Introduction to Correct Muscle Stimulation through EMS
Optimizing the Frequency and Pulse Duration for Muscle Build-up and Endurance
Skeletal muscles basically consist of two types:
- White muscle fibers that contract quickly. These need a lot of energy and tire quickly.
- Red muscle fibers that contract more slowly. These are responsible for strength and endurance. Under medium strain they tire only very slowly.
Our certified stimulation current devices allow you to choose between various programs and settings. Synchronous (S) and asynchronous (A): With synchronous programs, the stimulation is carried out simultaneously on all available channels, while with asynchronous programs this happens with a time delay. This, for example, allows a particularly thorough or a particularly gentle stimulation to be achieved.
The Right Frequency for Red and White Muscles
Frequency is significant for most EMS applications and is given in Hertz (Hz). When choosing the frequency you should take into account that there are individual differences. Low frequencies (no higher than about 18 Hz) will mainly activate the slower reacting red muscle fibers. Power and endurance athletes will thus benefit from electrical muscle stimulation in this frequency range to build up muscle. When applied, it will cause a distinct contraction of the muscle.
Higher frequencies between 30 and 50 Hz stimulate the fast contracting white muscle fibers. With frequencies of over 50 Hz, the muscle is deliberately overtaxed and can thus be forced into muscle hypertrophy (muscle build-up). To avoid overtraining, the interval between the sessions must be correctly chosen so that the muscle has enough time to regenerate.
Pulse Duration for Large and Small Muscles
The pulse width or pulse duration is given in microseconds (µs). With longer pulses, the effect goes deeper and is mainly suited to larger muscles. For smaller muscles, the duration will remain below 200 µs. Some programs offer varying pulse duration to stimulate the muscle even more intensively.
Current strengths for EMS are in the milliampere range (mA). The intensity chosen depends on the user. New users and the untrained should, however, always start with lower current strengths. Following more frequent application it is up to the user to adjust the current strength slowly upwards.
Rise Time / Fall Time (Ramp)
Cold muscles should never be put under full strain even with EMS. That is why modern EMS devices ensure that muscles are gently warmed and supplied with blood by pretensioning. For the untrained, the minimum time for this is 2 seconds.
Duration of Contraction
The contraction time (ON) is chosen according to the user’s training goal. Anaerobic endurance training is achieved through numerous; relatively short (5-6 seconds) stimulations.
Maximum strength and elasticity, like pure muscle build-up, require longer contractions of 10 seconds or more.
Duration of Pauses (OFF)
For endurance training, pauses are kept short (2-3 seconds), while for maximum strength training the untrained begin with pauses that are at least twice as long as the contraction time. As training progresses, both times are adjusted to each other.
The Wave Form: Monophasic or Biphasic
Modern EMS devices operate almost exclusively with biphasic pulses, which are gentler on the skin of the user. This means every current pulse is followed by a phase with a negative counter-oscillation below the zero line.
Examples for the adjustment of the EMS parameters:
Rule of thumb for endurance training:
Low frequency: max. 15-18 Hz
Short contraction time: 4-6 seconds
Short ramp: 2-3 seconds
Short break time: 3-6 seconds
Long application time: 20-30 minutes, followed by a longer break
Small muscle: low pulse width (50 – 100 µs)
Large muscle: higher pulse width (200 – 300 µs)
Rule of thumb: muscle building & strength training:
High frequency Frequency: 35-50 Hz
Longer contraction time: over 10 seconds
Ramp time: 2-4 seconds
Break time: at least as long as the contraction time
Short application time: 3-5 minutes, several repetitions daily, similar to small muscle: low pulse width (50-100 µs)
large muscle: higher pulse width (200-300 µs)