The above-described methods have exerted such a wide influence on bodybuilding and developing muscle strength, that we called them and treated them as sets of methods under a single name. The method using an eccentric muscle action is considerably narrower in scope, although its effectiveness in the development of muscle strength is the greatest.
Interest in the influence of eccentric muscle work on the development of strength dates back to the early 1960s. It was then that extensive research started that led to the development of training methodologies that found application in sport.
The inspiration to undertake experiments with the use of “resistance in reverse movement”, because this is what this method is also called, was provided by the observations made by parachutists.
It was noted that they demonstrate very high muscle strength in lower limbs, the same or even exceeding that of the same muscles in athletes practicing jumps. Under the leadership of the then coach in athletics jumps of the USSR, Djaczkow, a series of experiments was initiated, aimed at clarifying the nature of this phenomenon. It was noted that the reason for so much strength in lower limbs in skydivers is the eccentric muscle action of the legs when in the contact between the feet with the foot-base during the jump. In order to achieve a similar effect, a series of experiments was initiated with jumps from different heights (up to 5 m), performed by high jumpers – athletes of top class. The results were indeed “staggering”, because lower limb muscle strength was growing rapidly, but the amount of jump decimated the research group, contributing to a number of injuries (especially knees).
Thus, there started observations and experiments designed to eliminate the adverse “side effects” with maintenance of strength development. The findings of further experiments were surprising and also very interesting.
It has been shown that the jump height does not need to be so great, and that the result is determined equally to load by the nature of muscle work. The jump height has been set at 70-110 cm and a detailed methodology for its implementation has been devised. Some advanced players like many-time world champion, Valery Brumel, exercised solely alternate jumps (with a barbell on the shoulders) and they proved as effective as landing jumps. This has enabled the introduction of certain generalisations regarding the theoretical and practical basis of the method.
This activity is very effective in dynamically building strength in muscles, owing to the nature of their work (with attachments moving away from each other) and the applied weight often exceeding the maximum one. Although for the execution of eccentric work there is needed much smaller number of pulses sent from the nervous system to the muscle than during concentric work, they must be much stronger, and the strength of the stimulus determines the type of motor fibres being activated. The muscle responds to such stimuli by dynamically increasing the strength, owing to the involvement in the movement of a larger number of large and powerful motor fibres with a high threshold of stimulation. Their activation is not related (as happens most often) to the speed of movement, but the value of resistance being overcome. The muscle mass gains are moderate, but strength increase, particularly that of large muscle groups, is very significant and rapidly growing.

In view of the constant elements characterising this method of building strength, it can be summarised as follows:

1. load
- maximum and over-maximum (up to 130%)
2. number of series
- low (3 to 5)
3. number of repeats
- low (2 to 3)
4. rest time
- long (from 2 to 4 min)
5. pace
- slow

The abbreviated version may be presented as follows:



Due to the heavy load on the locomotor and nervous systems, associated with the application of eccentric method, it should not be implemented at each workout. The use of loads exceeding the maximum one, and for large muscle groups, increases the time of restitution, which is also an argument for a less frequent use of this method.
Despite the fact that the development of the method and research on it concern the muscles of lower limbs, it does not mean that it cannot be used it only on them. It is useful in all sports where there is a need to develop the maximum strength, and is applied during squatting in deep knee bends, barbell lowering after the jerk, lowering on the chest when lying or standing, etc.
The lack of specificity of stimuli used in this method prevents the phenomenon of adaptation, and is one of the reasons for its effectiveness in building muscle strength.
Another reason for the rapid and significant increase in strength is the use of specially modified exercises allowing to develop high strength.



where: P - power: L - Labour: t - time

The movements serving this purpose involve immediate transition from eccentric work to concentric one e.g. landing and immediately after stopping jump-up. Changing the nature of muscle work from eccentric to concentric is a very strong and non-specific stimulus for building burst strength.
Currently, a modification of the eccentric method is often used, involving rapid changes in the nature of muscle work through the use of so-called “counter-exercises”. In these, even before the end of eccentric movement, we try to go into the opposite activity (concentric). At the time of change in the nature of muscle work, high power (P) is developed, which constitutes the essence of the exercise and results in a substantial and sudden increase in strength.
This observation was an important contributing factor in the design of a number of exercise stations – “training equipment” as well as simulators, providing objective information about many exercise parameters.
With the use of simulators (Nautilus, Mini-Gym in Poland, for example: Cybex II, Ariel) allowing the recording of physical parameters as a function of time, more and more frequently, in order to develop strength, isokinetic exercises (performed at constant kinetic conditions) are used. These may be performed in two variants – with maintaining throughout the whole movement (up and down) either constant resistance or constant speed. There are opinions that these exercises should be the main method of building strength in advanced athletes, since apart from the great potential for developing high burst and maximum strengths, they also contribute to significant reductions in body fat. Perhaps the future belongs to isokinetic exercises? We should find that out soon.