Pole Vault Coach Wisdom: Fact or Myth?

Bubka makes things look too easy. Running while carrying a pole (over two times one's height) presents some elemental difficulties. Yet, Bubka manages to do it for a total of twenty steps, as evidenced in the video in the previous post.


In pole vaulter world, this epic run is not spoken of in terms of total steps. We count the number of times the left foot takes a stride. Bubka took twenty steps, but a pole vaulter would say that he vaulted from a ten-stride.


At the high school level, girls at the competitive state level usually run from around a seven-stride. This may not sound like such a big difference to the layman ("Seven is almost ten, right?"), but a coach once told me that every one increase in stride means vaulting a foot higher. And that's a gargantuan difference in a sport like track and field, where records are beaten by milliseconds or half inches.


It still seems a bit unbelievable, however, that a mere two steps would catapult the vaulter an entire foot higher. But we've already found how a vaulter's velocity relates to the height he can vault. So let's calculate if this really is true.


Two running steps is about 11 feet for the high school female, believe it or not (when my coach tells me to go from a six-stride to a seven-stride, he tells me to go back 11 feet). I would estimate two of Bubka's steps to be about 15 feet, or 4.572 meters.


We calculated in a previous post that Bubka's final velocity is 11.0 m/s. Based on the video of his record jump, his total run is timed to be about 6 seconds. This gives us enough to calculate his average acceleration.

a = (v₁ - v₀) / t
a = (11.0 m/s - 0 m/s) / 6
a = 1.83 m/s²


Of course, in real life, Bubka's acceleration wouldn't remain constant throughout his run. His acceleration would be very high in the beginning of his run, and as he approached his maximum speed, his acceleration would decrease. However, for the purpose of estimation, let's assume that Bubka's acceleration does remain constant.


v₁² = v₀² + 2ad
v₁² = (11.0 m/s)² + 2 (1.83 m/s²) (4.572 m)
v₁² = 137.733
v₁ = 11.736 m/s


Bubka's final velocity if he had run one stride more would be 11.736 m/s. How high would he jump?


v = √19.62h
11.736 = √19.62h
137.733 = 19.62h
h = 7.02 m = 23.03 ft


So is it possible to increase vaulting height by one whole foot by adding a stride? Yes, yes it is. By adding a stride to Bubka's world record vault, we calculated that he could vault almost three feet higher. Remember, however, that we estimated Bubka's acceleration to be higher than it really is, for ease of calculation, so in reality, a one-stride increase would probably bring the vaulter about one foot higher.


And now you should have mad respect for pole vault coach wisdom. But you may be asking yourself, why didn't Bubka just run from two steps back? To quote one of the best coaches of all time-- "If pole vaulting were that easy, everyone'd be good at it."

Bubka in Action

"We do sprint training."

A common question I'm asked by my curious peers is: "How do you train for pole vault?" I used to give them a detailed summary about how I drive out to train with this other coach in that other far city once or twice a week, and how we do "bar work" and do drills.

However, after pole vaulting for a few years now, I've boiled down my answer to: "We do sprint training."

Why is sprint training so important in pole vault? Sure, it takes no-nonsense abdominals to perform those top-of-vault contortions. And it takes gnarly arm strength to prevent the pole (your "friend") from performing a blunt and glorified back-stabbing. Despite the blatant importance of upper-body strength, pole vaulters spend the majority of time training to run faster.

There is wisdom in this.

Observe this complex diagram.

The pole vaulter of mass m runs with velocity v to clear height h.

And also, recall the equations for kinetic energy and potential energy.

Kinetic Energy = ½mv²

Potential Energy = mgh

In a simple world, the vaulter's kinetic energy equals his potential energy.

m = mass of vaulter
v = velocity of vaulter when he plants the pole
g = acceleration due to gravity (9.81 m/s²⁾
h = height of crossbar

½mv² = mgh
v² = 2gh
v = √2gh
v = √19.62h

Thus, a pole vaulter "can vault only as high as he can run."

How fast was Bubka running into his world record vault?

The Bubka-beast.

v = ?
h = 6.14 m (20.2 ft)

v = √19.62h
v = √19.62(6.14)
v = 11.0 m/s (24.6 mph)

That's pretty amazing-- Can people even run that fast?

Usain Bolt holds the current world record for the 100 meter dash. His top speed is 12.2 m/s (27.3 mph).

So yes, people can run pretty fast, and Bubka is, in fact, as fast as a world class sprinter (keep in mind that he has to sprint while holding a fifteen-foot pole).

A Certain Brand of Character, Eh?

They say that it takes a certain brand of character to pole vault. A certain brand of character to carry a hefty, ten-foot-some pole, book it like a criminal down a runway, and fly up to the height of a two-story window. Yet, despite the craziness, pole vaulting works. The world record is a whopping 6.14 meters (about 20 feet, 2 inches), held since 1994 by the formidable Ukrainian, Sergey Bubka.

So what makes it possible to soar to new heights with nothing at hand but a carbon fiber pole? The idea behind pole vault is the conversion of kinetic energy to potential energy-- the vaulter turns kinetic energy (horizontal ground speed), into potential energy (height). As for how the pole assists the vaulter with this...

A picture is worth a thousand words...

Of course, the diagram is missing the part in which the vaulter plummets back to earth with an acceleration of 9.81 meters per second squared (gravity), but that part is slightly more self-explanatory.

The above freeze-frame diagram illustrates the progression of the vault and how the pole bends and unbends to catapult the vaulter up and over the crossbar. The dent that the vaulter sticks his pole into is called the box, and in real life appears like so:

Yes, technically, the box isn't actually a box. It's a slightly trapezoidal indentation in the ground that consists of a sloping bottom and a vertical back wall to stop the horizontal motion of the pole... cold turkey. The box is eight inches deep, which is sometimes loved and sometimes hated by pole vaulters... Loved when 10 feet high is actually 10 feet 8 inches, and hated when the airheaded vaulter receives a thorough ankle-spraining.

Stay tuned, and light will soon be shed on the many remaining mysteries of pole vaulting.