Methods of carrying out repetitions

For strength workouts, repetitions of movements within the set can be implemented in different ways. Each of these ways has its own specific purpose and is crucial to the success of the strength workout. It is not enough to identify which exercise, how many repetitions and sets need to be done and the duration of breaks. The method for carrying out the repetitions must also be defined.
There are several approaches to performing repetitions:
- Fluent concentric
- Fast concentric
- Explosive concentric
- Eccentric
- Isometric
- Eccentric-concentric
Fluent concentric
The fluent concentric implementation is intended to increase muscle mass and improve physical endurance. In regard to safety, fluid concentric repetitions are the most useful for workouts to improve health and well-being. The basic objective is to connect individual repetitions without an intermediate break and rest. For example, lifting weight (concentric work) lasts approximately 1 second, and lowering weight (eccentric work) 2 seconds. The transition between lowering and lifting of the weight is fluent without thrusts. Without rest means that muscles work non-stop to complete the set with high, and ideally even, relative intensity. Rest means that the weight rests on the base, that you completely outstretch your arms or legs so that the load is transmitted almost entirely on the skeleton, and the weight has no lever to cause torque. Amplitudes of movements for the same muscle can be different through the use of different equipment. When bending the elbow in a training device with 'a kidney', it is possible to implement the movement almost through the entire range of amplitude. When bending with a lever, amplitude will be significantly smaller, because you will have to stop bending the elbow long before the forearm reaches vertical position. The lever of the handle will reduce movement too much and the load on the muscle will be too small, which in effect means it will rest. Squats with the bar are not implemented to completely extend legs, but with much less extension, until the muscles still work with high intensity. Usually, we exhale during the concentric part and inhale during the eccentric part of the repetition.
Fast concentric
Fast concentric implementation of repetitions is intended for transition from fluent to explosive concentric implementation. It is similar to fluent concentric except that the concentric part is implemented faster, with a speed objective of 60-80% of maximum explosiveness. Emphasis is on the exhale at the beginning of the concentric part.
Explosive concentric
Explosive concentric implementation is typically used for the improvement of muscle activation. Every repetition is implemented independently from the others. Weight in the initial position rests on a stand, so it is not necessary to hold it. When the weight is set, a carefully set procedure follows. Position under the weight in preparation for lifting. After deep inhalation, contact with the load is made (for example, tighten wire rope, slightly press against the bar, etc.) followed by concentration on the lift and, once we are prepared, explosion. Explosion means that we are trying to lift the load in an extremely short time with extremely high speed. Explosion is connected with a forceful exhale. Movement is implemented with maximum amplitude (pushing to the end). Returning to the initial position is not essential, since the emphasis is on safety for the athlete and the equipment. After returning the load back to its initial position, we let it go, quickly shake active muscles, breathe and repeat the procedure with the next repetition. Usually, the break between repetitions is approximately 5 seconds. There is an increased risk of injury because control of movement is reduced for the explosive concentric approach. Therefore, it is necessary to master the exercise, before beginning with explosive realization.
Eccentric
Eccentric implementation of repetitions is used for improving muscle activation. Here the main emphasis is on safety, since loads are heavier than you can lift. It is therefore necessary to provide a blockade in the lower position to safely stop the weight. The key part of these repetition is the controlled lowering of the weight in terms of maximum eccentric strain, which lasts 2 seconds. If it is less, the weight is too big and if slower, too small. Each repetition is performed separately. The weight at the beginning rests in the bottom position. Assistance is needed to raise the load. This can be accomplished with an assistant, or with help from the other side of the body, if you implement unilaterally. In the case of an assistant, good communication is required, because you must be ready to take the weight when the assistant lets go of it. If not, you cannot efficiently hold the weight.
Isometric
Isometric implementation of repetitions is used for activation, increased muscle mass and muscle endurance. The key is to maintain a certain level of force in a given situation. In activation workout, force is increased as high as possible, and you must hold this maximum force for a few seconds. Otherwise, the procedure is the same as in explosive concentric exercise, with the exception that there is no movement. In terms of muscle mass and muscle endurance, the increment of force is slower, with the predicted force achieved in approximately 2 seconds.
Eccentric-concentric
Eccentric-concentric implementation of repetitions is designed to improve muscle activation and the ability to exploit elastic characteristics of muscles and tendons. Tissue load is the highest and therefore the risk of injury in concentric-eccentric load is the greatest. Eccentric-concentric requires good advance preparation and excellent technique. Maximum load during the transition from the eccentric to concentric part occurs in the lower position, or so-called 'switch'. It is therefore necessary to ensure protection when in the bottom position. Repetition starts at the top position. This is followed by lowering the load, quick stopping of the load and immediate transition to an explosive lift of the load. You inhale before descending with weights. During lowering, hold breath and during lifting, either exhale with force or continue to hold it. Repetitions can be performed individually or connected in a series.
There are two versions of eccentric-concentric repetitions. Described above is the so-called implementation with the opposite movement. Reflex potentiation is not a part of it (but reflex inhibition may occur), and forces are slightly lower than in the jump type implementation, which includes depth jumps. The main difference is that with the jump type, impact and sudden stretching of muscles occur, triggering a reflex potentiation, since there is no blow from an opposite movement. The objective for the jump type version is to implement movement in the shortest possible time and achieve maximum speed of movement (jump height).