What is Reactive Strength Performance?
>> July 26, 2015
Ability to change quickly from eccentric to concentric is one quality that can distinguish between the better and the best athletes. This is called as reactive strength. Because eccentric is basically "lengthening" action and concentric is "shortening," reactive strength, therefore, represents the ability to utilize stretch-shortening cycle, or plyometrics.
Dietmar Schmidtbleicher once told me that definition of strength qualities are not invariably consistent, despite "a consensus has been reached" during several conference meetings with his American and European colleagues such as William Kraemer, Steven Fleck, and Keijo Hakkinen. Despite the different terms being used to describe muscle actions, they are intended for the same matter, and fundamentally similar when it comes to actual "practical".
The reactive strength performance considers two components;
A higher force generation during a contact phase may increase the ground contact time. As a penultimate (last) contact can create a larger "braking action," such as the long jump take-off (~0.15s), it can as well promote a larger impulse and therefore a higher forward force propulsion to launch the body forward.
However, it may not a constituent for other sports contexts as having longer contact phase means the occurrence of excessive (not optimal; too long) braking action also takes place apart from a reduction in the velocity. Hence, an optimal and fast (~0.08s in maximal-sprint; ~0.15s long jump take-off) contact time with a higher force generation can promote a better performance. Again, this is a reactive strength quality (and also explosive strength).
Reactive strength is different from explosive strength
It can be confusing if one wishes to distinguish between the two as both have similar characteristics, and even occurs almost concurrently. Take a look at different definitions and examples.
Definition 1
Example 1 - different exercise
Example 2 - same exercise
Dietmar Schmidtbleicher once told me that definition of strength qualities are not invariably consistent, despite "a consensus has been reached" during several conference meetings with his American and European colleagues such as William Kraemer, Steven Fleck, and Keijo Hakkinen. Despite the different terms being used to describe muscle actions, they are intended for the same matter, and fundamentally similar when it comes to actual "practical".
The reactive strength performance considers two components;
- Time (duration)
- Displacement (effort)
A higher force generation during a contact phase may increase the ground contact time. As a penultimate (last) contact can create a larger "braking action," such as the long jump take-off (~0.15s), it can as well promote a larger impulse and therefore a higher forward force propulsion to launch the body forward.
However, it may not a constituent for other sports contexts as having longer contact phase means the occurrence of excessive (not optimal; too long) braking action also takes place apart from a reduction in the velocity. Hence, an optimal and fast (~0.08s in maximal-sprint; ~0.15s long jump take-off) contact time with a higher force generation can promote a better performance. Again, this is a reactive strength quality (and also explosive strength).
Reactive strength is different from explosive strength
It can be confusing if one wishes to distinguish between the two as both have similar characteristics, and even occurs almost concurrently. Take a look at different definitions and examples.
Definition 1
- Reactive strength - ability to produce a high amount of force in a minimal time.
- Explosive strength - ability to produce a high amount of force in a minimal time.
Definition 2
- Reactive strength - ability to effectively utilize the stretch-shortening cycle in a minimal time upon impact on the ground.
- Explosive strength - ability to generate a higher rise in force production in a minimal time, once a movement has started.
Example 1 - different exercise
- Reactive strength - multiple hurdle jump
- Explosive strength - box jump (onto a box)
- Reactive strength - landing phase of the drop countermovement jump
- Explosive strength - extension phase of the drop countermovement jump
Example 3 - long jump
- Reactive strength - the take-off action, a fast stretch shortening cycle
- Explosive strength - the rapid flexions and extensions of muscles involved
Reactive strength is also linked to Rate of Force Development (RFD), which has been explained earlier.