Why should we do power training, isn’t strength training enough?
In the world of sports, power training and strength training are either used interchangeably or the difference is seldom understood. Both forms of training have their place in a well-designed training program.
What is power?
If you are anything like me and never really understood Physics in school, I will make it as simple as possible here.
In Physics Power is the rate of doing work and can be equated as Power equals work divided by time.
In the previous article The Fundamentals of Strength Training (link to previous article The Fundamentals of Strength Training). I explained how work can be defined as the product of force and distance, therefore Power is force multiplied by distance divided by time.
Power = Force * distance / time
Power = Force * velocity
Because the formula for velocity is velocity equals distance divided by time. If all this is over your head, have a look at the picture and it becomes clear.
What is power training?
The bottom-line from the physical derivation from above is, that power has two variables force and velocity that we can address in our training. If you are interested in practical examples, the slideshare below has a few good examples from slide 63 and following slides.
In other words, power is the ability to exert the highest amount of force in the shortest period of time. In most sports, you rarely have much time to apply force, the challenge is to apply as much force as possible within a limited time frame.
An example of a typical Power Training could look like this
What Does Power Training Improve
Wondering if power training is necessary or strength training is enough. What are the areas that power training actually help to improve? We are aware that power is the ability to produce force in the shortest period. Let us look at a practical application of it in sports.
High level 100 meter sprinters have ground contact times (the time, the foot is in contact with the ground) of less than 80 ms (milliseconds). The better the sprinters the lower the ground contact times. This means, the athlete has 80 ms to apply force that propels the athlete forward.
In sports like Volleyball and Basketball the ground contact time of a jump can be as low as 170 ms up to 300 – 400 ms depending on the type of jump.
In throwing sports the time to apply force onto the object that is thrown, whether it’s a baseball, a handball or a cricket ball is between 150 – 180 ms. The same applies for hitting sports (tennis, baseball, hockey and many more), the time to exert force onto the racket, bat, stick or whatever implement the sport requires is between 180-250 ms.
The vaulting actions in the various gymnastic disciplines the hands are in contact with the ground or implement for 180-210 ms.
The force application of kicking a ball in soccer or football ranges from 120-160 ms and results in 10 ms contact with the ball.
However all these numbers illustrate the need to apply force quickly within a given time frame and this is what power training is all about. Applying the highest amount of force in the shortest period of time.
What training mode is most effective for power training?
Power can be trained with different training modes, whether it is bodyweight or external resistance such as barbells, dumbbells, kettle bells, medicine balls or resistance bands. There are different modes of power training like body weight or external resistance such as dumbbell or kettle bell medicine balls. The training mode is in most cases dependent on zone of the force velocity curve we want to train.
What are power training efforts?
We do not only have different modes of power training, we also have different efforts of power training. Since power is the product of force and velocity, it implies that the effort is always a maximal voluntary effort. We can distinguish this maximal voluntary effort into three efforts:
- Ballistic effort
- Dynamic effort
- Plyometric effort
A ballistic effort is, when at the end of the activity or movement, the object is propelled into a free flight. For instance, upon jumping, the body goes into a free flight at the end of the movement or force application. Similarly, a thrown medicine ball is going into a free flight.
A dynamic effort is, when we the concentric movement is executed with the highest possible velocity. An example could be in a bench press, where the bar is lowered to the chest in a controlled manner and pressed up as explosive as possible. The Westside Barbell has adopted that concept for their dynamic effort days.
A plyometric effort is, when the body makes use of the so called stretch-shortening cycle where the muscle is rapidly stretched in the eccentric phase, followed by a rapid shortening of the muscle in the concentric phase. The rapid shortening elicits the stretch reflex or myotatic reflex a protective reflex of the body, which results in a stronger muscle contraction.
What are the right power training intensities?
Power can be trained across a wide variety of intensity zones, ranging from 80-85% of the 1RM (RM = repetition maximum, the weight, that can be lifted for one repetition) to 0% 1RM. In the sporting practice, the training zones range from 50-70% of the 1RM, 20-50% of the 1RM and 0-20% of the 1RM. These ranges are rather flowing and not fixed however they serve as a good guideline when designing power training programs and power training workouts.
Putting the information together.
For intensities of
– 50-70% 1RM we use the dynamic effort
– 20-50% we use the ballistic effort
– 0-20% we use the plyometric effort
What about energy systems and power training?
When we are utilizing power and training power, we are making use of phosphagen system. The phosphagen system provides us with the highest amounts of energy for short period of time (6 to 10 seconds)? This means if you want to do an effective power training or power training workout, your efforts have to be completed within 6 to 10 seconds. The question is now how many times can you repeat a movement within the period of 6 to 10 seconds (better 6 seconds). The answer depends on the ROM (range of movement) of the exercise. The phosphagen system provides high amounts of energy, exhaust quickly and needs a long time to replenish (3-5 minutes), therefore the rest between training sets should take this information into consideration.
For more detailled information on energy systems and how the energy system influences Power Training and Power Training Methods have a look at the article
What does Power Training Do?
What does power training actually do? To grasp that, an understanding of muscular activation is necessary. Three different mechanism come into play to activate a motor unit, a nerve that controls the related muscle fibers, recruitment of muscle fibers, the firing frequency and the synchronization. Recruitment of muscle fibers means the number of motor units that can be activated at a time. The firing frequency is the speed at which these motor units are activated and the synchronization is the coordinated effort of motor units to work together.
In producing force, the recruitment of the maximum number of motor units is most important. When it comes to power, the speed at which the motor units are activated is important. In other words, the firing frequency plays a key role.
In the practical application of designing power training programs, we begin with a period of strength development and then maximum strength, in order to maximize the recruitment of motor units, before we start implementing power training workouts.
Power Training Conclusion
If you are participating in a sport where you have a limited time to execute a skill or movement, you should consider to implement power training into your training program.
Depending on your sport and the requirements of your sport, you chose the appropriate training intensities with the adequate training efforts.
Make sure you follow the correct order in planning process, strength development training before maximum strength training and maximum strength training before power training.
More information on Power Training
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