The Run-up Acceleration

[agapit]

You have been told many times to accelerate your run at the end of the approach. You have been taking it on faith. Let me tell you why you should do it!

This is the original explanation copyrighted, trademarked, staked, spit on by me, your humble servant, agapit.

There are three reasons to accelerate your run up at the end:

Reason #1 (small potatoes)

We all talking about the so called “free pole drop”, the more accurate description of this action would be a controlled drop. The left arm is directing the descent of the pole into the box with however small resistance force. The better the technique is the smaller the force required.

To compensate for this small force and keep our center of gravity at the same level as it was before the drop began we need to have more force from somewhere. This force comes from legs resisting the ground. To avoid vertical amplitude variation of the center of gravity of the vaulter, the vaulter should contact the ground with higher frequency. This is true even when absolute speed of a vaulter does not increase.

Reason #2 (Big Fish)

We are focused on decreasing the time between the takeoff and inversion. The natural interruption that we are dealing with is the “swing” (as I described it in a post “The Swing”). Higher frequency of the run produces a higher speed of the legs in relation to the body of the vaulter. This higher speed puts takeoff leg in the post takeoff pre stretch position faster with the faster contraction (the whip BTB2). This allows us to decrease the time between the takeoff and the inversion. This is also true even when the absolute speed of a vaulter does not increase.

Reason #3 (Big Kahuna)

The jump significantly decreases the absolute speed of the vaulter, due to resistance forces required to generate the vertical speed component. Here again, higher frequency of the run produces a higher speed of the legs in relation to the body of the vaulter. This intern allows for shorter more powerful resistance of the takeoff leg against the ground (during the jump). Well now you are awaken to the fact that this decreases speed loses during the jump off the ground. This is also true even when the absolute speed of a vaulter does not increase.

Go spread the Good News!

[KirkB]

I'm asking a followup question about takeoff speed here, to keep all run speed posts together ...

... RUNUP_SPEED + JUMPING_SPEED = TAKEOFF_SPEED

I think the rest holds true. And yes, JUMPING_SPEED is most often a negative value - but on a short-run vault, maybe not.

The shorter the run, the more likelihood that you'll be accelerating off the takeoff foot (because of lack of speed from the runup). No?

Kirk Bryde

I am sorry to tell you, but unless you are jumpping without run up the jump is always a negative value for the total speed. ...

I need some clarification here. Are you saying that it's physically impossible to accelerate on takeoff even on a short run vault, or are you just saying that it's unlikely, given certain assumptions about the number of steps in the run and the serious intent of the vaulter to run at a speed something close to his max?

The reason I ask is that I used to do a drill where I would jog up to the takeoff, then accelerate on the penultimate stride and into the takeoff. I truly believed that it was a positive acceleration - not just a minimization of braking as I converted some of my horizontal speed to vertical speed.

Then I gradually worked that drill backwards to a 9-step run at more-or-less full speed, retaining my acceleration on takeoff. It took awhile, but I got it to the point where I truly felt I was accelerating on takeoff on my 9-step. Perhaps I was decelerating very little, so it felt like I was accelerating?

Also, compared to other vaulters, my 9-step run was relatively slow, whereas my acceleration on takeoff was very fast. And I worked a lot on takeoff speed (exactly how you and dj talk about), with good success.

If it's impossible on a 9-step, then what about a 7-step or a 5-step?

I just think at some point (some # of steps at a certain RUNUP_SPEED and a certain JUMPING_SPEED), true acceleration on takeoff is possible.

Maybe I'm just hung up on your superlative word "always". Do you really mean always, or just in all liklihood?

Kirk Bryde

[golfdane]

I need some clarification here. Are you saying that it's physically impossible to accelerate on takeoff even on a short run vault, or are you just saying that it's unlikely, given certain assumptions about the number of steps in the run and the serious intent of the vaulter to run at a speed something close to his max?

Kirk Bryde

Point is, that in converting some of your horisontal speed to a vertical component, is energy lost (unless you have a perfect collision with no loss (hypothetical)).

One can have more speed at take-off than your horisontal speed, but it requires a much slower run-up, than what is desired. It requires a solid firing of the muscles (energy input), and a small horisontal component (running speed).

At a full-speed run-up, the energy input from the muscles (active take-off) is smaller than the loss of the conversion from horisontal to vertical.

[agapit]

Maybe I'm just hung up on your superlative word "always". Do you really mean always, or just in all liklihood?

Kirk Bryde

Sorry to confirm this, but you ALWAYS loose speed at at the takeoff, unless you are doing standing jump or maybe one step run up.

[vault3rb0y]

Nice post. Well organized, straight to the good stuff. One question... to what importance would you place run up acceleration compared to top speed into the box? Is it more important to accelerate into your last steps, or is being the same speed into box, but still fast, more important? I ask in relation to the optimimum run length for certain vaulters.

Myself, being a high 16, low 17 vaulter, come from 7 right steps. I accelerate pretty well into the box, but i feel like if i went to 8 steps, i would carry more speed but i wouldnt accelerate as much into the box. Which do you place more importance on? Is there a certain hieght you feel a vaulter should clear or a top speed they should be able to reach before they move their run back farther?

[agapit]

Nice post. Well organized, straight to the good stuff. One question... to what importance would you place run up acceleration compared to top speed into the box? Is it more important to accelerate into your last steps, or is being the same speed into box, but still fast, more important? I ask in relation to the optimimum run length for certain vaulters.

Myself, being a high 16, low 17 vaulter, come from 7 right steps. I accelerate pretty well into the box, but i feel like if i went to 8 steps, i would carry more speed but i wouldnt accelerate as much into the box. Which do you place more importance on? Is there a certain hieght you feel a vaulter should clear or a top speed they should be able to reach before they move their run back farther?

Obviously, the absolute speed acceleration is desirable. The maximum speed at the takeoff is of the paramount importance. But you would benefit from frequency increase even if your speed stayed the same, however increase of speed is always desirable.

[dj]

GOOD MORNING

THOUGHT IT WOULD BE HELPFUL TO POST THIS FROM TOM TELLEZ ON SPEED... THE SAME PRINCIPLES TO CREATE SPEED SHOULD APPLY TO THE APPROACH RUN...

LATER ON I WILL POST CONCERNING THE FIRST PART OF THE APPROACH PRIOR TO THE "SIX STEP POINT"... AND EXPLAIN A "MAJOR" ERROR, I FEEL, THAT TAKES PLACE IN COMPETITION, WHEN THE ADRENALIN GOES UP, WHEN THE GRIP HAS GONE UP, WHEN YOU GO TO A BIGGER POLE..... "B" AND T-MACK MENTIONED AN ADJUSTMENT THEY MADE AT THE 2004 TRIALS AND GAMES AND I WANT TO "DEAL" WITH THAT ADJUSTMENT IN A LITTLE MORE DETAIL

TOM TELLEZ PART II

Common Errors

Stressing stride length or stride frequency?

Debate on the best way of improving sprint speed focuses on two issues:

increasing stride length versus increasing frequency. We are limited physiologically to the amount of strides than can be performed in a second. It is true that most good sprint athletes have just about the same frequency. So, an athlete with adequate conditioning who takes the longest strides usually wins.
Stressing stride frequency alone results in inefficient sprint technique.

Common knowledge portrays stride frequency as a speed advantage. However, stride frequency differs from stride speed. Stride speed is angular velocity of a stride, while frequency is the number of strides, or impulses, per second. Even if a sprinter has the fastest turnover, without proper force application, stride length will be small. This is because frequency alone does cause linear motion; applying force to the ground does. Proper force application results in stride length and frequency increases.

Stride speed is involuntarily increased by the conservation of angular momentum. Shortening the radius, thus reducing the moment of inertia, results in an increase of angular velocity. The shorting of the lever occurs after the foot breaks contact with the ground. This movement is the response of the forces being applied correctly to the ground and is non-volitional.

Illusion of Speed

There is an illusion of speed when then lever does not go through the full range of motion; each movement looks and feels faster. For example if stride frequency is stressed, an athlete may not allow the hip extend through full range of motion to reap whatever benefits he created from applying force to the ground. Lack of hip extension detracts from momentum and ultimately decreases speed because of inefficiency. But the objective is not to move the lever fast but rather transport the mass down the track in the least time possible. Avoiding full range of motion also sacrifices proper force application.

Leg preactivation: pawing action

Pawing action is actually an illusion resulting from rapid hip extension. Too much voluntary action at the knees and ankles causes a reduction in angular velocity of the hip, which is the prime generator of force. Force causes motion while speed is a measurement of motion.
Cyclic force is applied from the hip (radial force) which results in tangential motion of the foot. At foot placement, the shin should be approximately 90 degrees to the ground (Fig. 5). As the center of mass passes over the point of support, the heel briefly touches the ground and the ankle angle closes. This motion puts the Achilles tendon and calf in a stretch position while the knee is bent, allowing a greater push off force from the ball of the foot. Hips extend in one continuous motion from the knee lift position through the end of the push off with no pauses in hip extension at foot contact.

High knee lift

Please see “Knee action” in Part 1.

Reach and Pull

Running action such as reaching and pulling with the hamstrings has been scientifically proven not to produce the most efficient movement (Weyand et. al. 1998). This running style is inefficient because it does not utilize the stretch reflex, but instead requires more muscle forces and volumes per unit of force applied to the ground (Weyand et al. 1998).

Summary

Scientific research across the world has yet to penetrate the track and field world. Athletes can be better sprinters with scientifically proven sprint technique. Better sprinters require coaches who are willing to learn scientific principles as well as a method of communicating their knowledge to the athlete.

more to come later

dj

[dj]

good morning

sorry to put the Tellez info here (it seems to have stopped the thread) but i though it was important to have 'thoughts' of how speed is created so that we can begin to understand what agapit is trying to say..

I agree with agapit and with Petrov's description...

Pretov.. said this about acceleration

Acceleration

Acceleration is the ability to reach the maximum of controllable speed within a certain distance.

An important feature of the acceleration is its increment value and the ability to keep a certain speed on a certain running distance.

Acceleration as an element of the pole vault has its own components which are interrelated and which determine the vaulter’s activity during acceleration. Any changes or disturbances in any of the components will retard the speed and efficiency of the acceleration. The length of the top vaulters’ run-up is on the average about 42-46 m, with 18-20 strides. This length of the run-up provides for the implementation of an athlete’s running abilities and allows for a smooth acceleration.

The 1st part of the approach takes place on a distance usually covered in 4 to 6 strides; it is here that the athlete lays the foundation of the approach:
1. set up of a single system: vaulter/ pole
2. evolving pattern of the first strides
3. run-up rhythm (acceleration), length and rate of the strides.

Maximum speed, its rationality towards the end of the run-up are established and depend on the correctly performed first strides.
It is necessary to stress here that the position of the pole and the vaulter/pole system influence the length and pace in the beginning of the acceleration.

what i would like to do is ask everyone to either post their total run distance (on average) with the number of steps, grip and jump from that run distance...

for example my 6 left (12 step) run is 63 feet and a 12-4 grip...

tim mack was at 9 lefts (18 steps) and 138 feet with a 16-4 grip....

i everyone will send there info either in post or PM i will compile a data base with the mean, media and mode and see if we can "scientifically' arrive at some conclusions on "natural" acceleration patterns...

If possible i would like the first entry on the data sheet to be of bubka... i feel he is the 'standard' we should work from... agapit any chance you have the Meters ( on average) for Bubka's 20 step approach run...

Petrov.......An important feature of the acceleration is its increment value and the ability to keep a certain speed on a certain running distance.

this data may shed some light on the correct way to start a vault form the "first step"... and arrive at the plant with maximum speed........

dj

[dougb]

OK i'll play.

run 120'
18 steps
hand grip 13' 2"
pr 14' 6"
Pole: aluminum Gill

Daughter

run 81'
14 steps
hand grip 12' 8"
pr 12'
Pole 13' #165 spirit, personal weight 135 lbs


doug

[Run2Niels]

A a real golddigger I'm searching through all the posts of Agapit, but I can't find the gem aka the origal post here. Does anybody have a copy of it? Or maybe our dear moderator can find it somewhere?

[KYLE ELLIS]

Are you looking for his Manifesto? If so I think it is on page 2 under advanced technique.

[powerplant42]

No he means the first post in this thread... It's mostly gone!

I remember seeing it pop back up somewhere... I forget where though. I'm 99% sure someone on here has it though.