What is Acceleration?
When you look at acceleration, we're looking at a change in velocity. That change in velocity could be big or small. So we're looking at how the object accelerates to top speed.
A lot of people think about acceleration as a certain distance people accelerate to. But acceleration is literally everything leading up to top speed.
So a high acceleration rate means that there's a big rate of change in speed or velocity. At the beginning of a sprint, there's a high acceleration rate because you're going from almost zero velocity to a higher velocity.
We know that an athlete can reach 40 to 60% of their max speed in 2-4 steps.
Going from 0 to 60% in four steps is a high acceleration rate. If you look near max speed, maybe at the 20 or 30 yard mark, an athlete might go from 18 to 20 mph. That athlete is still accelerating from 18 to 20, just not as high of a rate of acceleration.
So when you think about acceleration, think of everything leading up to top speed.
Your acceleration phase is done once you reach your maximum velocity.
How to Improve Acceleration?
In order to improve an athlete’s acceleration, we know there are physical buckets that need to be filled in order for that athlete to be able to accelerate well.
(If you want a review on the 3 buckets of speed)
The first physical bucket an athlete needs is the ability to produce high amounts of force in relation to their body weight.
If an athlete can produce high percentages of force for their body weight, we know that they have that bucket filled.
For the second physical bucket, the athlete needs to be powerful and reactive.
If an athlete can produce 3-4x their body weight into the ground, and I know that’s a quality I’ve tested either on force plates or in the weight room then I know that athlete is strong.
But if they can’t apply that force fast, they’re lacking something called impulse.
Impulse is how much force I can produce and how much time. So a high impulse means it’s a high force and low time. A bad impulse would be a medium or low force in a long period of time.
So for sprinting, even in acceleration, the contact times are very fast and we need to make sure that the athlete can apply those forces very, very, very fast into the ground.
What specifically do we do to improve this?
We’re looking at the ability to move light weight fast, medium weight fast, or be reactive with things like jumps, plyos, reactive hops, and those types of movements.
From a physical standpoint, athletes need to be powerful and reactive, AND they have to have the ability to produce high amounts of force in relation to their body weight.
What about from a technical standpoint?
Technical Qualities to Improve Acceleration
On the technical side, there are 3 capabilities we look at:
Projection can be broken into two categories with the torso being the first.
If you’ve heard my YouTube videos, I talk about the torso torpedo, or being able to shoot your torso forward. (example of me talking more in depth)
It’s not just straight ahead, but up and out as far as possible.
The second thing we look at is hip projection. Can the hip actually go from stance and travel about a yard forward?
If you don’t have torso and hip projection, it’s going to be very hard to have good acceleration, especially at the beginning.
Next is switching.
Once the athlete has projected their body and created distance from the start line, they need to be able to switch their thighs back.
When the thigh is as high as possible in the front, can it be reversed quickly to be able to create a high impact into the ground?
From switching, we get negative foot speed. If my leg is traveling backward, the other leg has to travel forward, and that’s what switching creates.
So I'm going to create a high impact or a high force in a short time frame (high impulse) with that negative foot speed while also getting my next leg through for the next stride.
So switching becomes very, very, very important, especially in the first couple of strides, to be able to get the body into a pattern to produce faster velocities.
Finally, the third technical quality we look at for acceleration is called rise.
If I project myself out and I switch and have a low torso, I need my torso to rise every single step.
Every step it should rise incrementally like an airplane taking off.
So as I reach near my max velocity, my torso and my shin angle is going to rise.
The application of force at the beginning of the sprint is going to be down and back - as I go further, my direction of forces is going to become more and more vertical.
By step seven, I should have more of a vertical shin and be attacking down, whereas my torso is going to continue to climb after step seven. We call it rise.
The last component that ties into rise is rhythm. If you run correctly, and you run through an effective acceleration, you’re going to have a crescendoing response to how you produce forces into the ground.
The beginning will start very slow, and then it’s going to start to get very, very, very fast as you run.
Each step should crescendo and your rhythm should get faster as you climb towards max velocity.
Those are the key components of improving acceleration. I’ll leave you with one great drill that can be used to improve acceleration that I’ve talked about before called the 7-Step Projection.
If you want a deeper dive into acceleration, including how to use Load Velocity and Force Velocity Profiles, check out my course, Art of Acceleration.