Strength is the ability to voluntarily produce force. This means that strength is needed for every movement on the field and in the gym. However, this strength can be demonstrated in a multitude of ways depending on factors such as speed of movement, time of muscular contraction, and direction of movement. All of these factors determine the specific type of strength output that an athlete needs for a specific event. Special-Strengths are the different ways that athletes can produce force depending on the previously mentioned factors.
Principal Of Dynamic Correspondence (Yuri Verkoshansky)
In order to fully understand what Special-Strengths are, we first must understand the Principle of Dynamic Correspondence. This is a specific criteria which determines if an exercise is truly functional to the movement you are trying to get better at. The less a movement satisfies this Principle, the less it will translate and develop the qualities you are looking for, and the less it will develop the specific special-strength quality you are looking for.
Amplitude and Direction of Movement- This criteria refers to how joint and body part segments are in position relative to one another during a specific event. For example, a rowing motion and a shot put motion are not directly correlated to one another because, although they both involve movement at the shoulder, they are in opposing directions to one another. Practically, implements must be chosen that challenge force outputs in the correct plane of motion in order to translate into a specific skill. For example, sprinting with a weight vest on and running with a sled for resistance will challenge two different forms of performance. Running with a resistance sled challenges the muscles that produce horizontal motion because that is the direction that the resistance is acting on the athlete. Therefore, it will challenge the posterior chain muscles of the calves, hamstrings, and glutes more to produce acceleration force. Because of gravity, wearing a weight vest adds vertical forces on an athlete, and challenges the postural muscles of the back core and legs in the vertical plane. This may translate more to top speeds and endurance running, but will lose effectiveness if you are trying to build acceleration ability, where there is more horizontal force as mentioned earlier. It is often said by coaches that “power is plane specific”, and this criteria is what they are referring too. Just because someone is fast does not guarantee that they are a good jumper, or just because an athlete can throw a baseball 90 miles an hour does not mean they have a good 40 yard dash time. When talking about functionality, make sure the exercise chosen matches the direction of the skill you are trying to improve.
Accentuation of Force Production- The amount of force being displayed in a given movement will be different throughout the movement. In other words, there will always be a specific point during the display of a skill where force production is the highest, and this is determined by the skill, technique displayed in the skill, and leverages of the athlete.
Rate and Time of Max Force Development- The rate of force production for an exercise must match the sporting movement that one is trying to develop. Since most sporting movements do not last long enough for maximum muscular force to be developed, rate of force production becomes increasingly more important to be specific to a skill. This is a reason why heavy lifting, while does provide a great base for power development in athletics and does increase power output in most untrained individuals, is not directly correlated to power output in highly trained or advanced individuals. The rate of force development for a heavy squat and a vertical jump are not the same even though multiple other criteria for this principle is met by these two activities.
Regime of Work- The regime of muscular work refers to the type of muscular contraction being done in a sporting movement. There are eccentric, concentric, and isometric muscular actions and these can all be done in a variety of ways. This criteria also refers to the repetitiveness of the effort. Muscular work can be done as one sustained contraction, multiple contractions in succession of one another, or as a singular power contraction of maximum force just as a couple examples.
Dynamics of Effort- The intensity of work being done in an exercise must match the intensity of the skill that one is trying to develop, and the specific type of special-strength being displayed must also be matched by the exercise. Force = mass x acceleration, so not only does the force being exerted in a skill need to match for an exercise to be functional, how you get there matters too. For example, a high force might be displayed by a large mass moved at slow speeds, or a light mass moved at high speeds. Both of these require different types of special-strength levels and are displayed differently even if the amount of force may be the same.
As you can see, the criteria that determines if an exercise is truly functional or not to an activity is quite extensive. The best way to develop certain athletic skills is to practice these skills specifically. What we must look to do in the weight room is progressively meet more and more of these criteria as we get closer to an event where the athlete needs to demonstrate a specific skill. We do this by looking at the next principal.
Accumulation of Progressive Functionality (Jim Smith)
This principle states that as we progress through a macro training cycle closer to the event we want to be ready for, we must meet more and more criteria of Dynamic Correspondence in the event that the athlete will be competing in order to achieve a top performance from an athlete. General strength qualities should be focused on farther away from an event to develop your base. Most often this is done by developing an athlete's max strength since this provides a better base for all other force development. This can be done using general exercises and variations that do not look like the sport we are trying to get better at. As we get closer to a season or event, more time should be dictated to the athletes specific special-strength quality. Other characteristics of movement, like joint angles, time duration, and effort levels, can be progressed from general to specific as the athlete gets closer to season or their event.
As an athlete gets into the preseason phase of training, or a strength athlete starts meet prep, the specific type of strength they need should be worked on in order to produce the highest level of performance during the season or at the meet. These specific qualities should not be the main priority all year in order to reduce overtraining and overuse injuries, and to prevent the Law of Accommodation which states that if the same training stimulus is used over and over again the athlete will not only adapt to it but start to detrain as a result of a constant repeated stimulus. General strength and fitness qualities must be worked on during the offseason to build your athletic base. With this bigger base of fitness, your athlete will gain more from the specific training done before their season or competition.
With all of that, what are the specific special- strengths?
Maximum Strength- the max force that an athlete can produce voluntarily under isometric conditions
Strength-Speed- the ability to produce high levels of force on an object when the object is in motion and a high mass of the object is most important to performance
Speed-Strength- the ability to produce a high level of force through high levels of acceleration during an unloaded movement or on a small external resistance
Explosive Strength- the ability to produce maximum force outputs in minimal time
Relative Strength- the amount of force produced relative to the athletes body weight
Starting-Strength- ability of muscles to generate force at the beginning of muscular contraction before external movement occurs
Acceleration-Strength- the ability to quickly achieve max force production during dynamic muscular contraction
Strength-Endurance- the ability to maintain a specific level of muscular tension for a prolonged period of time, can be static- holding a position for a prolonged period, dynamic- maintaining muscular work for a prolonged period, or explosive- ability to repeatedly produce explosive movements
Reactive Ability- ability to rapidly switch from an eccentric stretch of muscles and tendons to produce a more powerful concentric contraction. Most commonly displayed as levels of explosive strength and seen practically as plyometric actions in sport and exercise.
Reversal Strength- ability to switch from eccentric to concentric muscular work while under high load (high mass)
Not only are all of these special-strengths specific, but they also must fit the above criteria of the Principal of Dynamic Correspondence in order to be considered truly functional to specific sporting skill. One can have high levels of speed-strength in the vertical plane, but that does not guarantee high levels of speed-strength in the transverse plane for rotational power. Each sport and athlete must be assessed to determine their needs. While at high levels or for advanced trainees and athletes these special-strengths work independently of one another, there is more overlap and correlation for untrained and intermediate athletes. Max strength, and more practically strength-speed, provide a base for an athlete to develop force producing capabilities, and other special-strength capabilities. A good program will provide a base for the athlete to get the most out of these specific qualities as they progress through both their training year and their athletic career.
Author- Coach Joe Zambito