The intensity of an electric current is the flow of current passing through a circuit. It is measured in Amperes, but for electrostimulation, milliAmperes are used. Today, Compex stimulators display an intensity value that doesn’t correspond directly to milliAmperes. This scale ranges from 0 to 999 (depending on the model).
What Is the Purpose of Intensity in Electrostimulation?
For muscle-targeted electrostimulation, intensity alone determines how many muscle fibres are activated. Muscle fibre recruitment happens from the surface inward. Very low intensities only activate the most superficial fibres and are of limited use. Higher intensities engage a greater percentage of muscle fibres.
Three Stimulation Modes with Different Goals
There are two types of neuromuscular electrostimulation programs and one type of program for pain relief:
1. Development Programs – Muscle Contractions
These aim to improve muscle qualities such as endurance, strength, or speed.
- The program begins with a warm-up and ends with relaxation.
- The work phase alternates contractions and active rest.
- These programs are akin to real strength training sessions.
2. Massage and Recovery Programs – Muscle Twitches
They work indirectly by activating blood flow, providing pain relief, and relaxing muscles, e.g., active recovery or capillarisation.
- They do not produce direct muscle gain.
- Stimulation is continuous (no contraction-rest alternation).
- These programs are closer to various forms of massage.
3. Pain Relief Programs – Tingling Sensation
TENS programs mainly relieve pain by modulating pain signals sent from nerves to the brain. They can be used for chronic, acute, or post-operative pain. Electrodes are usually placed near the painful area or along nerve pathways. These do not target muscle strengthening or stimulation.
How to Adjust Intensity for Each Mode
Muscle twitch programs
For these, aim for a muscle response resembling a beat or strong vibration—called muscle twitches. This activity differs from a true contraction and acts like a pump to significantly increase blood flow to the stimulated muscle.
As intensity rises, muscle twitches start subtle, then grow stronger until reaching a maximum plateau. Going beyond this intensity gives no extra benefit.
For devices with Mi-Range technology, the optimal stimulation zone appears on the screen.
Pain relief programs
For TENS, epicondylitis, and tendinitis programs, increase intensity gradually until you feel a pleasant tingling.
These programs effectively treat pain based on the Gate Control principle. There should never be a contraction.
Development programs
Intensity is the key to success here!
These are WORK programs where potential gains result from the work done. Since intensity controls how many muscle fibres are engaged, the absolute rule is to always try working at the highest tolerable intensity whilst maintaining good form. Scientific studies agree: progress is proportional to the intensity used in sessions.
Sessions require minimum effort and some grit—it’s not always pleasant, but definitely doable.
How to Progress Intensity in Development Programs
It’s normal not to reach high intensities from the first session! The first session helps familiarise yourself with involuntary contractions and the rhythm of stimulation. Most people quickly get used to it, and what initially feels intense becomes comfortable after a few sessions.
You should always aim to increase intensity by:
Gradually raising intensity every 3-5 contractions during a session (a beep reminds you if you forget).
Between sessions, note your final intensity and aim to exceed it next time (e.g., from 186 last session to 200 today). The free Compex Coach app helps track this.
Conclusion
Intensity is a crucial factor for meaningful results. For complementary programs, intensity should produce strong muscle beats. Development sessions should use the highest tolerable intensity whilst maintaining good form, progressing throughout your training.
Intensity fundamentally controls electrostimulation effectiveness. On a stimulated muscle, the number of fibres engaged depends on the stimulation intensity.
Compex’s exclusive MI technology helps evaluate physiological parameters and automatically adjusts stimulation settings, including intensity in some programs.
FAQ
❓Is it normal not to tolerate high intensity at first?
Yes. The first session is for adapting to involuntary contractions. Over time, what feels intense becomes comfortable, allowing gradual intensity increase.
❓Should I always feel muscle contraction?
Depends on the program:
Yes for muscle strengthening (force, endurance, explosiveness).
No for recovery, capillarisation, or pain relief (TENS), where stimulation should stay gentle without visible contraction.
❓Can I get injured from too high intensity?
No. Electrostimulation is safe with defined protocols. Pain or discomfort indicates your limit. Never exceed your comfort level. You might experience muscle soreness afterward.
❓How do I know if my intensity is enough?
Muscle programs: strong, regular, localised contractions.
Massage/recovery: visible muscle vibration or twitch.
TENS: mild tingling without discomfort.
❓Are intensities the same for all muscles?
No. Each muscle group has different sensitivity. For example, quadriceps often need higher intensity than biceps. Always adjust intensity to the target area.
❓What is the max intensity on a Compex?
Ranges from 0 to 999 .This scale is proprietary and doesn’t correspond directly to milliAmperes. Personal tolerance sets your limit.
❓Is there an app to track intensities?
Yes! The Compex Coach app helps plan sessions, log intensities, track progress, and reach your performance goals.
