T-Slow, thanks…point taken. In general, I tend to fight fire with fire…or maybe I was responding to condescension with sarcasm. Maybe I had received condescending tone from star61 because of so few posts on my part. I live this stuff even if I just found CF.com a few weeks ago. Besides sarcasm, is rest of my post solid for you? I seek most honest opinion.
You shouldn’t have wasted your time. There are a few simple facts that are indisputable. One is, the only thing propelling an athlete forward is the force he generates while in contact with the ground. Two, he can only generate that force when he is in contact with the ground. I’m not advocating trying to INCREASE contact time, but it is just as silly to advocate trying to reduce GCT just to reduce it. And don’t confuse the need for sprinters to develop the ability to generate more force in the short GCT that sprinting offers (improving RFD), especially at max v, with attempts to terminate GCT early. Reducing GCT means you are operating farther to the left on the force time curve…where very little force can be generated because of the very short times. How does reducing that time, which by definition then reduces the force input, make you go faster? There are a lot of great coaches out there that have no true understanding of physics, and a lot who think correlation = causation. It just ain’t so, no matter how many words you type. Its about increasing the force input during the available GCT. Reducing the GCT does not increase your ability to input greater forces, it reduces it. Again, ever shortening GCTs with increasing speed is the impediment to higher speeds in the first place, why on earth would you do something to reduce GCT even further when it does nothing to improve your ability to input forces? The focus should be on training that improves the sprinter’s ability to input greater force during GCT, which, as GCT becomes ever shorter with increasing velocity, should focus on RFD.
In short GCT is shorter for elites as they are able to (through increased rfd) move through there rom during GT faster
There is no attempt to be quick footed, it is a by product of the efficient force applied.
Good post star 
No offense was taken on my part and I meant none, just a little smart a$$ in me. I like empassioned, well thought out posts, even if I disagree. Its how we learn. As long as there is no name calling or derogatory attacks, its all good fun. Looking forward to your replies.
No question that the internet is full of fight-fire-with-fire; what’s great about here is that even if things get a little heated from time to time, people cool off and the ideas tend to be at the forefront, not personality or ego. It’s great to have another experienced, intelligent member here to learn from! I look forward to reading more of your posts.
Star, I appreciate a little smart arse in folks as well…prolly why I enjoy dropping a little sarcasm here and there myself. I also enjoy impassioned, smart, well researched debate. It is how we evolve in just about everything…academics, politics…and track and field. If everyone agreed about everything the world would be a very dull place.
I just assumed it was Weyland’s sled pull study you were referring to. Thanks for the link. I would still hesitate to put too much stock in research done on a treadmill. Bosch disputes any biomechanical data done on a treadmill, unless the data is meant to prove some point specifically about treadmill running. The ground is moving for you, the hip and leg anatomy do not work in same biomechanic, the stance mechanic is not specific to sprinting over stable surface and force applications are different…again, mostly because ground is moving for you. Hamstrings don’t have to do much on a treadmill. Furthermore, Weyland tells you up front that he has only worked with 30 or so subjects of varying sprint abilities. First off, that is not a big enough sample group for me to put much trust into his data and findings. Secondly, I couldn’t tell you if any of his subjects have ever run under 11 seconds in the 100m. Unskilled runner’s data on a treadmill is not specific enough to compare to elite sprinters running over solid ground…for me at least.
I will again defer to Ralph Mann, who has done the most extensive research on nothing but elite level sprinters and hurdlers (has to be over thousand by now, maybe couple thousand) over the last few decades or so. He has biomechanically analyzed every, yes every, elite American sprinter and hurdler since 1982. I believe he has been publishing his research data and findings since 1984. His latest and best publication was this year, 2011. It is fantastic (as they all have been) and I’d suggest it to anyone who coaches runners. You can find it on Amazon. His nearly 3 decades of research says that the best male sprinters in the world spend 0.087 seconds or less, while poor sprinters spend 0.101 seconds or more. Ton of data on Women as well. His good and poor evaluations are relative to thousands of elite sprinters running actual races, not 33 poor schlubs pulled off the local track and put on a treadmill. Mann’s good sprinters run approximately 10 sec or less, while his athletes from the poor category are still making NCAA finals. Again, I think it is obvious if a 10 sec or less guy tried to quicken GCT to 0.050 sec or less, he would obviously not be able to apply enough force needed to run his fastest. That is absolutely not what I am trying to suggest in my previous posts. My original statement says “short” contact times for fast, and “longer” for slower…not shortest and/or longest. I use these words in context to what I understand Mann to have already figured out. I do not suggest that to run fast you have to shorten GCTs to ridiculous levels. There is obviously tremendous power outputs by very strong athletes inside of the 0.087 GCTs I am referring to as “short”…in these posts. “Longer” is spelled out in the numbers I’ve already quoted. As for my use of the word longer for slower pace racing, please see Mann’s chapter on what elite level quarter milers from the past 3 decades do while they are on the ground. I feel like the folks who continue to debate that I say the absolute shortest GCT would make for the fastest run have not read my entire, long-winded posts…or jumped to conclusion on my original post.
Many track coaches do misunderstand biomechanics quite a bit, I definitely agree whole-heatedly with that statement…but none of the ones I name dropped in my last post misunderstand biomechanics. I will have to stop carrying on now…my wife is beginning to get mad at me. Until next time…peace.
I hadn’t been to a message board in some time. When I saw this one I got excited for potential of learning and sharing on here. I did forget how easy it is to get caught up in the anonymity of a message board. I look forward to future discussions as well.
Mann’s data indicate that the fastest sprinters have the shortest GCTs, I think that should be obvious. ANY sprinter will reduce his/her GCT by simply sprinting faster. Weyland et. al. have also measured the travel that the body does during GCT, and it does not change with speed. Meaning, GCT initiates at about the same place relative to COG and terminates some microsecs later at a position relative relative to COG. The position of GCT at termination relative to COG doesn’t deviate, meaning there is no early termination of GCT at faster speeds. Secondly, early termination would only be of benefit if it enabled the next stride to start sooner, i.e., higher frequency. Many studies have shown that the distinction between elite and non-elite sprinters is not frequency.
GCT is only shorter because the COG is travelling faster through that range of motion. This is a simple, but very important, disctinction, so I’ll state its significance to training again. Shorter GCTs are a result of faster sprinting, not the cause. Therefore focused training to simply reduce GCT for the sake of reducing GCT is a fruitless persuit. Train to increase force applied during GCT, and the rate at which that force is produced, should be the focus, and higher speeds, along the shorter GCTs, will follow.
This thread has been high-jacked by the discussion of GCTs. It was originally athread about “front” mechanics. My initial point was that fastsprinting folks are front side monsters. They do not exist in backsidemechanic like slower paced racing athletes. This greater front-sidemechanic running naturally results in a greater force application into theground…obvious. It is a natural result of dropping anything from agreater distance from above the ground…or another analogy you hear a lot is ahammer that is brought back further. A sprinter who begins with greatfrontside mechanics, is running efficiently and faster than everyone else inthe race, will have shorter ground contact times than everyone else in therace. The moment that sprinter over-applies force into the ground, pushesinto the ground too long, or in a slightly incorrect direction…well, thenthere goes the great frontside mechanic, and full potential for that sprinteffort.
Sprinting fast is aformula of stride length (force application) and stride rate (ground contacttimes). If everything else is solid in the running technique, then thecloser that male athlete can get to 0.085 sec for GCT, the better. Running is by nature a cyclical action, so everything that happenseffects everything else that happens thereafter. Great frontside runningresults in near full leg/hip extensions at or before ground contact, and jointflexion occurs earlier in the backside mechanic. Frontside is not justabout how high you can get your knee in front of you, but more about setting upan early and tall hip/leg extension for GC. This is where and when the force is applied. In slower pace running the leg and hip don’treach extension until later in support phase, and near end of backside groundcontact. The leg strikes with moreflexion, then re-pushes later. Where this extension occurs (literally thetiming of it) in the different paces will largely determine the GCT. Theearlier the extension, the shorter the GCT (fastest folks are near fullextension 4-6 inches before they strike ground). The later the leg/hipextension occurs, the later and less the force application, thus the longerthat athlete has been on the ground.
There is a greatvideo on the Canadian Athletics Coaches Centre website of Dan Pfaff explainingwhy Donavan Bailey lost a particular race to Mo Green. You watch the racein super-slow motion while Pfaff explains over top of video that Baileyover-pushes the ground for only two strides at somewhere around 50-60m, andthis is why he looses the race. Pfaff was Bailey’s coach at the time ofthe race, and also while he was the world record holder and the time he wasbest in the world. Bailey’s GCTs last too long for only two steps andGreen is gone (Bailey pushes the broken treadmill). There is a greatvideo on Youtube of Bolt in a race, super slow-mo from the side as the cameratravels at the same speed as the athletes. Bolt over-pushes the groundearly in the race, and is losing early. You can see his leg extensionoccurs behind him. He catches up and wins the race, and you can literallysee him in the video bring the timing of his leg extension back in front andunder him as he runs down the guy in lane 8/9. Early in the race the guyin outside lane is phenomenal. These are both easily accessible videos. There are other races on Youtube of Bolt running 400m races and whenslowed down, you can see the ground mechanic differences between these and hisfaster 100m races. Please feel free to Dartfish the GCT of these vidsyourself. They are obviously not perfect because of potential frame ratedifferences in all digital means used, but you’ll get the picture.
Please understandthat I am not trying to re-hijack this thread with leg extension talk, butunderstand that this is a part of great frontside mechanics (that beinganything that happens in front of the saggital COM mid-line of the body). Hopefully I’ve made clear that this all has a direct relationship withforce application and contact times. If you are doing nothing in trainingbut spending time applying force for longer periods of time, then you areeither running backside and slower than your full potential, of you aretraining throwers…and even then force application has a critical relationshipwith speed.
You make a tremedous number of assumptions that don’t actually meet up with scientific observations. For example, you again talk about faster sprinters having shorter GCTs because of some mechanical difference in their form…it just isn’t so. Faster sprinters have shorter GCTs because they are running faster. If you have data or film, look at GCTs of sprinters of different caliber when running at the same speed. You will find scatter with little correlation. I don’t mean to be an arse, but long winded diatribes that consist of opinon and anecdotal observation without any science to back it up doesn’t go very far on this forum.
Wow! I’m absolutely done with this thread as we keep going in circles. Everyone can do their own research on Weyland, Mann, or whoever…compare and contrast for yourselves and make your own assumptions and opinion. I’m going to stick with Mann, Bosch, Tellez, Seagrave, Pfaff, and Winkler.
Canadian Athletics Coaches Centre is a phenomenal place to find videos and documents of best coaches in the world talk about everything under the sun in track and field. No videos on treadmill running of sled pulling though. Bosch and Klomp’s “Running, the BK Method” DVD and accompanying book are also incredible resources. Mann’s latest 2011 publication, “The Mechanics of Sprinting and Hurdling” is a culmination of over 25 years of research and former publications on the best sprint/hurdle athletes in the world. It is cool because he presents the data for the biomechanic geeks then gives suggestions on how to actually present the concepts in a simpler manner to the athletes.
All of the most successful coaches all say pretty much the same thing, but just in different ways…which is what I think Star and I are doing. Short GCT are the result of fast sprinting is a little like saying bending stronger poles while pole vaulting is because of higher pole vaulting…well, yes…that’s the bumper sticker version, but there is an orchestra of factors at work. See you all on another thread perhaps.
clymb420,
Don’t be so sensitive! Star61 is just trying to interact with you. There is nothing wrong with questioning your assumptions.
IMHO the problem you are having with this thread is that you are trying SO desperately to show that you know so much!!! Calm down a bit. You are clearly a well read guy with lots of Sprinting background. You have a LOT to add to this site but… when you write 3 and 4 paragraph posts then it doesn’t really leave much room for discussion from the rest of us. If you write shorter posts with one or two central concepts then you will generate more interest.
I look forward to seeing more posts from you in the future.
I agree with macsprint. I also agree with star as ground contact does decrease as speed increases not the other way around. Clymb420 you have many valid points and front side mechanics are dependent on the amount of time you spend on the ground. From my on personal experience and videos I have posted I tend to push too long which doesn’t leave me enough time to recover and get good front side mechanics. With that being said some athletes do need to be cued to purposely reduce the gct or amount of time the foot is left on the ground to prevent pushing out the back. I learned that last statement from a few of Charlie’s posts. Thanks
Hi Izzle and Mac, I don’t think my exclamation was sensitivity to Star’s comments, as we’ve had the same exchange 3 or so times now in this thread, but frustration with myself that I have spent so much time (and typing) on this one thread…going round and round and not going anywhere. Especially since it was not having a direct relationship with thread starter’s question. I am aware of my tendency to get carried away. I do have a long post problem when challenged, and I will work on it. I was and still am excited to have found this site…didn’t know it existed until a couple of weeks ago. All that excitement has poured out in these last several posts of mine on this thread. Also, I am an oldest child so I like to share. I am now really done with this thread as I think original question of “what are front mechanics” has been answered. Looking forward to your next video Izzle. Hope to see you all on another thread.
Thanks Clymb…I’m looking forward to getting more feedback from you…You shouldn’t leave this post just yet because we know what frontside mechanics are because we still need more info on how to improve frontside mechanics…I would really appreciate your input.
I listned to Ralph Mann at a conference last year. The gist of it was - increased strength with sound technique i.e. with frontside mechanics = faster more powerful ground contact during sprinting - simple, and only one paragraph.
Did he mention ways to improve frontside mechanics?
Question for everyone. Mann’s assertions, or at least the assertions made by those referencing Mann’s data, seem to center around GCT, which is why I addressed it. In terms of reducing GCT intentionally (not just because your’re running faster) I ususally see references to terminating GCT early, or mimimizing backside mechanics. How does improving front side mechanics play into this? The only way I can see front side mechanics reducing GCT is to initiate GCT further under the body. Is there reliable data that indicates elite sprinters tend to step down further under the COG and sub-elite step down further in front?
Note: Even if it were true, any advantage could also be explained by reduced braking and not necessarily by increased frequency due to reduced GCT.
Front side mechanics can be improved with better posture. The knee simply can’t come up enough if the torso is not perpendicular or nearly so at max. velocity. and without that ideal posture, GCT will be increased due the survival mechanism/braking action-lean forward and the foot will land further ahead of the COM to “save” yourself and thus leading to a longer GCT. My belief on decreasing GCT due to improved front side actions is, in part, due to more powerful efficient counter thrust (I think that is the correct term?) that CF spoke of. If the arms/hands are coming up high enough to face or eye level, the drive knee will also come up in part as a reaction to those actions which have immediately preceded it-i.e. establishing or at least maintenance of correct posture and and active and complete arm swing. If the posture is correct and the arms are moving actively up and to the center line again as CF said many times, there is an improved “un-weighting” taking place on the support leg. That is, you will be on and the off that support leg more quickly referred by some as bouncing. Also, to clarify, the knee lift that takes place in the front side is a reaction to both counter thrust from the arms but also the reaction to ground forces and there should be no concious effort to lift the knees up higher.
Someone with more pronounced back side mechanics will usually not have proper posture and too much “dangle time” will take place with the recovery leg and thus that leg has a long distance and time to travel in the swing to get the knee up whereas I think most sprinters/coaches want to see the recovery leg/knee moving forward instantly when the foot leaves the ground. The athlete with more back side action relative to front side will take more time (I realize not everyone will agree with this assertion) and distance to get to the front-if it ever does completely.
Nice Post pioneer!