Step 1 is the first of the many barriers we will encounter on our journey. It isn’t a true physical barrier, but more of a speed barrier. 3.0 m/s second would be that barrier—from my data on the 1080, that is the speed at which enough momentum has been generated to set up a proper first step. That is the speed that should project the body about .5m (I am measuring that with my 1080 equipment).
The reason why a “speed barrier” exists is that if an athlete is slower than 3.0 m/s in their first step, the body will not have the velocity to create stability. So, in order to create stability, the body slows down and puts the first step in place that prevents a fall. Watch someone learning how to ride a bike—without the initial velocity or push from a parent, they wobble and sometimes fall. The body reacts the same way. It will move in ways that create stability before allowing for performance. The easiest way to gain stability is to stand up. Or, do the opposite, lowering the center of mass—this is where you may see an excessive lean or an athlete pushing their hips behind the contact point. Both of these are the neurological responses for stability.
The reason why a ‘speed barrier’ exists is that if an athlete is slower than 3.0 m/s in their first step, the body will not have the velocity to create stability says @korfist. Share on XSo, before drilling all the different techniques that may or may not help the athlete reach the speed barrier (usually not), get physics on your side and hit that velocity, see how it works.
The Exciting Force: Next Steps in Acceleration
Let’s say you get to 3.0 m/s. We can now progress into the action of the story. Step 1 hits at about .5m with the foot underneath the center of mass with a rigid ankle. A good measurement is checking where the hip is in relation to the first foot contact. If the athlete reaches too far, the center of mass won’t project as much. I stole this idea from Coach Neel in Austin TX as a good way to measure actual placement. This also gives a good cue for the athlete to see where they are. Another consideration—too far in the initial landing spot usually sets up a really short second step. So, there is a sweet spot.
Back to the story. The foot hits and the athlete has projected out to .5m. The body has to deal with a vertical force while trying to push horizontally. The added vertical force creates a new barrier: the leg. In fact, it becomes a barrier for every step. An athlete has to move their center of mass (hips and torso) 60 degrees over a fixed point (leg) while getting pulled into the ground. If we take a 3-frame shot, this looks like the athlete is pulling their hips past their foot.
An exercise to strengthen this would be a simple resisted run. But most of the time, untrained athletes can’t find that position with a heavy weight around their waist. They tend to bend and lose the shin/torso relationship, and it becomes a different exercise. This is why I like Yuri’s. I can position their foot and torso in a position and pull their hips forward. Or, I can reverse the Yuri and use a cable with a foot strap around the ball of their toe, having them push back. This will force the athlete to keep a rigid ankle.
If I wanted to add a vertical component, an athlete can also add bands over their shoulders as well. Or, we can add an inter-thigh component and band up the opposite thigh as well.
Video 1. This is the basic Yuri, where the athlete has to pull their body across the band.
Video 2. Adding more to the basic, the HF requires more inter-thigh action using the hips to help the movement.
Video 3. Adding vertical pressure forces the body to deal with a vertical overload in addition to 2 horizontal forces.
What muscles are working? What needs to be Sprint Strength. In 2021, the Scandinavian Journal of Medicine Science Sports published a brilliant paper entitled “How muscles maximize performance in accelerated sprinting” by Marcus Pandy, Adrian Lai, Anthony Schade, and Yi-Chung Lin. Measuring 19 foot strikes, they wanted to determine what muscles were working. The paper is a gold mine of information and warrants multiple readings. But, to sum it up: gastrocs, hamstrings, and glute medius need to be strong.
Gastrocs ideally contract from a plantarflexed position. While the Soleus offer vertical lift, the gastrocs need to create torque. This means that instead of raising vertically, like in a traditional weight room calf exercise, gastrocs will rotate the heel forward over the ball of the toe. Imagine a socket anchored on the ball of your big toe, your gastroc is what rotates the socket from a horizontal position (9 or 3 on a clock) to noon. Below is a good example of how to create torque in your gastroc exercises.
Video 4. Torque Calf Raise.
The hamstring involved in these early steps is the long head of the biceps femoris. This hamstring is the muscle that brings the foot into the ground. In fact, this is the hamstring that brings the leg into the ground throughout the entire sprint. The faster the leg goes into the ground, the faster an athlete runs… thanks Ken Clark. This movement is what creates tangential velocity.
The problem for this muscle on the first step is the bend in the torso. This position stretches the long head of the biceps femoris to its furthest position, which is why so many hamstring injuries occur in these early acceleration steps. How can we strengthen this position? Use a cable machine to pull down with your leg. Postural changes will change the exercise (Side note: in the next article, I will write more about hamstrings).
Video 5. Simple biceps femoris pull.
One would think the glute max would be next in the importance for the recruitment during the early steps in an acceleration. Controversially, at this point, research shows that the glute max helps to raise and stabilize the torso. Surprisingly, it is the glute medius that slides in for their number three spot for muscle recruitment during the early accel stages. More specifically, the posterior head of the glute med. Traditionally thought of as a hip abductor, the posterior head also extends the hip with the foot turned out. And, as mentioned in a previous article, if one end of the joint is locked, it will bring the other side forward. In this case, it will bring the opposite hip forward. The hip flexion will help create space between the peak hip flexion point and the ground, so the limb has extra time to accelerate into the ground.
An easy exercise is to get in an accel position and pull your swing thigh forward, forcing the rotation of the hip. I like to use a box to emphasize height in the swing leg.
Video 6. Low HF 2 Ways: focus on the far athlete.
Where are the traditional weight room exercises? They can help, but a problem arises when we flip the frames from the earlier trio image on the side and you can see what we are trying to do.
He pushes with his shins, staying parallel with his torso. He gets his horizontal force by rolling shins down. In the weight room, most machines deal in a vertical aspect, where novice athletes lose that shin/torso relationship. This is a hard pattern to replicate in a gravity-driven environment.
Another aspect of the accel phase that is worth noting is the frequency at which the legs cycle. After logging thousands of runs on the 1080 Sprint, I have found that really fast people have a high rate of turnover in the early stage of the run. One paper showed Usain Bolt having a frequency of 4.8hz in the first 10m of a 100m. Christian Coleman and Su Bingtian in 2018 were hitting about 4.6hz in the first 3 steps. An average HS sprinter is about 3.8hz. A simple coaching cue would be to focus on turnover when accelerating.
Moving on from acceleration, the next chapter in our story will be about top-end speed.
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