As an athlete i trying to figure out how to apply this statement to my running and/or practice…any thoughts guys???
Faster Running Speeds Are Achieve By Applying More Force To The Ground.
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Participant
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Participant
Apply more force to the ground. Just kidding!
To apply more force, you either have to spend longer on the ground (not good), or produce the force quicker (good). To produce the force quicker, you could utilize stuff like plyometrics, which has been proven to reduce contact time when running, which is beneficial.
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Participant
The importance of applying more force to the ground in order to run faster is based on a study in 2000 and confirmed by another study (same author) in 2005. However in 2009 the same author expressed some doubts about his original conclusion. In 2010 (still in print) that same author now says that top speed is actually limited by the ground contact time that we can achieve.
In terms of training, if you were to do a drop jump (or hop or bound etc) to or from the same height but do it quicker (shorter ground contact time) you would in fact generate more force. Therefore it seems logical to just practice doing everything (plyometric) quicker as you attempt to overcome ground contact time which limits how fast you can run and you incidentally increase force production.
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Participant
ok cool
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Participant
As an athlete i trying to figure out how to apply this statement to my running and/or practice…any thoughts guys???
I think it’s something you shouldn’t actively think about, if your program includes all the correct elements then in most cases it should happen. From a technical standpoint, taking a few cues from CF I would focus on staying relax and stepping down.
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ParticipantI am sending the video podcast to those that ordered the DVD in a week regarding plyomentrics-olympic lifts.
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Participant
As an athlete i trying to figure out how to apply this statement to my running and/or practice…any thoughts guys???
You have to remember that force is a vector quantity. Applying greater amounts of force only aid in sprinting when applied in the correct direction.
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Participant
[quote author="izzle1989" date="1269183456"]As an athlete i trying to figure out how to apply this statement to my running and/or practice…any thoughts guys???
I think it’s something you shouldn’t actively think about, if your program includes all the correct elements then in most cases it should happen. From a technical standpoint, taking a few cues from CF I would focus on staying relax and stepping down.[/quote]so just relax and put your foot on the ground….that simple?
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Participant
I think the idea that reducing ground contact time makes you run faster is putting the cart before the horse. Ground contact time, for a specific individual, is controlled by how fast he/she is moving over the ground. Unless the sprinter’s mechanics are altered, the foot strikes the ground in the same relative position (under the body) and leaves the ground at toe off in approximatel the same position as before. In other words, an elite sprinter who improves his max speed doesn’t contact the ground farther behind his center of gravity, and doesn’t toe off earlier in his stride. The ground contact time is shorter simply because he is going faster over the ground, the legs are traveling through space faster, and the foot spends less time on the ground.
The first assumption is the correct one, IMHO, that to go faster you need to apply more force during the alloted ground contact time. To go faster, even more force has to be applied during what is now a shorter contact time.
Improving your ability to generate force, and steepening your personal force/time curve (be able to generate more force and apply it at a higher rate) is what makes you run faster. The ground contact time, while it limits the time alloted to generate force, is an artifact and product of speed, not the other way around, IMHO.
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Participant
I think the idea that reducing ground contact time makes you run faster is putting the cart before the horse. Ground contact time, for a specific individual, is controlled by how fast he/she is moving over the ground. Unless the sprinter’s mechanics are altered, the foot strikes the ground in the same relative position (under the body) and leaves the ground at toe off in approximatel the same position as before. In other words, an elite sprinter who improves his max speed doesn’t contact the ground farther behind his center of gravity, and doesn’t toe off earlier in his stride. The ground contact time is shorter simply because he is going faster over the ground, the legs are traveling through space faster, and the foot spends less time on the ground.
The first assumption is the correct one, IMHO, that to go faster you need to apply more force during the alloted ground contact time. To go faster, even more force has to be applied during what is now a shorter contact time.
Improving your ability to generate force, and steepening your personal force/time curve (be able to generate more force and apply it at a higher rate) is what makes you run faster. The ground contact time, while it limits the time alloted to generate force, is an artifact and product of speed, not the other way around, IMHO.
I agree, in general, with you. The Weyand study was descriptive, not prescriptive. It is like someone telling me that the fastest guys run 100m under 10s, while this is true, it does not tell me in any way how to do the same.
Some people used to think that faster guys had much faster stride frequency; Weyand showed that in fact there is little difference in that respect, the key factors being force produced on the ground and time spent on the ground. This is good, but so what? How can I accomplish these things? He did not say, nor should he, because he is a scientist, and they understand the limits of their research; however, lay people rarely do, and so tend to extend scientific results unwarrantedly. Unfortunately, some mystical people make an entire training system based on these studies, and all of a sudden getting as strong as possible is seen as the crux for greater speed.
In my opinion, fast running is mainly a neurological skill, something that has to be developed by many hours of practice. Some people are more gifted than others, so they learn what muscles to activate more efficiently and quickly than others. But we all need practice. And what is the best practice? This cannot be answered scientifically, the variables are too numerous and inter-related. We can only go on experience. Try and model what the most successful people have done, and make it fit your situation. Nothing more to it. Describing to me how great guys run fast does not, and will never, help me to run faster because the “how” is too individualistic. -
Participant
It’s intresting to see Fasuba’s winter preparation, especially comparing his training of 2006 with 2007. Both years his winter preparation consisted of 17 weeks, but number of training session differed a lot. In 2006 he did 73 session, in 2007 43 sessions. Automatically in 2006 there were more speed days 36vs.29, especially endurance days 31vs.18, number of weight days were almost the same. Results in 2006 – 6.56 and in 2007 – 6.52, simply more work didn’t bring better performance but higher training load could give some dividents for 2007, who knows. In 2005 ran 6.54 with zero weight training sessions.
Pognon was a bit better at OHB test over Fasuba, but Fasuba was much stronger at squat, Fasuba b/w 74kg and squat 210, Pognon b/w 84kg and squat 170kg -
Participant
My coach thinks I apply to much force, not that I’m particularly powerful but he reckons by watching and also listening to my foot contact that I hit the track too hard with a clawing action (he says similar to Chambers) and that perhaps my foot deforms or even collapses when hitting the ground, and then has to recover and get back into the right position before take off. Another coach has commented on the sound of my foot contact that its just too harsh sounding and loud to be efficient!
My coach has suggested trying a lighter contact and thinking about the dorsiflexion of the foot so that it reacts off the track quicker instead of maybe sinking into the track. We are doing plyos to try and decrease contact time as well and strengthen the feet and ankles
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Participant
It’s intresting to see Fasuba’s winter preparation, especially comparing his training of 2006 with 2007. Both years his winter preparation consisted of 17 weeks, but number of training session differed a lot. In 2006 he did 73 session, in 2007 43 sessions. Automatically in 2006 there were more speed days 36vs.29, especially endurance days 31vs.18, number of weight days were almost the same. Results in 2006 – 6.56 and in 2007 – 6.52, simply more work didn’t bring better performance but higher training load could give some dividents for 2007, who knows. In 2005 ran 6.54 with zero weight training sessions.
Pognon was a bit better at OHB test over Fasuba, but Fasuba was much stronger at squat, Fasuba b/w 74kg and squat 210, Pognon b/w 84kg and squat 170kgFasuba ran 6.47 in 2007 – I was in the race!
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Participant
My coach thinks I apply to much force, not that I’m particularly powerful but he reckons by watching and also listening to my foot contact that I hit the track too hard with a clawing action (he says similar to Chambers) and that perhaps my foot deforms or even collapses when hitting the ground, and then has to recover and get back into the right position before take off. Another coach has commented on the sound of my foot contact that its just too harsh sounding and loud to be efficient!
My coach has suggested trying a lighter contact and thinking about the dorsiflexion of the foot so that it reacts off the track quicker instead of maybe sinking into the track. We are doing plyos to try and decrease contact time as well and strengthen the feet and ankles
You are likely overstriding and plantarflexing before contact. You wouldn’t be applying too much force, but rather applying force inefficiently!
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Participant
[quote author="Irish100m" date="1269484913"]My coach thinks I apply to much force, not that I’m particularly powerful but he reckons by watching and also listening to my foot contact that I hit the track too hard with a clawing action (he says similar to Chambers) and that perhaps my foot deforms or even collapses when hitting the ground, and then has to recover and get back into the right position before take off. Another coach has commented on the sound of my foot contact that its just too harsh sounding and loud to be efficient!
My coach has suggested trying a lighter contact and thinking about the dorsiflexion of the foot so that it reacts off the track quicker instead of maybe sinking into the track. We are doing plyos to try and decrease contact time as well and strengthen the feet and ankles
You are likely overstriding and plantarflexing before contact. You wouldn’t be applying too much force, but rather applying force inefficiently![/quote]
Yeh could be, by applying to much force i didnt mean i produce a lot of power and forace, just that my foot really hits the ground hard and makes a very loud and flat/harsh sound.
I need to get a video on here …
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Participant
I am sending the video podcast to those that ordered the DVD in a week regarding plyomentrics-olympic lifts.
Great article!
The charts on the differences in stride frequency and stride length between elite and youth are great as well.
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Participant
Force versus contact time (or force production time)? Heavy strength training versus plyometric training? New ideas versus persisting with old ideas?
One thing for sure is that we don’t know for certain that a dramatic increase in strength provides any measureable improvement in speed (and yet people spend countless hours improving their strength for no discernable gain). We know for certain that a plyometric training program decreases ground contact time and can produce a measurable improvement over 10m which is not lost over 100m. We know for certain that sprinters who run at 11.8 m/s (sub 9.9s) do so with ground contact times of less than 85ms but we sure can argue that there are sprinters who are just as strong if not stronger who cannot run sub 10s and most likely sprint with ground contact times of 95ms (at 10.2m/s). Is a plyometric program enough to bridge the differential in ground contact time or will it have to be modified to address this differential? We don’t know at all whether maximal plyometrics can be improved upon and we haven’t even looked at minimal (force) plyometrics as an option. Nor have we looked at minimal sprint contact time sprinting as a method of training. If sprinting is neurological then I would suggest we practice the neurological skill because only through such practice can it be improved upon.
To make a long and perhaps unpopular story short, what is the harm in sprint running practice with a goal to run 40m (for example) as if one was running on water and had to step quickly so as to not allow the foot to sink into the water? It may result in an initial slowing down by 1 metre over 40m but with persistence could produce far more profound improvements as one acquired the skill of quicker activation and relaxation of muscles.
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Participant
Force versus contact time (or force production time)? Heavy strength training versus plyometric training? New ideas versus persisting with old ideas?
…We know for certain that a plyometric training program decreases ground contact time and can produce a measurable improvement over 10m which is not lost over 100m.
I disagree with your reasoning here. Yes plyos improves 10m acceleration, but so does stength training. And plyos don’t reduce contact time, speed over ground does. Plyos do improve RFD which leads to more force application per stide which leads to higher speeds which leads to reduced ground contact time, but it is an indirect, not direct, improvement and is still an artifact of the higher speed. And ground contact times are much higher in the first 10m.
We know for certain that sprinters who run at 11.8 m/s (sub 9.9s) do so with ground contact times of less than 85ms but we sure can argue that there are sprinters who are just as strong if not stronger who cannot run sub 10s and most likely sprint with ground contact times of 95ms (at 10.2m/s). Is a plyometric program enough to bridge the differential in ground contact time or will it have to be modified to address this differential? We don’t know at all whether maximal plyometrics can be improved upon and we haven’t even looked at minimal (force) plyometrics as an option. Nor have we looked at minimal sprint contact time sprinting as a method of training. If sprinting is neurological then I would suggest we practice the neurological skill because only through such practice can it be improved upon…
I think chasing reduced ground contact times is wrong-minded. I can tap my foot very rapidly (you should see my niece, 15 years of tap dancing lessons, but slow as molasses) but that does nothing to improve speed. Again, the reduction in ground contact time is a by product of speed, the speed comes first. In fact, the shorter ground contact time actually works against the increase in speed in that you have less time to produce force. If you cound think of a way to increase ground contact time without reducing speed or the ability to produce force, now that would be something.
IMHO, the two primary goals of training (which should lead to improvements in the ultimate goal of more speed) are to increase the ability to generate force to the ground (functional strength) and the ability to apply the force very rapidly (RFD). In young or novice sprinter, especially those that are not naturally strong, both are important. As you mature in strength and experience, RFD becomes the dominant animal to chase.
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Participant
[quote author="Jeremy Richmond" date="1269527063"]Force versus contact time (or force production time)? Heavy strength training versus plyometric training? New ideas versus persisting with old ideas?
…We know for certain that a plyometric training program decreases ground contact time and can produce a measurable improvement over 10m which is not lost over 100m.
I disagree with your reasoning here. Yes plyos improves 10m acceleration, but so does stength training. And plyos don’t reduce contact time, speed over ground does. Plyos do improve RFD which leads to more force application per stide which leads to higher speeds which leads to reduced ground contact time, but it is an indirect, not direct, improvement and is still an artifact of the higher speed. And ground contact times are much higher in the first 10m.
We know for certain that sprinters who run at 11.8 m/s (sub 9.9s) do so with ground contact times of less than 85ms but we sure can argue that there are sprinters who are just as strong if not stronger who cannot run sub 10s and most likely sprint with ground contact times of 95ms (at 10.2m/s). Is a plyometric program enough to bridge the differential in ground contact time or will it have to be modified to address this differential? We don’t know at all whether maximal plyometrics can be improved upon and we haven’t even looked at minimal (force) plyometrics as an option. Nor have we looked at minimal sprint contact time sprinting as a method of training. If sprinting is neurological then I would suggest we practice the neurological skill because only through such practice can it be improved upon…
I think chasing reduced ground contact times is wrong-minded. I can tap my foot very rapidly (you should see my niece, 15 years of tap dancing lessons, but slow as molasses) but that does nothing to improve speed. Again, the reduction in ground contact time is a by product of speed, the speed comes first. In fact, the shorter ground contact time actually works against the increase in speed in that you have less time to produce force. If you cound think of a way to increase ground contact time without reducing speed or the ability to produce force, now that would be something.
IMHO, the two primary goals of training (which should lead to improvements in the ultimate goal of more speed) are to increase the ability to generate force to the ground (functional strength) and the ability to apply the force very rapidly (RFD). In young or novice sprinter, especially those that are not naturally strong, both are important. As you mature in strength and experience, RFD becomes the dominant animal to chase.[/quote]
To be more precise plyos (with correct exercise prescription) do reduce ground contact time (Rimmer and Sievert 2000, Delecluse et al. 1995) and plyometrics are generally regarded as an explosive training method i.e greater production of force in small time increments more commonly described as greater rate of force development. I have always supported explosive strength training methods as a more specific method of training for sprinting (probably quoted Hakkinen et al. 1985 enough times already), but maintain that it could be even more specific in terms of strength training in smaller increments of time.
Re: tap dancing, the world’s fastest drummer can move his hands at a rate almost twice that of highly skilled drummers which he credits to the deliberate practice of rate of drumming (Fujii et al. 2009). I’m not saying that one needs to go to the extreme of tap dancing except for a study of short activation times but a some deliberate practice to step quicker at the expense of time over 40m for example may represent a small sprint specific short term compromise for a greater long term return. Learn to activate and relax muscles (quicker) in the same recruitment sequence as that of sprinting.
Re: force versus contact time. Has anyone tried to jump quicker and observed how much force they generate? More force.
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Member
Hi all
I have not seen this journal article discussed on this site, so I have placed some selected paragraphs below.
NB this article is freely available to all.
Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. J Exp Biol. 2012 Jun 1;215(Pt 11):1944-56. Dorn TW, Schache AG, Pandy MG.
Runners appear to use two different strategies to increase their speed. Up to ~7ms-1, running speed is increased by exerting larger support forces during ground contact, which has been shown to correlate with increases in stride length.Larger ground forces can be generated at lower running speeds because the leg muscles have enough time to develop the forces needed to lift and accelerate the body during stance (Weyand et al., 2000). At speeds near 7ms-1, however, ground contact times become very small (Kunz and Kaufmann,1981; Mann and Herman, 1985; Mann, 1981), limiting the ability of the leg muscles to generate the ground forces needed to increase running speed still further (Weyand et al., 2000).
Above ~7ms-1, the primary strategy used to increase running speed shifts from the goal of increasing stride length to that of increasing stride frequency, which is achieved by accelerating the
legs more rapidly through the air. Peak hip-flexor, hip-extensor and knee-flexor moments all increase significantly at speeds above 7ms-1 (Belli et al., 2002; Schache et al., 2011).The percentage increase in stride length was greater than that in stride frequency as running speed
increased from 3.5 to 7.0ms-1, but the opposite effect was observed at speeds above 7.0ms-1 (Fig.2A, Table2). Ground contact time decreased monotonically as running speed increased (P<0.01;
Fig.2B, Table2). Aerial time and effective vertical ground impulse both reached their maxima at 7.0ms-1 before decreasing at higher speeds (Fig.2B).Across all running speeds, SOL, GAS and VAS provided roughly 75% of the total vertical support impulse needed to accelerate the body upward, with SOL contributing as much as 50%. For speeds up to 7.0ms-1, increases in the vertical ground reaction force were due almost entirely to the action of SOL. The contribution of VAS to the vertical ground force did not increase as running speed increased.
Peak forces developed by the ankle plantarflexors decreased at the higher running speeds for two
possible reasons. First, the muscles may have been operating at lengths much shorter or longer than the muscles' optimum fibre lengths (Close, 1972; Gordon et al., 1966; Woledge et al., 1985); and second,
the contractile velocities may have been too high to allow the muscles to develop high forces.The model calculations showed that stride frequency was increased by increasing the forces generated by the hip-spanning muscles, primarily ILPSO, GMAX and HAMS, as these muscles contributed significantly to the larger hip- and knee-joint accelerations observed at higher running speeds.
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