Asafa slow motion block start

Dragging his feet too much, probably one of the reason he gets run down late.

Care to elaborate? He has been one of the best starters in the world for most of his career. How does his shuffling type of initial steps change what happens late?

He starts extremely well and changes technique twice more. If he dragged his feet for the whole race he would be quicker.

Interesting to see that at 5 seconds he lets his heels come up, but by 6 seconds he has them back at his knees (almost like he was executing a form of dribbling)

He dragged for the first 3 steps then he started stepping over the knee. Great extension from beginning to end. Getting complete foot placement on each step. Looks good to me.
In asafas last race in Jamaica he didn’t do his traditional foot drag at all.

Looks pretty good to me. Appears to drag for the first 3 strides, then seems like he takes a few strides with the shin no higher than knee length, until he continues to tuck them higher until he approaches higher speeds. Only thing I might say about him is that his ankle/foot tends to land a bit ahead of his hip a bit early, I think this becomes true once he gets to his 5th stride here. Of course, I believe Jeter has the same tendency. Works for them though obviously.

Its just not efficient because of greater breaking impulse, the cost is less efficiency late in the race. Ben was technically a much better starter. In 20-30 years with the benefit of hindsight coaches/sport scientist will look back at the toe drag technique and it will be viewed as nonsensical.

While it’s certainly debatable as to whether it is a point of direct instruction or avoidance, the undebatable physics are such that the predominance of horizontal forces during block clearance and initial acceleration create a situation in which the exaggerated curvilinear path through space manifested by higher heel recovery (while a mechanical advantage in the vertical sprint position due to the shorter lever arm) is a longer path/duration in comparison to the toe drag in which the lever is longer yet the path through space is shorter.

Breaking impulse is substantially more affected via where ground contact occurs in relation to the hips. While there is an increased friction component as the toe drags, this is offset by decreased duration of the recovery cycle (during block clearance and initial acceleration).

That said, I’m not one to say “you should do this or that with the recovery leg during block clearance”; rather, optimize what is already being done. It is fundamental to acknowledge the physics, however.

the 2 races ive seen from him this year, he has not toe dragged at all

You are oversimplifying a complex interaction of moment of inertia and angular velocity of the swing leg, with the simple argument that the drag affect will be off set by the reduction in ROM.

Breaking impulse is substantially more affected via where ground contact occurs in relation to the hips. While there is an increased friction component as the toe drags, this is offset by decreased duration of the recovery cycle (during block clearance and initial acceleration

There is no data to support this claim , if you do have any peer reviewed data please provide.

Since there is no peer reviewed data that has been collected from the analysis of the world’s elite (coefficient of friction of the toe drag and etcetera), this is all academic. That said, your position of the toe drag being viewed as non-sensical in the future is no less of a supposition; as what we already know about moment of inertia and the angular velocity in principle is, in my view, sufficient to extrapolate to sprinting and support what I’ve stated regarding the advantage of minimizing heel recovery during the initial strides.

On the topic of this academic discussion, I would propose that the most optimal condition is not to drag the toe but maintain it in the closest proximity to the track without actually making contact; as the decreased movement amplitude of the recovery leg during the initial strides is intuitive enough in my view. It would have been prudent for me to state this initially as we certainly do not require scientific data to agree that it is advantageous to reduce drag coefficient whenever and wherever possible.

As an aside, I’ve always found it annoying how commentators and the peanut gallery have criticized Bolt for his start/first 10 when, point of fact, while his reaction time is what has lacked- his first 10m on the 9.69 performance (1.69), not including reaction time, is one of the fastest of all time (faster than Ben’s first 10 1.70 in Seoul)

Good post there is some data on sub 10 elite men and it’s inclusive because of the variation in technique in this group. You are on the right track with minimising flexion in the first few strides but Asafa toe drag is excessive and I think the toe drag does hinder efficiency late in the race.

You are correct Usains world record performances has him faster than Ben and Asafa over the first 20 and 30. Both Ben and Usain are technically better than Asafa, partially because of the higher recovery of the swing leg.

I think the toe drag is just a cue to achieve low heel recovery, not an end in itself. When you look at Asafa’s best races you will see that he doesn’t lose much speed at the end at all. This only happens when he tightens up in the big finals. However, the low heel recovery even at top speed puts a lot of stress on the hip flexors, which is where he has had most of his injuries. Dragging the toe also ruins your spikes, so don’t do it if you’re paying for them yourself. :slight_smile:

I would encourage you to read Ralph Mann’s “The Mechanics of Sprinting and Hurdling” before dismissing Asafa’s technique. His max velocity mechanics in his 9.72 run in Lausanne are what I would argue are the best ever. Ralph has studied virtually all the top US sprinters for the past 25 years, and he has a very clear model of what his data shows is optimal technique. Regardless of what you think of Mann, you should own his book.

I don’t think it is fair to state that evidence of Bolt’s heel to butt technique on pull-through is superior to Asafa’s shin parallel to ground on pull-through. You are talking about two guys with levers of different lengths. If I had to choose, I would choose Asafa’s technique every time over Bolt’s, but I would choose Bolt’s levers. Mann’s data suggests you will save 0.005 per stride with a parallel shin pull-through. Bolt doesn’t need to experiment with this, as he is the fastest.

I will tell you that I have spent time with two elite US coaches in the past year, and they have each incorporated Mann’s technical model with very good results. I can tell you that when Mann initially presented his findings a few years back, there was MAJOR resistance from top US coaches. A few years later, they are all using it. That should tell you something.

With regard to start data and Mann, he found what Charlie figured out 30 years ago: “He who is not on the ground cannot push.” Whoever gets their foot down on the ground to push again first (and whose centre of gravity isn’t in front of them) is going to be the fastest starter. While Mann trashes the jumpstart as inefficient overall (and correctly so- who since Ben has had success with it?), the reality is he espouses the same big picture advice that Charlie did: get back on the ground and push. Ben made the jumpstart work for him because he was back on the ground pushing again while everyone else was still floating in mid-air with their long, slowass pushes.

With regard to max velocity, I coach pelvic neutrality as seen in Asafa’s Lausanne run. I believe an anterior pelvic tilt is not desirable, and everything I do planning-wise revolves around maintaining pelvic neutrality (weight room, etc). Do I have any peer-reviewed evidence? Nope. But science is an inherently conservative field which trails practical experience by up to 30 years, so I don’t have time to wait for that.

T Slow, did you catch Asafa’s 9.84 last week in Jamaica? Very impressive form at this early stage.

Hey James,

Great to see you back posting! I did see his 9.84, and he looks great. He is supposedly training with his brother Donovan full time in Austin, and clearly he knows what he’s doing.

In addition, I was surprised to see Gatlin run a personal best today. I didn’t think he had a 9.74 in him!

See Dr. Pfaff above from 1:30-2:00 in the video.


I notice in Asafa’s latest 9.84 that he did not get off to THIS kind of start:

Powell also ran faster early this season than he did back in 2010 when he ran that blazing start in Rome, so I’m wondering if overemphasis of things like toe drag that are going to have relatively minimal effect on time amount to wasting energy on what Dan Pfaff describes as too rapid acceleration for your genetics that cost you more time later. I think Pfaff is really talking about things like shortening your stride to get the absolute fastest acceleration, but that might not be the only thing that costs you later.

In terms of real numbers, what do you really get from toe drag? And how much energy are you wasting from the biomechanics standpoint?

his brother was a 10.0 sprinter himself

I can tell you of an experience I had on a training camp earlier this year. I had a guy come with me that basically heel cycles right out of the blocks. We found that the time from first motion to first contact was relatively unchanged regardless of low heel recovery or high heel recovery. However, his contact time on step one was reliably reduced by 3 one hundredths of a second with a low heel recovery. Interesting stuff! Play around with it and see what you find. I’ve seen up to 0.10 saved on the first three steps.

“The start is way more important than we thought!” was what I saw Ralph Mann say in December 2013.

Charlie knew that 30 years ago.

Just because CF and Mann differ somewhat on biomechanics (due to the availability of force blocks, and high speed cameras that fit in your pocket) doesn’t mean CF was wrong. He had the key ideas correct (work on accelerating a lot, and get back on the ground and push before everyone else) and his athletes were kicking the crap out of everyone at accelerating way before anyone else knew what he was up to. I mean in Seoul the race was literally over at 3 metres- and this fact is what convinced me Mann was onto something.