4.6 Force Application

Athletic speed is the most revered skill in the sporting community. In fact, the science of speed is far more mysterious than improving strength, endurance and mobility. Parisi coaches dedicate a large amount of their time teaching the skill of speed. It is required that Parisi coaches understand the different kinds of speed. The Parisi system separates them into maximum velocity, acceleration and multidirectional speed. While Parisi classes offer curriculums that address each of these goals, the underlying theme for all athletic movement is force application. In order to become faster an athlete must apply more force into and off the ground both vertically and horizontally. As an athlete increases their force application, it must be performed in the same or shorter amount of time, and at the same or lighter body weight, in order to improve overall speed. Understanding how to apply force, and in the proper direction, is referred to as the “expression of force” or “force expression”.

Athletes will express force differently based on their body type and physiological make up. Physiological systems such as the skeletal, muscular, nervous, fascia-connective-tissue, and lymphatic all play an important role in how an athlete expresses force. An example of this would be an NFL defensive back compared to an NFL tight end. They both are fast athletes but their body types and force producing systems work differently. The defensive back has less muscle mass compared to a tight end and therefore relies more on the fascia-connective tissue of the tendons to produce force compared to the tight end who relies more on muscle producing force. This example would be even more extreem if we compared a wide receiver to an offensive lineman.

The expression of force is something that’s unique to the individual. When sprinting you should not hear a loud pounding on the ground. Fast athletes run quietly and take advantage of the elastic elements of the muscular-skeleton-connective-tissue systems. The amortization phase of each ground contact is unique to the individual. Not only does muscle and connective tissue forces play a role in the ground contact time / amortization phase, but so does hydration, or the lack of thereof, recovery-quality of the nervous system and its ability to send responding impulses. The human body is an encapsulated pressurized hydronic system that responds like one big overall Bio-Tensegrity spring model. This is where all the bones are defined as compressive forces and are held together and connected through elastic tension forces which are defined as the tendons and fascia.

Picture Olympic Gymnast Simone Biles who weighs 104 lb and the fastest defensive linemen at the 2020 NFL Combine, James Smith-Williams who weighs 264 lbs. These two amazing athletes are polar opposites in their body types and even sports. However, they are both masters of force application. Smith-Williams ran the 40 yard dash in 4.6 seconds, reaching approximately 24 mph and is also able to perform a 40 inch vertical jump. Biles executes a triple-double tumbling pass with a launch speed of over 13mph. Her sprint distance is about one-third of the 40 yard dash before she projects into the air for about 1.18 seconds of hang time. Their training integrates their sport-specific skills with strategic exercises and mechanics to constantly improve their mass-specific force application. Despite the difference in their mass, gravitational acceleration (-9.8/m/s/s of downward acceleration) remains a constant variable that all athletes must contend with throughout their athletic careers.

High speed running is the closest humans get to flying. It is this human endeavor that inspires so many Parisi speed coaches. Teaching the skill of force application requires a combination of teaching the biomechanics of the sprint, which happens on all three planes of motion. Even though in maximum speed running the force is primarily being applied vertically and then slightly horizon- tally at toe off, the body must do so in harmony. By investing class time into understanding and training force application you will improve the stride length and frequency of your athletes. This will ultimately make them faster.

The Parisi Speed School has always had a big picture point of view when managing their athletes. As industry leaders in performance enhancement our goal is to increase each athlete’s potential for speed while mitigating the risks for injury. Force application is a critical part of all types of speed training and development. Mass-specific force guides many of our speed training strategies. Mass is often overlooked as a key variable to the speed training equation. To best understand why, think about the fact that all movement is gravity-dependent. It must be overcome. The heavier you are, the more force you must apply to the ground. Parisi coaches must understand how to guide athletes towards a strength training program that ultimately enhances their mass specific force application potential.

According to the Anatomy of Speed, by Bill Parisi, “ The manifestation of speed is at its core the process of overcoming gravity by harnessing energy with every part of your body and directing that force at the ground to efficiently propel yourself in a specific direction through space and time.” Parisi classes will always be filled with a wide variety of youth athletes. Some of them will become the future generation of world class swimmers, gymnasts, sprinters, football players and goalies.

Parisi coaches always deliver a positive training experience using our signature speed and strength curriculums, setting everyone up to succeed. We accomplish this by learning how our many mechanical drills and their application improve speed. Exercises like pogos, straight leg bounds and wall drive are key mechanical drills within the Parisi system that enhance force application. These movements anchor our athletes and apply to all ages. These promote an understanding that force application relies on several mechanical facts:

  1. Muscle stiffness is important. The muscles, fascia and joints act like springs. Stiff tendons transfer force more rapidly.
  2. Leg stiffness increases vertical impulses which in turns shortens ground contact and increases the elastic return.
  3. Short ground contact time leads to increases in speed.
  4. Hip extension or “hip lock” promotes an athletes ability to apply more force into the ground.
  5. Leg recovery relies on a whip-like re-cycle of the leg which travels through hip extension and then attacks the ground with massive ground force before the next stride.