During EMS training the exercising person wears a wired, tight and moist sports suit that can electrically stimulate distinctive groups of muscles. The electrical current is said to aid fast muscle development with minimum effort on the side of the training individual. 

Training sessions are made up of individual poses that are held for several seconds. One exercise, for example, has the person standing with their legs apart, knees bent and arms opened wide. It is supposed to strengthen the chest muscles. Another exercise guarantees 'firm thighs' and a 'sexy bum.'

The theory behind EMS: The electrical current is thought to intensify muscle contraction by reaching deeper muscle fibers and strengthening them. Although this method is frequently used in physiotherapy, high-performance sport and for medical purposes after operations, its application in gyms is a relatively new trend.

EMS can cause kidney damage

A trend, moreover, which experts of the German Society for Clinical Neurophysiology and Functional Imagery (DGKN) are now warning against. To date, it is unknown whether EMS training is effective, they say.

"If used incorrectly, EMS can cause muscle damage. When this occurs, small muscle particles are released into the blood stream and can damage the kidneys," explains Professor Dr. Stefan Knecht, DGKN spokesperson and chief physician at the clinic for neurology at St. Mauritius therapy clinic in Meerbusch, Germany.

This muscle damage is caused when high-intensity training increases levels of creatine kinase (CK), an enzyme which normally supplies the muscles with energy. People suffering from pain, palpitations or weakness after EMS training should see a doctor immediately, the DGKN advises.

Medical supervision is necessary

Whereas physiotherapists and doctors are specifically trained to oversee EMS training sessions, most gym employees lack the correct education or knowledge to do so. A failure to properly assess the maximum electrical exposure can cause severe damage to the muscles and kidneys. Although EMS training sessions are brief, they are quite intense — making it important to drink plenty of water after sessions.

"In moderation and under medical supervision, EMS training is acceptable. Before starting, you should definitely have your liver function checked and make sure that you are not suffering from a muscle disorder," informs Knecht. Without medical control, one should also refrain from combining EMS and high-intensity training.

While neurophysiologists at the DGKN advise against EMS training, they do suggest sticking to a regular fitness program.