⚡️SSL #020: Are you Speed or Force-based?

Dec 18, 2022

In today's issue of the “Saturday Sprint Letter,” I’m going to discuss how to find out if you are lacking pure speed, or lacking absolute strength.

The problem with sprinting is there are so many ways to improve your speed.

Heavy strength training. Olympic lifting. Plyometrics. Sled Work.

The list goes on.

One solution is to use a Force Velocity Profile.

By figuring out where you are on the spectrum between speed and strength, you can learn how to train more effectively.

For example:

Athlete A is powerful and explosive but lacks top-end speed.

Athlete B is very bouncy and fast but lacks explosiveness and therefore struggles in their start.

Specifically I’m going to talk about:

What is The Force Velocity Curve?
What It Tells Us About Sprinting
What is Force Velocity Profiling?
How To Create One

Let’s dive in.

#1 What is The Force Velocity Curve?

Look at the graph above.

One side represents velocity, we can think of this as how fast you’re moving.

The other side represents force, we can think of this as how much strength you’re using.

This line represents the relationship between moving very fast and producing high amounts of force.

It’s known as the Force Velocity curve.

Think of a 1 rep max squat on one end of the curve.

The forces are high and velocity is slow.

On the other side, we have max speed sprinting.

The horizontal velocity is high, but the horizontal forces are low.

This concept applies to other movements besides sprinting, such as lifting and jumping.

#2 What It Tells Us About Sprinting

Specifically, on one end of the curve is the sprint start.

The horizontal velocity is low and the athlete puts high amounts of horizontal force into the ground.

Then as the athlete accelerates, their horizontal velocity increases...

And the amount of force being applied horizontally decreases.

Which we can see as they become upright.

In order to improve our acceleration and run faster, we just need to find out where along the curve we suck.

This is done through force-velocity profiling.

#3 What is Force Velocity Profiling?

It’s important we understand this:

Force X Velocity = Power.

According to science, the more horizontal power an athlete has, the better their acceleration will be.

Force velocity profiling helps you figure out whether you should focus more on getting stronger (FORCE), or on improving your speed (VELOCITY).

Fixing the weak area = increasing your horizontal power = accelerating more effectively.

That is what a force-velocity profile reveals.

#4 How To Create One

Previously, you needed expensive lab equipment to do this assessment.

Fortunately, in recent years researchers have outlined a method that doesn’t require much equipment and uses a mathematical formula.

Rather than explaining the details of how it works, you can look at the research paper from the scientist themselves: [Study]

To perform the test you can use this spreadsheet to calculate your results for free:[link]

Essentially it requires you to measure your 5, 10, 15, 20, 25, and 30m splits.

On the other hand, if you want to skip everything like me you can just get the Mysprintapp.

It costs a few dollars, I’m not affiliated and don’t make money from it but it’s a faster and easier option.

It’s been validated as a reliable way to measure your force-velocity profile according to this study. https://pubmed.ncbi.nlm.nih.gov/27806673/

That being said, if you’re running above a 5-second 40-yard dash, or above 12 seconds in the 100m, then this might be overkill.

In that case, you don’t need this level of data, you just need to sprint 2x per week, and follow a good program.

TL;DR

A Force Velocity Curve represents the relationship between moving very fast, and producing high amounts force.
In order to improve our acceleration and run faster, we just need find out where along the curve we suck.
Force velocity profiling helps you figure out whether you should focus more on getting stronger (FORCE), or on improving your speed (VELOCITY).
That being said, if you’re running above a 5 second 40 yard dash, or above 12 seconds in the 100m, then this might be overkill.

Stay Fast,

Cesar

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