EMS means “electrical muscle stimulation”, EMA means “electrical muscle activation”. Basically, in both cases, the aim is to trigger muscle contractions through electrical impulses. If this is produced with so-called stimulation current (low-frequency current), then it is traditionally referred to as EMS. The motor nerves are irritated, this eventually leads to muscle contraction.
If the modulated medium frequency current is generated, one prefers to speak of EMA. In this case, the muscle contraction is triggered directly in the muscle cells without irritating the nerves. This provides a more pleasant perception of the pulse during training.
The effectiveness and mode of action of EMS training has already been proven in several studies by different universities. Among them we count the Sports University Cologne, University of Bayreuth as well as the University of Erlangen-Nuremberg.