Basically, there’s a treadmill moving forward. And so his idea is to perform what is essentially overspeed.
The main thing I was thinking was, if you are landing on an object that’s already moving forward, wouldn’t that add to the braking forces?
If the athlete lands on a surface moving forward, wouldn’t that create a resistance to their negative footspeed, which increases ground contact time, and takes more force and energy to get the contact point (foot) under and behind the COG?
Also, since it is supplying additional horizontal force in such a manner, couldn’t that stimulate inhibition of the sprinter’s horizontal force? Maybe that is why he says the vertical forces produced by the athlete will be greatly increased - as the body will be producing less horizontal and thus put more into the vertical?
I think your concerns are well-founded and were shared by Charlie.
There’s some interesting research showing a substantial benefit to overspeed training via slight downhill incline running (and in conjunction with uphill running). However, that seems to alter mechanics much less negatively than treadmill or towed overspeed.
Lkh, could you please share the publication(s) that provide evidence against towing? I’m familiar with the research on uphill-downhill running but haven’t seen anything that suggests towing is a less effective means of achieving supramaximal speeds than downhill running. This seems counter-intuitive to me, as towing on a track should be more similar biomechanically to actual sprinting than downhill running and is also very similar to wind assisted running.
I doubt that you will get much agreement that being towed–by either another sprinter or a treadmill–is similar to actual sprinting, particularly with Charlie, John Smith, Steve Francis. Mike Young and others opposed, and I personally have never had a towing apparatus and would never go anywhere near it. There were a couple of old threads about contrast training, and some people other than me posted both some Russian research that the optimum incline/decline was 5 degrees (not the 1-3 degrees mentioned by Speed Dynamics) and that a couple of studies had been done on towing improvements on sprinters and the improvement was virtually none.
This is a study done about specifically overspeed using downhill running (no towing, no up/down contrast):
I am not aware of anything showing equivalent improvements from towing. I believe this is one of the papers (or similar) posted on here about overspeed in the past. But once again, it does not show any real improvement beyond 10 meters for overspeed:
Thanks for that. I’m familiar with the first study. The second study used assisted accelerations of only 18m, so you would not expect improvements beyond early acceleration. I don’t think you can conclude that downhill running is better than towing from these studies. I have stayed away from downhill running because it’s very difficult to find a suitably sloped surface that is sufficiently even to make it feel safe to run at supramaximal speeds.
Treadmill running is not a form of towing.
I have built myself a pulley-based towing device that allows me to run up to 80m (or more if I use a longer cord) with relatively constant assistance if towed by my 9 year-old son. Using this device (which cost me about $10 to make) I can cover the 60m in about 0.2s faster than without it. If you saw a video of me running with this device you would not be able to tell that there is anything different. Video analysis suggests that half of the increase in speed comes from increased stride length and the other half from increased stride frequency. It feels very similar to running with a strong tailwind.
The 1080 sprint device, while I haven’t used it myself, is capable of overspeed application via towing in the most incremental of velocity adjustments. This has profound theoretical implications and it will be interesting to see the extent to which it will be used by coaches.
I believe Charlie cited, at one point, research conducted by FIDAL questioning/disputing the potential effectiveness of towing though I never viewed the material.
I will post the link when I get to my computer, but the paper I’m thinking of on downhill overspeed is a 2009 one by Paradisis et al.
The researchers created a platform that was 20m horizontal, 20m uphill at 3 degrees, 10m horizontal at top, 20m downhill at 3 degrees, and 10m horizontal. Total distance of 80 meters.
The group that did uphill + downhill improved from a maximum velocity of 8.25 +/- 0.69 meters per second to 8.60 +/- 0.68. They weren’t world beaters at the beginning or the end, but the improvement is significant. The authors also documented changes in stride rate and stride length, but I think that’s a fairly pointless exercise.
Oh, and the training was 6x80m three times a week.
Super duper basic training program that was shared by the horizontal only sprinters (who trained on a flat surface and whose max speed went from 8.12 to 8.26). Obviously the load of 8x60 will be much different on an uphill/downhill course than a flat course. But I’m not sure how the researchers could control it with any exactitude
I’ve always questioned the overspeed running thing, particularly in case of treadmills or towing devices. I still like to utilize tailwinds sometimes in training, but when you think critically about what is happening, it makes you wonder. It seems to me that its more of a training tool to give context to an athlete who, for example, may be an over-pusher & stays on the ground too long. Running with the wind can help them learn to get the foot down and then back off of the ground without staying on the ground too long and skewing the leg cycle to the backside, since the wind is helping them propel the body down the track. On the flip side, someone who tap-dances their way down the track may be better served running into a head-wind, as this will give them the emphasis to push their mass more horizontally down the track.
In general, though, I don’t see much benefit from overspeed in and of itself. Research shows that elite sprinters do not move their limbs much faster than sub-elites, so the idea of speeding up the movements doesn’t hold much ground. Additionally, too much over-speed work could lead to someone biasing towards less of a horizontal pull->push and end up with more of a vertically applied strike (since the wind or towing is replacing the need for horizontal force). The end result would be that, without assistance, the athlete then just bounces their way down the track with longer flight times, greater amplitudes of flight, but less ground covered horizontally each stride.
In physics, impulse is force x time, and an excessive amount of overspeed volume could cause a shift towards less time on the ground with less force production. There is no stimuli in overspeed training to produce more force in less time. Is it possible that training with shorter ground contact times could cause the body to adapt with greater RFD? Maybe. But considering there isn’t a need for the body to do this I don’t think it would really happen.
How could we aim for greater RFD? Heavy isometrics provide the body with the need for greater RFD, as the body senses it needs to overcome a load that it seemly cannot overcome. Therefore it skews towards to producing more force in a shorter amount of time and activating higher threshold motor units. Also, slightly heavier sled pulls are shown to help with RFD, but if you go too heavy then you start changing the demands of the sprint too much, mechanics fall apart, GCT’s lengthen excessively, etc.
As with any training means…moderation and critical thinking are key
With treadmill and towed overspeed, I think you get the wind-assisted type effect: you are traveling faster in the air because of the greater-than-normal speed at which you are being pulled through the air, and then you do not have to apply as much force to travel this greater-than-normal distance, so your GCT can decrease. This would explain why robin1 notices an equally proportionate improvement in stride frequency and stride length.
However, the reason you’re running faster in downhill running is slightly different, I believe. You’re traveling faster through the air, yes, because you’re gravity-assisted, but I don’t think that’s the most significant thing happening. Instead, your stride length is improving because you are getting a marginally-greater flight time and therfore the chance to extend the leg downward farther and consequently faster. That equals a harder “punch” into the ground, to borrow Weyand’s description.
What that means is that it’s quite different from towed/assisted flat ground running, because the practical effect is greater vertical displacement of the COM! You get to, in effect, experience the effect of running like someone much faster than yourself - and apply more force into the ground as a result. You get greater hip height than you normally do, unlike in towed running, where your vertical displacement is the same
In that sense, I think it may be better compared with plyometric training than other forms of overspeed.
Anyone disagree with my armchair theorizing?
If I’m right, it might explain the positive research on downhill v the less clear research on towed
So I would disagree with your assertion, athletex, that there is no mechanism in any overspeed training to apply more force in less time. With downhill running, you get an exaggerated period of time to accelerate the leg downward, therefore resulting in greater force applied at impact.
It’s punching someone with 1 inch of buildup v a full swing. Even Bruce Lee was better when he could accelerate his fist that extra distance
Edit: the roughly-equal swing times for both faster and slower guys doesn’t mean that their limbs are moving at roughly-equal rates in each phase of the swing. Faster guys spend more time in the front half of the swing, because they swing forward faster and higher and experience greater vertical displacement, giving the leg more room to accelerate.
You probably know that already, I’m more saying it to myself, to remember the biomechanics of all this
As stylee is saying, downhill increases the vertical displacement, so you will alter the mechanics by having a GCT point landing closer to being bottom-dead-center relative to the COM, increasing hip height. But, would this particular alteration in mechanics have any implications? Because when you get back on the flat, you won’t have the same distance from point of GCT to COM. It will be a further distance on the flat, and so I’m wondering if downhill running is too different for the body to apply the adaptations onto race-specific running on the flat?
The paper noted slight shifts in running mechanics for the downhill group when brought back to flat running for the time trial after the training: the shank angle at toe-off increased, and the hip angle was similarly increased at the same moment - that’s because the toe-off was occurring sooner and so the leg wasn’t “tilted” quite as far forward when the runners finally left the ground. That equals shorter GCT and reduced backside mechanics.
For an illustration, I refer back to James Smith’s (I believe) posts with screenshots of Walter Dix’s recent form, as compared to a much slower runner in the same race. The forward lean at toe-off (the acuteness of the shank angle?) was much greater for the slower guy, while Dix’s shin was much more vertical.
This is apparently the only paper by Paradisis 2009 on the subject, but the structure of the research seems to be a bit different:
Int J Sports Physiol Perform. 2009 Jun;4(2):229-43.
Combined uphill and downhill sprint running training is more efficacious than horizontal.
Paradisis GP1, Bissas A, Cooke CB.
The velocity improvement of ~4.5% seems to be consistent across researchers, but this is for up/down contrast overspeed, not overspeed by towing or downhill, and this is the reason that I have used contrast overspeed only. I have seen downhill only type overspeed as “all pain, no gain” so don’t see a reason to use it, at least that’s the way I’ve seen it in the past. What I do find interesting is that multiple investigators have found noncontrast overspeed to produce gains in the first 15-20 meters only, but it does produce gains. If you are really looking for a maxV boost, you would see this as a fail. But maybe we should see running slight downhill as a way to improve acceleration instead, maybe in the first part of Phase I?
The second second, does not have a robust design. There needs to be a control group.
Practical Applications
This study demonstrates that both AST and RST produce training adaptations in elite female soccer athletes resulting in significantly improved 40-yd (36.6-m) maximal velocity. Although both AST and RST resulted in greater improvements in 40-yd (36.6-m) maximal velocity as compared to TST, the means by which the outcome occurred differed between the 2 training protocols. Therefore, the incorporation of 1 or the other of these 2 modalities into a speed enhancement training program must be based on the sport-specific demands on the athlete. Assisted, or supramaximal, sprint training increased the 40-yd (36.6-m) velocity by improving acceleration from standing to 5 yd (4.6 m) and from standing to 15 yd (13.7 m). Accordingly, this speed enhancement modality would best be used in athletic populations that participate in events requiring rapid acceleration over distances of 15 yd (13.7 m) or less. The RST protocol resulted in a comparable increase in 40-yd (36.6-m) maximal velocity; however, this improvement occurred as a result of faster acceleration from 15 to 25 yd (13.7–22.9 m) and 25 to 40 yd (22.9–36.6 m). Thus, RST protocols can be used with athletes participating in events that allow the attainment of maximal velocity over distances >15 yd (13.7 m).
The second study, does not have a robust design. There needs to be a control group.
Practical Applications
This study demonstrates that both AST and RST produce training adaptations in elite female soccer athletes resulting in significantly improved 40-yd (36.6-m) maximal velocity. Although both AST and RST resulted in greater improvements in 40-yd (36.6-m) maximal velocity as compared to TST, the means by which the outcome occurred differed between the 2 training protocols. Therefore, the incorporation of 1 or the other of these 2 modalities into a speed enhancement training program must be based on the sport-specific demands on the athlete. Assisted, or supramaximal, sprint training increased the 40-yd (36.6-m) velocity by improving acceleration from standing to 5 yd (4.6 m) and from standing to 15 yd (13.7 m). Accordingly, this speed enhancement modality would best be used in athletic populations that participate in events requiring rapid acceleration over distances of 15 yd (13.7 m) or less. The RST protocol resulted in a comparable increase in 40-yd (36.6-m) maximal velocity; however, this improvement occurred as a result of faster acceleration from 15 to 25 yd (13.7–22.9 m) and 25 to 40 yd (22.9–36.6 m). Thus, RST protocols can be used with athletes participating in events that allow the attainment of maximal velocity over distances >15 yd (13.7 m).
