purchasing EMS units

[Pmoax19]

@gciriani

In a nutshell, frequency relates to fiber type, in terms of slow-twitch (type 1), fast-twitch (type 2a or intermediate), fast-twitch (type 2b). Pulse-width duration relates to chronaxie, i.e. the ideal pulse-width to contract a particular muscle group, with the maximum effect and the best comfort; i.e. upper legs muscles will have a different chronaxie compared to arms; muscle size and athlete size will also influence this parameter, the larger the muscle, the longer the chronaxie and the pulse width.

Frequency:[ul]
[li]1-15 Hz massage and recovery;
[/li][li]15-20 Hz still massage for higher level athletes, endurance for amateurs, slow-twitch fibers type 1;
[/li][li]20-50 Hz, Endurance (sport events longer than 30 min) for higher level athletes, slow-twitch fibers type 1;
[/li][li]50-75 Hz, Resistance (sport event less than 30 min, fatigue resistance required), fast-twitch fibers 2a (aka intermediate);
[/li][li]75-100 Hz, Maximum Force (sport event less than 30 min), fatigue resistance required, fast-twitch fibers 2a (aka intermediate);
[/li][li]100-120 Hz, Explosive strength, sport event duration of few seconds, no fatigue resistance required, fast-twitch fibers 2b.
[/li][/ul]See this link, for a definition of the different types of fibers and how they relate to length of sport event.

The Globus Premium Sport used to have a program called Reactivity at 125 Hz, used for sport events like jumps (basketball, volleyball etc.), throws etc. but it has been since relabeled as the highest level explosive strength.

The problem with using the wrong frequency is that if done religiously day after day, it will convert some fibers of one type into fibers of the other type. I found details of this conversion, in this excellent electrostimulation-science, college-level book: G. Vrbová, O. Hudlicka, K. Schaefer Centofanti Application of Muscle/Nerve Stimulation in Health and Disease, Springer 2008.

So if you train for a marathon, you probably want to use frequencies below 50 Hz, lest you convert some of your fatigue resistant fibers into less fatigue resistant fibers.
Giovanni Ciriani

These questions are to any and all.

I have a question regarding the frequency. If you were working at a frequency of 75Hz could you extend the period beyond 10 seconds. Couldn’t you extend the period to around 40-50 seconds? The only reserve I have about this is that it could be hard to maintain a high level of contraction.
Another question, I have been incorporating stim lately and the first few weeks I felt good solid contractions, but the last two sessions it has been more painful and more of a straining sensation at a lower intensity than what I have been doing. Is there a reason for this. I have been doing 10/50 at 100Hz.