We know approximately the results which we can obtain with standard sports training. If we decide to run in a popular race, we know that there is a generic period in which we will do most of the work, focusing on the more pure aerobic resistance. In the specific period we will dedicate some more time in strength training if we want to improve results. The exact same thing occurs when we want to do physical preparation for any type of sport or competition using electro-stimulation. This can be done without any type of difficulty so long as we understand that we have to work with a range of frequencies that allow us to generate the precise stimulus to work the muscle as much and as efficiently as desired.
As with series or fartlek training, which imply a change in the frequency and the type of daily training, when using an electro-stimulator we can also use different ranges of frequencies which each produce a different effect. As we will see, the body adapts physiologically to electro-stimulation as much as to classical training, whether it be for strength, resistance or speed, or a combination of the various factors previously mentioned. The similarity between one type of training and another is at its maximum if the electro-stimulator equipment which we use meets the highest quality conditions and comes close to the optimal physical stimulus for each type of training.
The selected frequency mode is the key for telling the body which type of muscle fibre to activate. To put it another way; the selected frequency mode will stimulate the desired type of muscle fibre, depending on the training phase in which we find ourselves. As briefly mentioned earlier, a high frequency with an adequate amplitude allows us to develop strength and anaerobic resistance; low frequencies allow us the relax the musculature or improve our aerobic resistance. The effects of the frequency setting are as follows:
1. Between 2 and 4 Hz we will cause a relaxing effect of the muscle or group of muscles on which we’re working, even if we have overloaded the area and pain has appeared when training previously. In many cases we can observe the pain cease to be a problem or disappear completely. We are not producing an anaesthetic affect on the zone but improving the trophism, increasing circulation and pulling out waste substances. Furthermore, with a frequency of 4 Hz we hit the threshold at which enkephalins are produced, which will elevate our pain threshold, so as it ceases to be a problem. At the same time, we break the cycle of pain producing spasms and spasms producing more pain, and so on.
2.- Between 4 and 8 Hz we obtain a notable elevation in the secretion of endorphins. At the same time, we raise the intensity until we clearly notice the contraction and, upon correctly placing the electrodes, we obtain a massage affect on the muscle group on which we’re working, which elevates the pain threshold. At the same time, we notice positive affects which generally are the result of a local massage, such as intense sensation of relaxation on the zone, improvement of local circulation, decrease in metabolic toxins and improvement in oxygenation.
3.-Between 8 and 12 Hz we achieve a big increase in the local circulation, with all that goes along with it: increase in trophism, decrease in the number of metabolites, oxygenation of tissues, and a certain massage affect, adjusting the parameters so as a nice sensation is experienced.
4.-Between 12 and 40 Hz we essentially activate just the slow fibres. To give an example, it would be the equivalent to doing muscular work for running; we continue slowly so as to improve our aerobic capacity whilst training with barely any oxygen deficit.
5.-Between 40 and 60 Hz, depending on the amplitude, we cut out more slow, medium and quick fibres. With this training we will achieve a better load level than with the lower setting, as well as better muscular resistance, and we would also begin to strength train, improving the level of oxygenation at the same time.
6.-Between 60 and 80 Hz, depending on the amplitude, incorporated into the work are intermediate and quick muscular fibres, and we find ourselves really working on strength and developing musculature.
7.-Between 80 and 120 Hz the quick fibres will be working with great intensity and with this we will improve strength, speed and the combination of both: resulting in an increase in muscle power; and all without a sensation of psychological or mental exhaustion.
NEUROMUSCULAR TRAINING; INTENSITY, FREQUENCY AND RECRUITMENT OF MUSCLES.
The effectiveness of training with electro-stimulation is related very clearly with two parameters; spacial recruitment and temporal recruitment.