Last Updated on April 26, 2015 by Jimson Lee
There’s a reason why the October Issue of Men’s Health is pictured below. (Thanks to Divinio A. for pointing it out)
Here is a snippet of the article on page 36 referring to Leaning Power:
“Dig, dig, dig!” may not be the best advice to shout at a sprinter. A recent German study found that the keys to acceleration are forward lean and longer contact between your foot and the ground, not applying more force to the ground. Plant your foot farther than usual behind your center of mass for greater lean – this helps propel you at toe-off, the researchers say.
In short, they are saying the 2 secrets to sprinting faster are the forward lean and longer ground contact. The forward lean is referring to shin angles.
Hmm, longer ground contact?
The Ground Contact Debate
Sprinters worry about stride length and stride frequency. Heck, even Dwain Chambers thinks he can beat Usain Bolt based on these two parameters.
Ralph Mann’s research advocated reducing ground contact time as the only way to improve speed (all other variables constant).
Going back to basics, Bud Winter’s book So You Want to be a Sprinter mentions 3 ways to win a 100m race against Usain Bolt or a 400m against Jeremy Wariner. (It’s on page 14 for those who own it) The first 2 were mentioned above:
- Stride Length
- Stride Frequency
- Speed Endurance*
*This was the reason I chose SpeedEndurance for my Blog name, because I felt it was the least appreciated training aspect back in 2001 when I registered the domain name. As a 400m sprinter, I didn’t worry about my start because I could gain a lot more by improving my speed endurance. Same for the 200m, and to some extent, the 100m.
Bud Winter, who I felt was way ahead of his time, always advocated the forward lean and a strong push off (see page 14 of his book).
In his book, he lists 8 essential points to good sprint form (see page 23), with 8 accompanying drills to enforce those points. The forward lean is #5 on that list. If you don’t already own a copy, you can order it here.
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More on Shin Angles
In the BBC video where Michael Johnson explains Usain Bolt’s speed, he repeats the “shin angle” line several times. Like a lot of ex-world class athletes, MJ is now a coach.
The best example of shin angles and power is pushing a car stuck in the snow (for those who have to deal with snow). Note how a lower body, spine, and shin angle will be more effective than being upright. A simple drawing of physics and force vectors will show you 2 forces (actually 3): Horizontal and Vertical displacements. There is a 3rd force and that is gravity, which is constant for everyone.
Speed is the Result of Net Forces Acting on the Ground
To quote from the late Charlie Francis, who passed away on May 12, 2010:
Too many coaches are coaching the speed right out of their athletes. Some believe that it is stride frequency and others believe that it is stride length that causes speed.
The answer is neither. They are both measurements of speed but not the cause of speed. Speed is the result of net forces acting on the ground.
It is how fast the body is moving over the ground that matters. Apply more force and you will have an increase in stride length and stride frequency.
I don’t think I have anything to add to Charlie’s quote. Enough said.
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Last, but not Least, the Longer Toes Study
The Vancouver Sun gave the bottom half of Page 1 on Nov. 13. 2009 to a story from a SFU study that finds longer toes may give sprinters a leg up on other runners. Sabrina Lee (no relation), a post-doctoral fellow at SFU and Penn State researcher Stephen Piazza found that longer toes and a unique ankle structure give sprinters a “burst of acceleration” over others.
You can read the various articles here and here. Snippet here:
Long toes provide sprinters the advantage of maintaining maximum contact with the ground just a little bit longer than other runners.
‘We wanted to see how much acceleration we could get out of the model when we changed the tendon lever arm and the length of the toes,’ said Piazza. ‘What we found is that when the Achilles tendon lever arm is the shortest and the toes are longest, we get the greatest acceleration.’
This is a bit of a contradiction to the reducing ground contact theory, especially during the latter stages of a 400 meters.
The moral of the story: Speed is all about covering distance in the shortest amount of time. Everything you do in your training plan has to must reflect a training element to increase speed, power and strength.
I always wondered why they would say that minimising ground contact time is so important when the only way you can gain speed is to push off the ground, so why encourage people to risk compromising speed in an attempt to decrease contact time.
Jimson Lee says
it was all in Dr. Mann’s research. I am trying to contact him to re-release his book.
interesting but like you said jimson, coach winters has already advocated it , and i agree speed endurance and strength the key over 2s and 4s, even 100 from 60 thru to 100
ground time is important, ie, the lack of in all out sprinting, its the power produced while clawing the ground that propels the individual, also how many world class sprinters have been coming out of germany lately? still agree with jimson . also armin hary in his official biography, did a hell of alot of speed endurance and repetitive strength work, also concentrating on stride length and cadence, the germans have long gone away from real speedendurance. very few train athletes like clyde hart and why? i just dont know, well i do ! it entails alot of hard work and real , real ,real desire
@ juan martin: Horizontal forces are actually more important than vertical forces. First of all, the body is propelled fowards by what we do on the ground. As the foot hits the ground beneath the hips (ideally), force is generated horizontally by hyper extending at the hip joint. Second, usain bolt travels 2.8m per stride at top speed but has only a 5-10cm vertical movement. Slower distance runners have more vertical movement than sprinters.
If your theory was correct and speed is more reliant on vertical forces, then involvement of the quadriceps would be of primary importance (as it is in a vertical jump, slam dunk and volleyball pike). Any top sprinter with good technique will tell you they feel the burn in their glutes not quads at the end of a 100/200. 400 may be more reliant on the quads due to footstrike taking place further in front of the hips.
How we train this horizontal strength and power is NOT by doing oly lifts, deadlifts and squats variations. Disagree? Let me know what you think?
imho, “long toes” and “unique ankle structure” can be prosthetically augmented using appropriately designed footwear, [unless that comes under the ambit of prohibited facilitators]. Maybe they ought to do a study of how efficient such artificial aids can be in cutting down those final tenths and hundredths of a second in the 100 m sprint.
Juan Martin says
here I send you the links for two papers that can clarify things. The case were speed is tested on a treadmill shows that the limit is on the vertical forces, but mainly in the fact that who applies forces faster suffers less from braking forces.
I would like to hear your opinion after reading the papers.
Dick Ross says
If you want to know about what causes one to run faster check out Dr.Peter Weyard’s Journal of Applied Physiology 2000 study. You’ll find that Ralph Mann is right. Speed is all about vertical force application rather than shorter minimum swing time. The study should led the reader to question whether or not the accepted methods for training to increase running speed are focused on the factors that actually cause speed to increase. Actually, mass-specific force is where it’s really at when it comes to fast running. Paw-back, claw-back, increased ground contact time and increased forward lean are speed inhibitors.
In response to FTM…..
The results clearly show vertical ground reaction forces to be over 4x greater than horizontal forces!
However, the study shows the braking force exceed the propulsive force on each step? This would never happen when sprinting (with good technique). In fact, Brughelli (2010) found that vertical ground reaction forces increase with speed, but only up to 70% of maximal speed, whereby they then plateu.
The study collected data when subjects walked at 1.25m/s and ran at 3m/s. However, most trained sprinters will reach at least 10m/s. P.s finding subjects at this level wouldn’t be too difficult as there are hundreds of guys in the country who can run at this speed. Jim hiserman explains in he’s article – greater force = greater speed, that the slower the sprinter is running, the further footstrike takes place in front of the centre of mass, thus increasing vertical ground reaction forces, ground contact times e.t.c. Perhaps further study is required to compare walking, jogging and sprinting ground reaction forces in 3 planes of motion – medio-lateral, horizontal and vertical. My prediction would be the horizontal to vertical ratio increases as speed increases.
Sprinting mechanics change on a treadmill. As the belt feed travels rearward it also assists in dragging the foot backwards, so less horizontal force is required from the subject. Overground running requires the sprinter to push their bodyweight fowards, whereas treadmill running does more of the work for them. All the subject really has to do on the treadmill is support their own bodyweight at ground contact and keep their ground support foot moving at the same speed as the belt (McKenna et al, 2007).
My conclusion is, vertical forces increase as running speed increases (up to 70%), but horizontal forces increase at a greater rate than vertical forces as running speed increases all the way to 100% speed, thus making horizontal forces more important when sprinting. Vertical forces play their part but most training emphasis should be placed on the horizontal vector. Good vertical jumpers are not always good sprinters and sprinters are not always good vertical jumpers, therefore although there is some transfer between the 2, they are both independent variables.
brandon morton says
I think ground contact time is subjective and specific to the athlete. Coaches have to be careful preaching this to athletes. Before you know it you are going to find athletes who are purposefully trying to stay on the ground longer not realizing that ground contact time is a result of applying force. They will just end up running slow as a result of trying to be powerful. You don’t try to be powerful, it has to be something that is programmed into your body with 100s of repetition. Ground contact time isnt even something you should be trying to fix. If they know how to apply force whatever the ground contact time is thats what it will be.
There is no secret to sprinting, the secret is there is no secret lol I got that from tom tellez. You have to sprint to become better and if your putting force into the ground naturally because you understand how and your body is able to apply force then your ground contact time is going to be whatever its going to be. The question is when your foot is on the ground applying force how quick can it apply force and is it applying the full amount of force it can for that time. That will improve stride length and frequency.
Kevin White says
Well, After reading all the above statements, It seems pretty clear to me that horizontal and vertical forces, both are equally important for increased sprinting speed. The real question lays with the transition of the two and when it should occur. As ground time, vertical forces, momentum and lean should be the focus at the start of a 100m sprint, the transitioning to horizontal forces for the finish to achieve top speed are just as vital. You must have both thus working together harmoniously, Which to me is just common sense. When to begin the transition is the question. The same transition happens in the 200 meter race, as you enter the straight final 100m, so my hypothesis is, the transition begins at the 50 to 60m mark in the 100m race to achieve ones top speed. Elongated toes and Ankle structure can’t realistically be changed. That’s ones individual anatomy, not a mechanics or training issue. Though it may make for a ground contact difference. I believe Low heel recovery plays the same role as having elongated toes, etc…, which is an important teachable technique for all Sprinters. So bottom line, it’s not about one or the other,(vertical & horizontal) It’s how to utilize them as one, Which in the end, happens to be a Sprinters Ultimate Goal….To Be Number 1!