The Explosive Strength Deficit - Esd
What I am going to write about today is not a general specific fitness variable e.g. Strength or Endurance. I am going to write about the ESD which is a very important aspect of training to work out for an athlete competing in high level competitions. The ESD will show the percentage of an athlete’s strength potential that was not used in a given attempt of an exercise. This I hope will enable you to work-out where you are weak and help you plan to further progress to your athletic performance.
In the progression and history of power development it is imperative you become well known to the Explosive Strength Deficit. This is an excellent tool and skill to have as a coach or an athlete. In this article I am going to show you a basic way of analyzing results, assess, and to show you a clear path in how to maximize your potential power in the playing field.
Movements above occur very quickly in many explosive sports, it is not possible to exert maximum strength because maximum strength or force takes time. Researchers have shown that in an isometric or static muscular contraction, maximal force is reached in 0.3-0.4 sec but typically it will take over 0.4 sec for the time to reach peak maximal force What does this chart tell us?
Movements are typically performed in explosive sports (Shot-put, Javelin, Hammer-throwing) the speed of contraction happens so fast that the object is released before the neurological system can produce maximal strength production
A most common way to test the E.S.D is through the use of the vertical jump test, you will need a measurement of the static jump test. This will mean to jump with bent legs holding the position for 3-4 seconds and then exploding upwards. Then you would do a dynamic test which is a vertical jump preceded by a sudden dip to activate your stretch reflexes which will help you achieve a greater force .The difference between the two should then be calculated.
The dynamic way subtract away from the static=strength deficit.. The acceptable difference is 20% if the difference is more than 20% then you are lacking explosiveness. Therefore you will need to concentrate more on explosiveness such as Olympic lifts for low reps. Plyometics and medicine ball work are effective for training the nervous system to fire quicker and produce more force.
If there is a difference of 20% the effectiveness would move towards hypertrophy (muscular size) using moderate weights with more repetitions and shorter rest periods. The main aim would be to improve your starting strength. The exercises can be basic and the focus should be on multi-jointed exercises which do stimulate a lot more muscle fibre.
Most skill-orientated sports involve ballistic movements that occur much quicker than the time it takes to reach maximum force. If you leave the time slow the more max strength will start to dominate, but on the other way around if the movements are quick, strength plays a much lesser role. RFD (Rate of Force Development) your ability to activate as many muscle fibres in the shortest amount of time becomes the main factor for success. This activation can be classed as explosion!
Hope you have enjoyed reading
Train Explosively
My name is Glenn Parker i coach and train athletes and clients in the City of London. I have taught trainers from various health clubs around the country and coached Football teams and rugby clubs in sport-specific strength training. My aim is to enable people to participate in strength training as they have a small amount of knowledge in the field of resistance training.
Tags: E.S.D, Explosive, fitness, maximum force, Maximum strength, Strength
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