Updated: May 9
Power is a measure of force over a specific distance. If strength is work against gravity, power is just the same behavior but with speed as a component.
You see it in your daily life. Not just during a power clean or while at training, but in your daily life too. The ability to catch oneself, to recover from a fall, or to grab something with a quick reflex. The ability to produce force quickly goes beyond the weight room and field, but into the realm of normal living. Now the limit of motor unit recruitment differs from person to person. At some point in their life, a person has done this type of muscle contraction, some without knowledge of doing it.
There are a lot of variables that calculate power in the form of watts. To start, we have the equation strength (work capacity = force x distance). Strength is the application of force against an external resistance. Force is a product of the acceleration x mass, a positive rate of change multiplied by the mass of an object. With that, acceleration is the product of velocity x time. And velocity=Displacement of an object x time. So what we are left with is Power (P) = Mass (m) x Displacement^2 (d^2) / Time^3 (t^3).
To keep it easy for my non-physics nerds out there, powers equation is the following, Force x Distance / Time. This simplifies it so we have 3 main variables we work with. We are still moving a certain weight a certain distance, now we add time to complete the rep as another component. Strength coaches manipulate these 3 variables to create a specific adaption that is required for their lifter’s sport or activity. So what are these 3 variables?
1.) How much?
Increasing the mass or how much weight you are moving determines overall power production. For instance, doing a standing vertical jump with a 20 lbs. weight vest is a much different physiological event than without one. Jumping the same height box with and without the vest will produce a different rep each time. Intensity is just one factor when programming for power.
2.) How far?
Another variable to manipulate is to increase/decrease the distance that is needed to complete the rep. Using the same example, we could jump a 26 inch box, then move to a 30 inch box. The only variable that changed was the distance we needed to jump and get on top of the box. Or a blocked power clean. Shortening the distance the bar must travel to be received on the shoulders.
3.) How fast?
This may be the hardest variable to change. There are so many ways to accomplish this. Going back to the same example of a SVJ, we could utilize a tempo jump. In which the athlete slowly squats to their correct jump position and explodes up with a fast tempo. Or We could have them perform a non counter movement jump. They start from their jump position and accelerate up, without throwing their arms back violently. The thing that changed for each of these exercises was the time necessary to complete each rep.
These traits can be trained, so that it is specific to the sport you are playing. We always see pounds on the bar as the main measurement of force production. But with the other 2 variables, deciding what exercises to train for what sports can be difficult. It is also important to consider an injury or condition someone may be training around. We can still train the effects of power, but the stress on our body will differ from lifter to lifter, or athlete to non athlete.
On its face, with all of the equations and explanations, it may seem hard to comprehend. It is easy to overthink, but hopefully this study and example will help you understand it better!
In Gareth Et. Al., the premise of the study was to determine performance of sprinters based on the training of the power clean. They found that hip angles of the power clean are synergistic with hip angles relating to the acceleration phase of sprinting. Power cleans however didn’t show and increase performance in the stride or recovery phase. These are more eccentric in nature, while the beginning of the sprint is more concentrically focused (similar to a power clean)
Notice the torso angle of both athletes. The position of the shoulder over their toes, and their hips relative to their ankles.
The study looked at just training the power clean, and its relationship to sprinter performance. But a well rounded program incorporates the power component with strength as well. You cannot have power production without initial force production as the foundation. Consider the following...
Two athletes are both wide receivers for a football team. One only does power cleans, but the other does power cleans and squats. A power clean is essentially a sub maximal pull from the ground; in which the bar must travel from the floor to the shoulders of the lifter with elbows up, standing upright to finish. The key here being SUBMAXIMAL. Both athletes power clean, but which on is stronger and most likely more powerful? Athlete A trains the power clean weekly and can accelerate his body at a much higher rate than most untrained wide receivers. Athlete B however will accelerate more and stay at top speed more effectively due to his training outside of just the power clean. His general strength is much higher than athlete A due to his squatting program. Squatting has a intense eccentric component to it (lengthening of muscles under a load), and its ability to increase work capacity is common sense with the CNS innervation and musculoskeletal activity involved.
So, athlete A may have an advantage against most other cornerbacks and linebackers, but athlete B with their ability to produce more force, can move a sub-maximal load much quicker and more efficiently than athlete A. A well rounded strength and conditioning program trains multiple aspects across multiple spectrums. The coach has the responsibility of prescribing the right type of work; ranging from how long, to how much, to how fast.
Now this was in regards to sprinting. Acceleration of our body mass is something that goes into all aspect of sport. Besides corn hole and professional hot dog eaters, the benefits of training power are immensely important to your well being. Overlooking them or not incorporating them into your current program is sacrificing performance in the long term. Training this full body effect is Necessary if you want to produce a highly resilient and prosperous athlete. Whether your sport is sprinting based or life based, some type of power training can go a long way!
Irwin, Gareth & Kerwin, David & Rosenblatt, Ben & Wiltshire, Huw. (2007). EVALUATION OF THE POWER CLEAN AS A SPRINT SPECIFIC EXERCISE.