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Muscle Stimulator To Improve Your Training

Compex SP 4.0

Improves your performance and helps you recover faster.

Including all the features of SP 2.0, SP 4.0 also offers rehabilitation programs that can be helpful for athletes with frequent injuries who practice their activity 3 times per week.

Compare this to our other muscle stimulators, learn more about training using a Compex device as well as bespoke training plans, and find out more about what muscle stimulation is.

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This product is covered by our Compex 2 year warranty. Register your product here to receive 1 extra year.



Equipped with unique MI (muscle intelligence) technology, Compex stimulators adapt to each of your muscles to provide the most effective muscle stimulation possible, while offering greater comfort and better performance

Boost your performance*

Boost your Performance

*Learn more about our scientific studies.



scans the muscle and automatically adjusts stimulator parameters to your physiology.


makes it easier to adjust stimulation levels for anti-pain programs to ensure optimal results.


indicates the optimal level of stimulation to use for Recovery and Massage programs.


Categories and programmes


Endurance, Resistance, Strength, Explosive strength, Cross training, Core stabilisation, Hypertrophy, Muscle building, Warm-up, Capillarisation


Training recovery, Competition recovery, Relaxing massage, Reduce muscle soreness, Reviving massage

Pain management

Pain management TENS, Reduce muscle tension, Muscle pain, Neck pain, Back pain, Tendinitis, Heavy legs, Cramp prevention


Muscle atrophy, Reinforcement


Firm your arms, Tone your thighs, Get a 6-pack, Firm your stomach, Shape your buttocks



See what our users think of us

Product Questions

Question by: Adam Appleton on 12 Feb 2020 12:13
No. There is no danger if the electrodes are badly positioned. The stimulation will simply become less effective.
Answer by: Adam Appleton on 12 Feb 2020 12:14
Question by: Adam Appleton on 12 Feb 2020 11:33
Compex muscle stim uses very high quality and high comfort level currents.
Muscle stim can be used in an intense way in complete safety:

- Without causing nervous fatigue
- By protecting your joints
- Electrostimulation has no side effects; it is a non-invasive treatment method, often an effective alternative to drugs, for pain treatment.
Answer by: Adam Appleton on 12 Feb 2020 11:41
Question by: Adam Appleton on 12 Feb 2020 12:10
Yes. The work carried out during Compex sessions (depending on the programme selected) induces adaptations in the muscle fibres, with one of them being the increase in muscle volume.
Answer by: Adam Appleton on 12 Feb 2020 12:11
Question by: Adam Appleton on 12 Feb 2020 12:06
Muscle Stimulation is a tried and tested medical treatment method, used for rehabilitation, pain treatment and for training sportsmen and women.

The working principle behind muscle stim is very simple. It faithfully reproduces the process by which muscle contractions are controlled by the brain.

So, with muscle stim, the activity in your muscles is triggered by electrical impulses sent by our devices to the motor nerve. Your muscle cannot distinguish between a contraction triggered by your brain and one triggered by muscle stimulation. This is known as electrically induced contraction.
Answer by: Adam Appleton on 12 Feb 2020 12:09
Question by: Adam Appleton on 12 Feb 2020 12:17
Where to place the electrodes is indicated in the Compex manuals for the different muscle groups.
Answer by: Adam Appleton on 12 Feb 2020 12:18
  • Stimulator
  • Set of 4 Snap wires
  • MI-Sensor wire
  • Charger
  • 4 Snap electrodes 5x10 cm
  • 8 Snap electrodes 5x5 cm
  • Transport case
  • Instruction manual
Technology: Wire
Muscle intelligence: MI-scan, MI-range, MI-tens
Web connection: No
Download objective: No
Upload remote history: No
Program categories: Conditioning, Fitness, Pain management, Recovery / Massage, Rehabilitation
NB of programs: 30
NB of channels: 4
Screen Matrix monochrome
Power: 120 mA, 400 us, 150 Hz
Energy: Rechargeable battery in less than 4h30

Instructions for Use

  • Quick start guide
  • IFU
  • How to use (FAQ)

    Body position during stimulation

    This position varies according to the muscle group that you wish to stimulate and the programme that you are using.

    For programmes inducing powerful muscular contractions (tetanic contractions), it is recommended to stimulate the muscle isometrically. You should therefore hold the extremities of limbs being stimulated.  This position opposes maximum resistance to movement and avoids any shortening of the muscle during contraction, which would risk causing cramps. For example, when stimulating the quadriceps, you should be in a sitting position with ankles held to avoid extending the knees.

    For the other types of programmes which do not induce powerful muscular contractions but only muscular twitches or tingling, position yourself as shown on the illustration, maintaining a comfortable position.

    Adjusting stimulation intensities

    On a stimulated muscle, the number of fibres used depends on the stimulation intensity.
    For programmes inducing powerful muscular contractions (tetanic contractions), you must use the maximum stimulation intensities (up to 999) while remaining within your tolerance threshold, in order to
    use the maximum number of fibres. The progress of a muscle will be greater the higher number of fibres that are worked. During a session it is therefore important to try to increase the intensity every 3 to 5 contractions.
    For other types of programmes like recovery, massage, capillarisation or even muscle pain which only induce muscle twitches, you should gradually increase the stimulation intensities until clearly visible muscle twitches are obtained.
    For TENS, Epicondylitis and Tendinitis programmes, you should gradually increase the intensities until you feel a tingling sensation under the electrodes.

    Scheduling of the stimulation sessions.

    The question of the scheduling of the stimulation sessions during the week only arises in situations where at least two training sessions are to be done in the same week.

    In cases where up to six sessions a week are planned, it is recommended that the sessions be scheduled as far apart as possible. For example, anyone who does three sessions a week should do them at the rate of one session every two days (2x1 rest day and  1x2 days of rest/week). Anyone who does six sessions should do six consecutive days of stimulation with one day of rest.

    Above seven sessions a week, it is advisable to group several sessions together on the same day to leave yourself one or two complete rest days without stimulation. Anyone who does seven sessions a week should do five days of stimulation, at the rate of one session per day with one two-session day(s) (with at least a half-hour's rest between the sessions), leaving one rest day. Anyone who does ten sessions a week should preferably do five two-session days (again with at least a half-hour's rest between the sessions), leaving two rest days.

    Alternation of stimulation sessions/voluntary training

    The stimulation sessions can be done outside of or during voluntary training.

    When voluntary training and stimulation are done during the same session, it is generally recommended that the voluntary training be done first followed by the stimulation. This means that the voluntary training is not done on muscle fibres which are already tired. This is particularly important for strength and explosive strength training.

    However, in resistance training, it can be very useful to proceed in the reverse order. Before the voluntary training, by means of stimulation for resistance, a “specific pre-fatigue session” is carried out on the muscle fibres without general and cardio-vascular fatigue. In this way, the voluntary effort on the “prepared” fibres will push the glycolytic metabolism faster and further.

    Progression of stimulation cycles

    The stimulation cycles are for people who are already accustomed to electrostimulation and want to perform several training cycles.

    The cycle logic refers to the workload performed by electrostimulation. Just like a normal workout, one has to to start with an amount of effort then increase it over the course of the cycles. Thus, it is recommended starting with the 1st cycle and going on to the next level when the cycle is finished, normally after 4 to 6 weeks of stimulation based on 3 sessions per week.

    It is also important to have reached significant stimulation intensities in sessions before going on to another cycle. At the end of a cycle you can either start a new cycle or do maintenance training based on one session per week.

    Instructional Video