Acceleration

I utilize a notecard system to help me organize similar material I come across from various resources. My intent over the next few years is to share and continually update these notecards with you.

This notecard is all about building the essential quality of acceleration.

Acceleration Mechanics

Effective acceleration relies positioning the body to maximize force application into the ground.
“The ground is the well from which you draw speed” ~Dan Pfaff
There are three keys to acceleration:
  1. Rhythm – pace and steps should follow a crescendo (like a slow clap).
  2. Rise – There should be an incremental rise in center of mass (like an airplane taking off)
  3. Projection – the system continues to go forward1

Trunk Mechanics

The most important key to accelerating well is a fast and large first step2. It is this first step, and the distance gained from the first step, that initiates the desirable acceleration crescendo.

Keeping the body and shin angle at 45 degrees allows horizontal and vertical forces to merge in a manner that is necessary for acceleration2,3. If short, choppy steps are performed during this phase, then less force is applied into the ground.

Notice the body lean, the shin angle at 45. Yohan can accelerate, fam.

Lower Extremity Mechanics

The leg and toe should stay low to generate push-off in the first few steps, though this is not something we wish to cue4. Some sprint coaches will cue dragging the toe to reinforce position, but this strategy is undesirable. Toe drag increases friction and slows the athlete down2.

Equally problematic is staying too low. If below 45 degrees, the athlete will step laterally instead of forward, simply because staying too low minimizes hip flexion range of motion2.

The feet ought to stay relatively underneath the body during acceleration. If legs begin to reach out in front of the athlete, the athlete will then slow down. Feet under the hips are accelerators, whereas feet in front of the body are brakes5

Upper Extremity and Neck Mechanics

From an upper body standpoint, the head and shoulders ought to also stay low, or the body will upright too early4.  As the upper body rises, the chest should be visible before the chin1.

Upper body is in a relatively straight line with the rest of the body. Arms are pushed forward and out

Early uprighting is typically related to reduced power output, sport-skill induced (e.g. a football lineman), or a potentially a neck issue6,7.

Arms ought to reach forward and out with each step. These mechanics are called frontside mechanics. This arm action reduces excessive backside mechanics (i.e. arms fall too much behind the body, driving extension) from occurring, which will prematurely upright the body7. Moving the hands first and fast can help create push-off from the backside leg4.

Eyes ought to fixate on a ground point 2-3m ahead of where the individual ought is going. If looking further forward, neck extension will prematurely uprights the individual, diminishing time spent in acceleration3.

Acceleration Energy Systems

Maximum acceleration is alactic in nature, and the longer time we can spend accelerating, the better.
The zone of acceleration is the distance over which one is able to accelerate prior to reaching maximum velocity. In elite 100m runners, this typically constitutes the first 60-80m of the race for males, 40-60m for females; with the bulk of acceleration occurring within the first 30m3.
If one can make their zone of acceleration longer and faster, we can prolong shifting to lactic metabolism as the primary energy system. Glycolysis, the reaction of lactic metabolism, is a slower energy reaction than the ATP-CP reaction of alactic metabolism. Longer time to produce energy begets slower outputs and likely fatigue3. As fatigue sets in, increases occur in ground contact time, amortization, and flight times2.

Measuring Acceleration

 Fully automatic timing (FAT) is recommended as a measure when training acceleration, simply because the margins for improvement of this quality are minor3.
An example of a FAT camera
The error for which hand timing creates is astronomical. You roughly have to add 0.4s to each run to account for this error; 0.24s for basic error, and 0.13-0.16 for reaction time on the start/stop3.

Acceleration in Sport

When not starting from the blocks, an individual still positions oneself in a manner that emphasizes acceleration angles. This maneuver is called a repositioning step. The repositioning step is not a true step, but a drop into a position that allows for effective acceleration6.

 As you can see in the above video, these athletes utilize a repositioning step to drop their center of mass at an angle that allows them to effectively propel themselves into the desired direction.

Training Acceleration

There are many modalities that can be used to drive acceleration mechanics. Here are some of the common methods espoused by various coaches.

Hill sprints

Keep the incline at 5-10%3.
Here is a video of the Jamican sprinter Yohan Blake hitting these up

 Sled Sprints

Resistance allows you to remain in acceleration longer, thus can be a useful modality to train this quality4.
Adding resistance cannot conflict with decreasing ground contact time or increased flight time that occurs with progressive acceleration, thus only add as much weight as form allows2,5.
Sled pulls offer the edge of allowing arm actions to drive proper acceleration mechanics
Whereas pushing a prowler maintains the acceleration angle throughout.

 Prone Starts

 The step up from prone allows for emphasis on acceleration push-off3.
Though the guy above doesn’t get as much forward arm reach as I’d like, his first step into the acceleration position is money.

 Supine Starts

Supine sprint starts are another great method to train acceleration, and may be especially useful in team sports for recovery after a fall3.
With this cat in the above video, I would like a larger first step, but he maintains a good acceleration angle without too early of a rise.

External Cue Sprint

Placing an object in front of the client that he or she must aim to sprint through can help create a larger first step. Ball drop activities can be useful in this case6.

 Falling Starts

This technique can be utilized to encourage a large first step. A large first step is a reactive action that occurs to prevent the fall.

Typically, this drill was done being from an upright start, but the tendency for early rise and backside mechanics is much higher with this starting position. A better drive angle can occur if the client starts in a low position7:

Acceleration Technique Drills

If you want to improve specific aspects of acceleration that cannot be achieved with coaching or training, implementing drills can be a useful way to break the acceleration skill down into its specific components.
For lower extremity mechanics, a wall drill is commonly used. Here are the components necessary to perform the wall drill successfully:
  • Start at shoulder height with the wrists
  • Body is in a straight line
  • 90 degrees hip flexion
  • heel under hamstring
  • Piston up/down emphasis6

That said, cleaning up arm mechanics oftentimes takes care of any inefficient leg mechanics, and is much easier to coach7. Since the wall drill fixes the arms onto the wall, the transfer amount to acceleration is questionable.

A perhaps better alternative could be a low box drill, which both allows for arm drive and places the athlete at an appropriate angle6.

Programming Acceleration

Acceleration can be addressed daily because it is a skill. Volume must be modulated accordingly to prevent overtraining and maintain power output8.
A typical session could be 3 series of 5 sets of 10 m (3x5x10m) with 60-120s of recovery; keeping a total volume of 150-350m pending the sport7. Building up volume over time, especially in team sports athletes, may allow for better sport skill performance come end-game7.
Since acceleration is an alactic endeavor, distances trained ought to reflect the point where maximum velocity is hit. Once maximum velocity is hit, acceleration is over2. Capping the durations at 6 seconds is a prudent way to achieve this goal3.

In an overall progression of things, many coaches favor the short to long method. That is, starting with shorter runs, then slowly increasing the distance of one run over time. A recommended acceleration-focused example of this would be starting at 5m and working up to 20m accelerations3.

Supportive Exercises for Acceleration

Quarter squats at submaximal load and/or Olympic lifts are effective exercises to incorporate when performing acceleration training. Single leg jumps and throws with a similar (<80 degree) knee bend are also effective3.
In regards to weight amounts, absolute strength (>90% 1 repetition max) will help with improving the first two steps, whereas power training (fast accelerations, 20-50% 1 repetition max) helps with the first eight steps2.

Sum Up

While far from exhaustive, the references that I have had the pleasure of learning from have taught me a great deal in regards to training and improving acceleration, and have helped me quite a bit with improving these qualities in my clients.

To summarize:

  • Effective acceleration relies on force application into the ground
  • Acceleration stops once maximum velocity is attained
  • Maintain a slow, low rise upon increasing velocity
  • Cueing arm forward and out arms actions is a simple and effective way to fix most acceleration errors
  • Distances and durations for training acceleration ought to be short

Which techniques and resources do you draw from to cue acceleration? Comment below and I can add to this notecard.

References

  1. Stu Mcmillan. Altis Apprenticeship Coaching Program. 2016
  2. Dan Pfaff. Altis Apprenticeship Coaching Program. 2016.
  3. James Smith. Applied Sprint Training, 2014
  4. Lee Taft. Physical Preparation Summit. 2012.
  5. Mike Boyle. New Functional Training for Sports. 2nd edition.  2016.
  6. Lee Taft. Certified Speed and Agility Coach. Online. 2016
  7. Derek Hansen. Private Seminar. 2017.
  8. Buddy Morris on the Physical Preparation Podcast. 2015. 

Photo & Video Credits

Nick Webb 

Darren Wilkenson

Andrew Hecker

Mart Muru

Original B&E

Barbell Shrugged

Mountain Tactical Institute 

Melina Karamitros

Kevin Carr