It has been often attributed and debated that there are 2 key factors an athlete should increase if they wanted to sprint faster.
The main 2 factors believed to contribute to faster sprinting speeds were:
1 – Stride Length – The distance between foot contacts
2 – Stride Frequency – How many foot contacts are made
As science and critical thinking and the research of Peter Weyand from Southern Methodist University conclude in this video that neither of those two factors are the cause of faster sprinting speeds, but rather the effect of increased force production into the ground.
The simple translation is this…the higher level athlete who sprints faster is able to apply more force by striking the ground harder!
Now before you go “stomping” around thinking you’re sprinting faster let’s dig in a bit deeper for better application.
On the graph’s Y-Axis (vertical) showing 100-800 is showing how much force is being applied in pounds.
On the graph’s X-Axis (horizontal) showing 0 – 0.25 is how long it takes for the force to be applied in seconds.
In this study they used 100m and 200m track and field sprinters which are represented in the black line shows the faster athlete with a higher force output (roughly 750 pounds) in roughly .16 seconds.
While the red line shows soccer, football and lacrosse athletes which were slower in comparison with a lower force output (roughly 650 pounds) in the same time frame of .16 seconds.
So the athlete who can produce more force, especially in the same time frame or less will be the faster athlete.
While this is a glaringly simple idea to comprehend what’s really going on here is this….
He’s applying 750 pounds of force in .25 seconds!
That’s kind of like this strong animal Brandon Lilly deadlifting 755 pounds raw
Real quicly do this > Take out your phone out of your pocket and open up stop watch
Now, I want you to tap as quickly as you can the “start” – “stop” button,
How long did it take?
The blink of an eye? That’s the same time frame it took this athlete to produce 755-pounds of force!
I timed Brandon Lilly’s deadlift and it was a bit under 2 seconds.
> That’s generating the same amount of force, but 12x faster! <
PLUS if that is not enough, the sprint athlete generated that 755 pounds of force while on one leg…BOOM!
I couldn’t find a 755-pound single leg deadlift by the way because sprint forces cannot be duplicated in the weight room!
Now that your mind is as blown as mine and we are in awe of what’s truly happening while athletes sprint and we know that Speed Is King!
The athlete must be able to generate, withstand and deliver forceful foot contacts to propel themselves at top speeds.
They do this by:
“They cock the knee high before driving the foot into the ground while maintaining a stiff ankle. These actions elevate ground forces by stopping the lower leg abruptly upon impact.”
Peter Weyand, director of the SMU Locomotor Performance Lab
The higher the athlete can overcome gravity, raise their COM (center of mass aka hips), the more potential they have to deliver a forceful hammer of hip and knee extension down on a stiff ankle joint to the ground.
I’ve heard it best put by Coach Nick Winkelman saying:
“Think of the thigh as a hammer, and your lower leg as a nail. The higher you pick the hammer up, the more forceful blow you can deliver to the nail”
Same is true if you think about punching, if you want to punch someone, you cock your arm back for a more forceful swing, if you only pull back half as far, you limit the force or how hard you can hit.
The researchers dually noted what makes these athletes speed elite versus others is:
“We found all the fastest athletes applied greater ground forces with a common and apparently characteristic pattern that resulted from the same basic gait features, What these sprinters do differently is in their wind up and delivery mechanics. The motion of their limbs in the air is distinct; so even though the duration of their limb-swing phase at top speed does not differ from other runners, the force delivery mechanism differs markedly.”
The athletes who sprint faster are able to deliver a more forceful punch to the ground while maintaining a stiff ground contact which limits leaks of energy for each foot strike.
If the athlete strikes the ground with a “soft” strike such as toes pointed down instead of up, or too much knee flexion that energy will be lost causing power output to be dumped and reduced when it needs to be re-directed from the ground reaction forces (when the force travels back up the leg and gets used for sprinting faster).
Lastly to wrap up in a more visual sense is to check out this video from Scientific American
Are running speeds maximized with simple-spring stance mechanics?
A Visual Guide To Running Like An Olympian, Scientific American