacts the ground 70 times per minute, your cadence is 70.

Jack Daniels made the observation that the best athletes in any distance over about 2,000m runwith a cadence of about 90. No matter the speed, cadence stayed pretty much the same, onlystride length varied. Most beginning runners tend to run with cadences of 80/min or less.

Daniels suggests that quick cadence decreased injury by minimizing vertical oscillation (and,therefore, landing forces) and is more economical because it minimizes ground contact time
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GCT. GCT is the time that a runners foot spends on the ground with each step. As an athletesspeed increases GCT naturally decreases, but this can still vary between runners. A shorter GCTimplies that you are spending less time planted on the ground, but also the force generated byeach step occurs over a briefer period of time, which minimizes force absorption and dissipation.Daniels felt that we should all aim to run with a cadence of approximately 90/min, as this wasoptimally efficient.

I recently came across a great post by Roberto Veneziani on his excellent blog , wherein hecharted his cadence versus his Polar Running Index. The Polar Running Index is aproprietary measure that attempts to give you a global assessment of your running performanceduring any workout. Although the exact formula is not public knowledge, it isnt that difficult tofigure out. Basically, it calculates what your heart rate is as a percentage of your max HR (usedas a surrogate for VO2max) and measures your running speed at that HR. By normalizing yourspeed to heart rate, it can compare runs at different speeds. Simply put, it can tell you if you aregetting fitter/more economical over time, even if you are running at different speed and HRs. Itthus gives a global measure of fitness and running economy.

Roberto compared his cadence tohis running index over many runs and found that he got the best running index measures as hiscadence approached 90. This would seem to support Daniels empiric observation that this is thecadence for optimal performance in longer distance events.

Beyond GTC and decreased vertical oscillation, I wonder whether there might be biochemicalreasons why optimal running economy might happen around 90 strides/min. In a studyperformed in the early 1990s, eight cyclists were asked to pedal on two occasions at 85% of theirVO2max for 30 min. The first time, they used a bike gear that required a cadence of 50 rpm, andon the second occasion, a gear that required a cadence of 100 rpm.

With the slower cadence (i.e., higher resistance) pedaling Type II muscle fibers (fast twitch)used up glycogen 50% faster than during high cadence (lower resistance) pedaling. Type I fibers(slow twitch) used fat and glycogen at about the same rate at either cadence.

So why might this affect economy? At slow cadences, as type II fibers run out of glycogen, theyare less able to contract, forcing the recruitment of other muscle groups. This leads to: i)deterioration in form and ii) less efficient use of energy and oxygen. Both of these factors cancontribute to less effective cycling.
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Similarly, French scientists foundthat a 14 week program of heavy lower limb weight training, which occurred concurrently withendurance training improved running economy in 5km trials.

What is interesting about both of these studies (and shown in many similar studies) is that thisimprovement in running times occurred without an improvement in aerobic fitness as measuredby VO2max. We can therefore conclude that the improvements were due to better efficiency inrunning (i.e., running economy). This was presumably because weight training improved theeffectiveness of recruitment of the involved muscles or allowed the recruitment of stabilizingmuscles thereby improving stride efficiency.

During endurance training some runners find that their stride length shortened as compared towhen they are focusing on speed training. A group of Spanish researchers demonstrated thatweight training prevented runners from developing a marathon shuffle.

The trick for most of us is to actually find the time to add this type of work into our trainingregimen. I think that there are a few general rules that apply: start with small doses of weighttraining, begin in the off season, and dont become a weight lifter rather than a runner.

In the next section, I outline a strengthening program that combines the benefits of strength andplyometric training for endurance runners.

K Stkren, J Helgerud, E Stka, and J Hoff. Maximal Strength Training Improves RunningEconomy in Distance Runners. MSSE 2008G Millet, B Jaouen, F Borrani, and R Candau. Effects of concurrent endurance andstrength training on running economy and VO2 kinetics. MSSE 2002.J Esteve-Lanao, M Rhea, S Fleck, and A Lucia. Running Specific Periodized StrengthTraining Attenuates Loss of Stride Length during intense Endurance Running. JSCR2008.

Improving Running Economy: Jumps!In the previous section, I outlined some of the evidence for ancillary strength training for
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runners. I think that there is clear evidence that lower body strength exercises can improverunning economy (and, therefore, performance) in well trained runners. I received twointeresting emails related to this subject that I thought I would expand upon.

The first email asked if it was better to add weight training or more running volume to improveperformance. This is an excellent question, as it gets to the heart of many cross-training myths.Many people feel that they can cross train their way to better running. I think that cross trainingin other sports is very beneficial, particularly in that it can allow development of stabilizingmuscles, avoids developing the not 100% attractive runners physique, prevents burnout andis, well, fun! However, there is no doubt that the strongest predictor of distance runningimprovement is volume of running. So if you can increase your volume further (without injury orburnout), this is probably the way to go. But if you have hit the point where more volumeleads to injury, excessive recovery time, or if performance has plateaued, then adding non-running training seems prudent.

The second question asked about plyometric training. Plyometrics is a system of exercises thatuses rapid, explosive movements to improve power. Examples include hopping, bounding, box

jumps and so on. The mechanism by which plyometric training increases power is interesting.Rather than increasing muscle strength/mass, plyo exercises improve musculotendinous stiffness thereby improving the energy storage and energy return during resisted movements. Forexample, plyo box jumps will, over time, improve the efficiency with which the energy stored inthe tendon/muscle during landing is released. In a sense, it improves the spring action of themuscles and tendons. If you think back to my explanation about ground contact time, you can seethat a more powerful push off during running is beneficial. So whats the evidence?

There are several studies that show a link between plyometric training and improved runningperformance. The one I like best (because the scientific method was the most rigorous) waspublished in 2003 in the European Journal of Applied Physiology. In this study the authors foundthat a 4 month plyometric program improved running economy and 3km race time by 2.7%.

While 2.7% isnt a trivial improvement, I do have some concerns about most runners adoptingplyo training. Essentially, I think that this is a high risk tool. The rate of injuries doing plyotraining is relatively high, and I think that the most extreme drills box jumps, cone jumps, etc,are probably best done only by experienced athletes with coaching supervision. More traditionaldrills such as on-track hopping and bounding are probably reasonable if done carefully.However, I think that the large majority of the improvements in economy seen with these drills

can probably be achieved more safety with strength training

RW Spurrs, ML Watsford, AJ Murphy. The effect of plyometric training on distancerunning performance. Eur J Appl Physiol (2003) 89: 17.

Call for CommentsDo you incorporate any activities in your training specifically to enhance your runningeconomy? If so, what?

This article is way out there. There are no related articles on iRunFar.
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Filed under Resources , Training Tagged with plyometrics , running economy , strength training

Bill Henderson, MD a contributor to iRunFar.com.All posts by Bill Henderson, MD

Comments

36 Responses to Improving Running Economy

1. Dave says:March 16, 2011 at 6:35 am

I am a marathon runner, a part-time barefoot runner, and an engineer. I have experimentedwith running form over the last 2 years, and have migrated to a higher cadence, shorterstride, midfoot strike pattern. The engineer in me thinks about this whole topic as aconservation of energy problem. My running form is thus an emergent result of reducingwasted sound energy (run quieter) and eliminating unneeded body movements. I.e. reducevertical movements to minimize chemical (muscle) energy wasted to stop my downwardmomentum, and to accelerate upwards.

Your article is excellent, appropriately skeptical (in the scientific sense of the term), and Ibelieve correctly identifies that cadence, and not foot strike, is the key to efficiency. Iespecially am fascinated about the magic cadence of 90, and have long felt that there isan biochemical reason for this number. Perhaps this cadence allows the optimal refractiontime for a muscle fiber to reload and fire again? If so, it would make sense that humanswould evolve mechanically in a way to best take advantage of this biochemical efficiency,assuming you subscribe to Liebermans persistence hunting theories.

ReplyWilliam Henderson says:

March 16, 2011 at 10:53 amDave, Im never quite sure where to place the ancestral history models in science(i.e. paleo diet, persistence hunting, etc). They have a certain intuitive appeal I willagree. Differential fibre recruitment patterns have been widely looked at as a way of explaining variations in efficiency between groups of runners and cyclists. Onbalance, I think that it is fair to say that adopting a strategy that recruits relativelymore type I than type II fibres probably favours more sustained endurance efforts.

A related question, is can we change our fibre types? That is, will long years of training change type II fibres into type I? There is some evidence that this may betrue. Some very elite athletes have shown improvements in economy over years laterin their careers, and many believe this is due to fibre type changes (for example see
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Coyles paper on Lance Armstrong or Jones on Paula Radcliffe).

I agree with you, and many others that have posted on this and my previous articlethat cadence, foot strike, centre of gravity and shoe type all confound clear answersin this area.

Reply2. Aaron Harrell says:

March 16, 2011 at 8:51 am

Great article that seems to summarize a great deal of what I have been reading over the lastfew months. As a runner who is recovering from calf pain and is interested in injuryprevention, I have been looking at ways to create balance in my running form and strength.I have been running with minimalist shoes (five fingers, huaraches) and more traditionalrunning shoes for the last few years, so I have been interested in the information andconversations about how we prevent injuries and become more efficient. What I havenoticed is how there was much attention paid to foot strike at first, and then more recently

this focus has moved to cadence. What I like is that there seems to be some really greatinformation that indicates that all of these things are merely ways of indicating that arunner is maybe not running as efficiently as they could be.

All that to say, thank you for taking the time to compile a number of ideas and making thatinformation usable to people like me. I am interested in running injury free, thats really allI want. The more tools I have to do that, the better off I will be.

Reply3. Brett says:

March 16, 2011 at 10:02 am

Disclaimer I took statistics a looooooooong time ago. But doesnt an R^2 = 1 mean aperfect correlation, and the lower the value the worse the correlation? The reason I ask isthat in that first chart, the data seems to be all over the map and the R squared value isalmost 0.

ReplyWilliam Henderson says:March 16, 2011 at 10:46 am

Brett, it certainly does, and just eyeballing Robertos data will give you a similarimpression. His thoughts were really to illustrate his experience. Given the relativelysmall data set,it does look pretty spread out. Perhaps with a few hundred moresamples it would be clearer.

Reply MikeC says:March 16, 2011 at 11:04 am

Brett, I was thinking the same thing, I remember .1 as being a very low correlation.

Running light on your feet and a high cadence seem to go together to me. One
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begats another.

Ive always thought Jesse Owens had the most effortless stride. He claims his secretwas I let my feet spend as little time on the ground as possible. From the air, fastdown, and from the ground, fast up

Reply Andy says:March 16, 2011 at 7:21 pm

I also took stats a looong time ago (and Im a psychologist, not an exercisephysiologist), but I believe that an R-squared of .1139 is the amount of varianceaccounted for by the covariation of the two variables, which equals an R (theactual correlation coefficient) of about .34. While this may still not seem extremelyhigh, it fits with the pattern of data shown, and suggests a moderate relationshipbetween cadence and running performance. And it certainly fits with efficiencyand wattage output data in cycling, and with the experience of most of us running

light and fast.Great stuff. Now lets go put the science in action!

Reply Brett says:March 18, 2011 at 6:40 am

I looked it up, and R^2 = 1 is a perfect correlation. R^2 = -1 is a perfectinverse correlation. R^2 = 0 is no correlation. So looking at the data on the

plot visually and the R^2 both show there is no correlation.

I dont at all disagree with the thesis, but whatever data set that is, isworthless.

Reply4. Tyro says:

March 16, 2011 at 11:32 am

I thought the digs at Pose/Chi were a bit much in your last post but theyre becomingwilder and harder to ignore.

I think that it is fair to say that proponents of mid/forefoot running have a whole lottasplaining to do before objective observers will believe that it is intrinsically better thanthe more typical foot strike pattern.

We know that adopting a forefoot strike lets us run comfortably with no cushioning (ie:barefoot or minimalist) where a heel strike would have us crippled or crying in no time. Ithink thats pretty uncontroversial so I am still flabbergasted that you should imagine that

its the mid/forefoot group which needs splaining and not the heel strike group! Its also abitter irony that you should hold the forefoot strikers up to the fire when you yourself arecontent to make claims that are untested and unsupported but biologically plausible andconsider this good enough.
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Do you seriously believe that it is not biologically plausible that by adding cushioning (ie:shoes), the biomechanical shock absorption and injury prevention of a forefoot strikewhich works so well in barefeet will continue to provide more, not less, shock absorptionand injury protection over a heel strike?

After the last article, these posts are really feeling like a hatchet job and not the careful,unbiased look at the evidence that they purport to be.

Heres what Im seeing:

Pose/Chi: runners can improve their running (speed, efficiency, safety) by improving theirtechnique. This involves posture, foot strike, cadence, dorsiflexion, arm swing, reducedbounce, centre of gravity, leaning at the ankle and strength training. Here are some drillsyou can follow to make the transition. Depending on your time and money, here are somebooks, DVDs, clinics, and even private coaches.

William Henderson: studies show that after 2 months, PC runners have sore calves soyoure wrong, PC doesnt improve injuries

PC: we stress the need to develop slowly as modern shoes immobilize the foot and resultin atrophied calves and tendons. The benefits accrue over time, after your body hasadapted. Thats hardly a fair comparison.

WH: adjusting the centre of gravity led me to a faster cadence and become more efficient.That just shows what a load of hooey PC is.

PC: good posture and leaning forward to adjust the centre of gravity are core parts of what

we teach. How can you keep confirming our teachings only to say were wrong?WH: with fast cadence and adjusted centre of gravity, I run fine. In fact, I dont have a clueabout where my foot lands. Based on this N=1 study with no supporting evidence, Imeven more convinced that PC is bunk.

PC: Oh, if were letting in anecdotal evidence, heres a list of thousands of people who saytheir running has improved. Or we can go back to proper studies.

WH: heres a study which shows cadence improves running efficiency, so PC has a lot of

splaining to do!

PC: Again, cadence is a part of what we teach. Why do you keep presenting evidencewhich supports PC only to declare it wrong, are you really looking at the evidence or goingon the attack?

WH: running is simple, selling all these products is a scam.

PC: running *is* simple but if you wish to improve your technique we offer a range of products to suit your budget, including free materials on the web.

WH: running is too complex to learn from DVDs, you need a private coach! PC is still ascam.


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PC: But didnt you just say? Sigh, okay yes, we also offer private coaches.

Let me say that I do like to see what the studies have to say and its always interesting tohear how much of an effect various changes really can have. However these attacks againstthe Pose/Chi or forefoot crowd are really spoiling things. They show a dogmatic side thatmakes me think that you arent following the evidence but rather trying to beat down someviews you disagree with for reasons that arent clear to me.

As Ive said before, none of these ideas are secrets, and you dont need to buy expensivetraining courses to learn, utilize or benefit from these strategies. As always, thesetechniques need to be adopted slowly, preferably under the supervision of an experienced and credentialed coach who can evaluate you as an individual.

I touched on this above but those two sentences seem contradictory. If these techniques aredifficult enough that we need an experienced and credentialed coach (which costs money)but we dont have the money or no one is available, wouldnt a video course be effectiveand less expensive? Ive watched the Pose and Chi videos and they are really a series of drills and exercises that we can do to first ease the transition and secondly to perform someself-coaching which virtually all runners will have to do anyway as we dont have privatecoaches.

Again, this comes across as another wild attack on Pose/Chi: heads I win, tails you lose. If its something we can do on our own then you say their books and DVDs are a scam; if itssomething we need a coach for then even their in person seminars arent enough.

Why dont we just drop the attacks on Pose/Chi lest we start digging up the billions of dollars spend on insane shoe technology: pumps, aerogels, springs, coils, motion control,pronation control, memory foam, not to mention the billions spend on advertising shinydisposable shoes to consumers.

Reply Matt Smith says:March 16, 2011 at 12:57 pm

I think the point being made in both of Mr Hendersons articles is that the dogmaticassumption that Pose/Chi/Forefoot/Midfoot/Barefoot/Minimal is better in all cases isnot supported by the data.

Unfortunately, your vehement defense of the P/C dogma only makes the movementseem more like a cult than a revolution.

Minimal shoe proponents like Krupicka put a good face on the issue by using grass-roots engineering and fast running to back up their assumptions (and Anton is notwithout a history of injuries, most recently calf-related draw your own

conclusions) And then there are the barefoot wingnuts and POSE instructors whoturn the situation into a question of lifestyle and ethics (and commerce.)

Running is a big tent theres room for all types. And room for healthy skepticism
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of fad techniques and corporate shoe manufacturers, alike.

Reply Mark says:March 16, 2011 at 1:27 pm

Im not sure if Krupickas case is a good example to support or criticizePOSE/Chi standpoint. But, it brings up a good point. AKs technique/runningposture might be good for him (?). On the other hand, his numerous injuries,which are somehow correlated with huge mileage and minimalist shoes, makethe final answer more complex. It might be that the benefits of good techniqueare undermined by mileage/shoes factor. Obviously, mileage is one of the keyfactors in running economy discussion, and deeply affects posture and strengthissues. Something makes me think there is no one, correct, universal posture,but many due to: 1. Different physiologies, 2. Shoes, and, last but not least: 3.Distance. And more factors

Reply William Henderson says:March 16, 2011 at 2:58 pm

Nicely put!

ReplyTyro says:March 16, 2011 at 2:16 pm

Matt,

(Im gonna assume you arent THE Matt Smith or Id be too giddy to type!)

I think the point being made in both of Mr Hendersons articles is that thedogmatic assumption that Pose/Chi/Forefoot/Midfoot/Barefoot/Minimal isbetter in all cases is not supported by the data.

Why do you call them dogmatic? Theres plenty of evidence and, asWilliam says, biological plausibility for their claims so why do you call themassumptions? Ive asked William for specifics and he refuses, so would youplease provide some examples?

If this is just some inflamed rhetoric meant to jab at me, well okay but it seemsstrange to go over the top while complaining about how others go over the top.

Unfortunately, your vehement defense of the P/C dogma only makes themovement seem more like a cult than a revolution.

I am using evidence and reason to try do learn whats true and to defendevidence-based ideas that were attacked using innuendo and double-speak. If you look, William both attacked P/C for simultaneously providing too manymaterials to help runners and not providing enough.
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As for being vehement, I think I have a reason. Lets not forget youre callingyour opponents dogmatic cultists which some might consider to be vehement:) Maybe we can stick to specifics and leave the jabs on the side.

And then there are the barefoot wingnuts and POSE instructors who turn thesituation into a question of lifestyle and ethics (and commerce.)

Certainly I think that barefoot running is too extreme I see little advantage ingoing barefoot over having the right shoes and lots of disadvantages. I am alsobothered by the way that some barefoot proponents will try to bury the costs ormake them seem like features (eg: acting like the likelihood of bruises orgashes when stepping on rocks is a *good* thing because it forces you to bemore aware of your surroundings).

But I dont see how some weirdos in the POSE groups should undermine thePOSE system as a whole or undermine their claims. Its like judging a blogbased on the commenters.

ReplyWilliam Henderson says:March 16, 2011 at 1:13 pm

Hi Tyro, this is obviously an issue close to your heart and I think that you havecontributed a great deal here. I hope that we can all avoid ad hominem or personalattacks in this discussion. They dont elevate the conversation in any way.

I think that I have repeatedly stated that the ideas behind Chi/Pose, etc are not

unreasonable but that the claims made are well in advance of the evidence (at least inthe scientific literature). Its quite possible that one day Chi/Pose, etc will beproven scientifically. The same can be said of heel-strikinng or whatever youwant to call the dominant paradigm. My principal beef is their (Well really Pose)message that it already is (particularly from Romanov et al). Do I hope we can find away that is better to run? Of course. However I am skeptical that one style will workfor everyone (as repeatedly stated). As you can tell from the comments from manyhere, not eveyone share my opinion (or yours for that matter).

I fully agree with your thoughts about marketing, shoe over design and thesometimes nauseating crappification/accessorization of athletic performance ingeneral. Again, I think I alluded to this pretty clearly.

Do you have comments youd like to make about strength training and economy?


William,I dont have any investment into Chi or Pose but I do get irked by doublestandards and fallacious attacks. Call it SIWOTI syndrome if you like. You
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say youd like to do without the personal attack which is fine since thats whatI was protesting in the first place. Good for the goose & what not.

You say the claims made are well in advance of the evidence. Whichclaims? I went through your two posts and found all the references to Chi/Posethat I could and I couldnt find a single case where they said anythingdeserving of the scorn you heap upon them and in many cases your ownevidence vindicates them (yet you still dump on them). Where is this angercoming from? Specifically which claims are you addressing?

However I am skeptical that one style will work for everyone (as repeatedlystated)

Really? Why bother studying questions of technique and form if you dontthink that there were answers which are broadly applicable?

For instance, do you really imagine that having a cadence of 180bpm will be just as effective as, say, 30bpm? I doubt it, not after this long discussion of theevidence and advantages. Clearly you act as if one style will work foreveryone which is a good thing.


Hi Tyro, I think its a bit unfair so suggest Im refusing to answeryour questions. Lets try to stay civil. To get a sense of what I cionsider

the unfouned claims of the commercial proponents of POSE (and muchless so Chi) look at the home page of the posetech site. In very bigletters are their claims:

1) Prevent overuse injuries2) Move faster with less effort3) Unlock your natural potential (??)4) Get better resultsLook at the ChiRunning site:

1)Eliminate the cause of injuries2)Transform injuries in to wisdom (cool, I have lots of injuries and notmuch wisdom)3) Run faster4) Speed without injury

If you and I were running together and you said that these methods hadmade you faster and less injured, I would say wow, maybe Ill try it. If you opened a commercial site, charged $$$ and used the veneer of

science to gull the credulous I would say data please.Once again, I dont doubt that these styles may be good for somepeople, I encourage people to try them if there is a problem currently


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with their running (specifically knee/hip injury) and I fully accept thatthe science may one day reveal them as truth. For now, their strongclaims seem just that claims.

Reply Matt Smith says:March 16, 2011 at 3:51 pm

Well, that about sums it up.


William,

I would say that the Pose site makes more claims than this andthey have a pace thats dedicated to running in particular but okay.Again I have to ask: which of these claims do you dispute?

Faster? Youve presented evidence that cadence (a key factor of Pose and Chi) will make you more efficient and faster so letsconsider this claim to be supported.

Better results? See faster.

Reduce injury? Again, youve agreed that the emphasis on better

posture, striking closer to centre of gravity, and faster cadencewill reduce impact force and this is likely to reduce injury. I thinkwe both agree that Pose/Chi can be run barefoot comfortablywhich should be another big confirmation.

Learn from injuries? I think you (or your sources, I forget) saidthat P/C shifts stresses away from you knees and hip which are thecommon sources of injury to many runners.

The claims that seem unsupported would be the Chi in Chi

Running and the natural potential of Pose the claims I thinkwe both agree are the most nebulous to begin with.

Again, Ive asked for which claims you dispute and instead you just dump all their claims without saying which you have aproblem with. Well, which is it?

If you opened a commercial site, charged $$$ and used the veneerof science to gull the credulous I would say data please.

It sounds like youve decided theyre peddling bunk and thattheres no reason to buy anything they offer. Why? I think theyare offering things of value and their claims appear reasonable. As


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youve said before, this technique of running has a high degree of plausibility and youve presented studies which support elementsof their teaching, yet youre acting like theyre selling purehokum. All of this is a bit rich since you then go on to say thatyou dont doubt this will help some people!

What would make you happy? You talk about running coaches soyoure happy with people charging and spending money toimprove techniques. Pose and Chi offer a lot of free materials andthey offer inexpensive books to suit your budget. The arentselling Power Band magic bracelets which have no plausibilityand a wildly inflated costs, theyre selling a service at areasonable, market rate. Why are you hating on them so much?


Tyro, heres an excert from the POSE site:

There is nothing natural about heel striking way of running, as a matter of fact heel striking alone is responsible for countless seriouslyinjuredrunners pro, amateur, everyone. I bet you anything thatevery runner youknow is or was injured.

Interestingly, there is not a single scientific study that statesthatheel striking is good or bad for you. Strangely enough, allthe scientificstudies carried out on running were at best simplydescriptive withcollected data, but nothing definitive was ever pronounced.That is until

recently.The only scientific proof that exists in the world of runningtoday belongsto the Pose Method of Running.

The one study they reference is the one about loweredforces throughthe knee. There was no evidence in that study that it actuallydecreased knee injuries (sure it might, who knows). Theyneglect to mention the same studyshowed increased forces in the ankle (which the actualresearch subjects


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say was associated with injury).

There are other studies that look at POSE too. The runningeconomy one isnot mentioned on their site (despite being done at the sameresearchfacility I think). This study showed worse economy, soinfact contradictstheir claim that POSE makes you run faster, or at leastfaster at the sameenergy cost.

So they are sort of right that POSE has science around it,but not rightin how they interpret it, and disingenious/dishonest instating that the sciencesupports their claims. Does that specifically enough answer

your contention that I wont tell what I disagree with there?I also feel I need to address your specific attacks against mewith respectto having an agenda. I do. I have stated that I believeproponents of thisstyle have deliberately used the claim that Science provestheir methods superiority. This is a foundational part of their advertizing. When youlook at the data they actually quote though, it doesnt saywhat they sayit does. And there is data they dont admit the existence of that directlyrefutes their contention.

The fact that I think their ideas are plausible doesnt mean Iagree thatthey are proven. The fact that I believe that it may helpsome people is a reflection of my belief that studies cant

capture every individualsexperience (reductionism vs holism as Ryan referred to).They have put themselves out as scientifically proven to bebetter, and I say the science they quote and much theydoesnt say that and may say the opposite.

Tyro says:March 16, 2011 at 10:02 pm

William,

Thank you for the detailed reply.

The one study they reference is the one about lowered
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forces through the knee. There was no evidence in that study that it actually decreased knee injuries (sure it might,who knows). They neglect to mention the same studyshowed increased forces in the ankle (which the actualresearch subjects say was associated with injury).

Reducing knee injury would be a significant benefit formany people as it is a common, serious running-relatedinjury. In my limited experience, knee pains has been thesingle common issue raised whenever I hear someoneexplain why they gave up running and while anecdotal, it isstill a long-lasting, damaging injury. So if were being fairand they can reduce knee stresses and injury, I think weshould chalk this up as a huge win in their favour.

Youre right that if were swapping one serious injury foranother, we may not have gained much but is this whats

happening? I dont have the study in front of me but basedon what youve presented, they were very short term andwere reporting injuries which could be expected to improvewith time and strength. Was this one of those or do youthink ankle injury is inherent in their running style?

Again, Id like to set aside their advertising hype and lookat what the methods actually do.

This study showed worse economy, so infact contradictstheir claim that POSE makes you run faster, or at least

faster at the same energy cost.

That would be very interesting and I agree, it wouldundermine many of their claims. Can you share moredetails? Ive seen a couple which measure the heart rateshortly after transitioning and it is higher for runs at thesame speed. One argument is that the runner is adapting tothe higher cadence and the heart rate will adapt over a few

months time so I didnt think this was a very appropriatemeasurement. That was in part why I mentioned that Idlike to see studies with a longer time frame.

5. solarweasel says:March 16, 2011 at 12:49 pm

I always find these studies fascinating, but I feel that observing a performanceimprovement at particularly short distance due to some training technique and applying theresult to endurance athletes collectively is misleading. I dont think I need to illustrate thedifference between running a mile, a marathon, and a hundred.

Although I wish more studies of ultramarathon runners existed, I guess still comprise sucha small number that it would be hard for any researcher to justify
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Yes, generalizability is one of the one of the big issues with every single study in thefield. How well do examinations of technique, impacts, economy, speed done over amile or 5km translate to loooong distances? Additionally, do experiments using 25yr olds with a VO2max of 70 mean much for 40-60 year olds with VO2max of 48?What if you are wearing a backpack? Running on variable terrain as opposed to atrack or treadmill?

All unknown factors. Still, we can only argue from the available evidence. Id loveto see some of these studies done in long distance enviroments, but as you say,numbers are small and logistics difficult.

Reply6. jacob rydman says:

March 16, 2011 at 12:57 pmgreat stuff bryon. i dont do specific plyo workouts anymore, but what i mainly dothroughout the week are repeats on k2 (which is a mile long and climbs 1000 ! ). i feel like aclimb at this gradient (it averages 19%, with three or four pitches at 25% or above) withthe demands it puts on the ankle lever, calf, and achilles is like doing an informal plyoworkout and i have seen the benefits in terms of strength building and power. thewilderness is a great gym to get weight-room-like benefits. thanks for the great articlebryon.

Reply7. Alex from New Haven says:

March 16, 2011 at 3:44 pm

One thing I wanted to address was the myth of the 180 cadence:

Please read this article that addresses what different athletes do at different speeds. Whenathletes change speed, some change cadence, others stride length, others both.

http://www.scienceofrunning.com/2010/11/speed-stride-length-x-stride-frequency.html

There is NOTHING magic about 180. WR holder Bekele cruises at 190 and then, during alast lap acceleration cranks it up to 215 at the end of a 5 or 10k.

180 is an easy to number keep track of: 30 right steps in 20 seconds. But our idealbiomechanics dont know or care about our idiosyncratic base-60 way of keeping time.Maybe one person is most efficient at 187 at marathon pace while another is best at 193 at5k pace.

If youve ever seen (and heard) a non-runner clomp and smash away on the treadmill at150 strides/min you know instinctively that it is BAD and that their joints would behappier at a higher cadence.
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Sorry for the rant, but the myth of 180 needs to end. Its an easy number to keep track of and is a good cruise pace rule of thumb. Its not religion.

alex


Alex, you are obviously right that the actual number(180/90) isnt magic. Danielspoint (I imagine, never having spoken to him), and mine is, is that many peoplebenefit from a higher cadence. This might be 175 for you, or 187 or something else.I think that for a majority of beginning distance runners, especially those that dontcome from a track/middle distance background, their economy will improve byincreasing running cadence and as tyou say, 180/90 is an easy number to keep trackof and I think most people recognize this. There are many experienced runners herethat wont particularly benefit from this advice, but many who are less advanced and

might. I speculate that for all of us there is some individual cadence where we aremost efficient for a given power output. The cycling data presents a theoreticrationale for this empiric observation.

With respect to your example of Bekele (and I am sure you already know this, I justthink its interesting to think about), I would guess that when he cranks it up for thelast lap, he is becoming very inefficient. This doesnt mean that his velocity doesntincrease (obviously it does) but the the energetic work done increases more rapidlythan work (i.e. speed) does (ergo less efficient). For that kick, he is almost certainlyrecruiting more of the less efficient type II fibres (glycolytic rather than aerobicenergy) as well as generating a significant amount of work anaerobically, which isvery inefficient. He can afford to do this for the last lap because the consequences(O2 deficit, increased acidosis) will only become an issue once he ha finished.

Reply Alex from New Haven says:March 16, 2011 at 5:43 pm

You point about last lap possibly being lower efficiency is totally fair. For

example: Elite sprinters (100/200) have cadences up towards 300, but theycould care less what their efficiency is since theyre totally anaerobic and onlycare about power output and efficient transfer of power to the ground.

My chip is about the 180 meme that gets repeated and cited as if it were thegravitational constant or the conversion from feet to meters. I just feel that oursociety struggles so much with scientific literacy and are so overwhelmed withinformation that when someone in authority says This is the answer theydont know if its a fact, theory, estimate or rule of thumb.

sorry again for excess zeal. I enjoyed your post and think its great that itsgetting people to think about form and other things to improve their running.Cheers, Alx


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My apologies to All for the spelling and weird grammar. Ive been typing on a tablet orBlackberry All day as I sit doing ano experiment (hypoxia and bloodpressure)

Reply11. Roope says:

March 22, 2011 at 1:35 am

Good discussions on here, nice change of pace considering its on the internet :D

What intrests me is that.. If strength training increases economy by way of musclerecruitment and neurological adaptations, wouldnt flat out,40-60m sprints uphill kindof go for the same thing? just maybe more specific?

Also what are the more common injuries related to doing plyos?

ReplyWilliam Henderson says:March 22, 2011 at 10:55 am

Hi Roope, uphill running may give you many of the same benefits, not sure that theyneed to be flat out. Rememer that this will add to the load from which you need torecover

ReplyPaul says:November 14, 2011 at 7:19 am

Lydiard, the grandaddy of running long was dead keen on bouncing up hills. Worthchecking out if working out in a gym isnt your cup of tea.

Reply

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Improving Running Economy

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