MarcPro M4 electrical muscle stimulating device review

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Nietzsche said, “That which does not kill us makes us stronger.” This is especially true in strength training. As we exercise against a resistance, muscle tissue is damaged; when the muscle tissue is repaired it becomes thicker at a cellular level. Muscle damage also causes muscle cell generation, which adds new muscle tissue and strength. These process occur after exercise is complete and lasts for up to two days.  During this process metabolic waste products and damaged cellular components are removed so muscles can perform at their optimum level. So there you have it – skeletal muscle growth basics and a quote from Nietzsche in six sentences. sounds great, right?

The problem is that the body doesn’t like to be damaged and it signals this by causing pain and soreness in the vicinity of the muscle damage until the repair is complete.  Also, while a muscle group is undergoing recovery it shouldn’t be damaged further which means, for instance, that exercise must be timed to ensure performance on race day. Historically, the only way to achieve growth was to wait for it to happen. The product in this review, The Marc Pro M4, uses electrical stimulation to improve recovery results and shorten recovery time.

The Marc Pro M4 is an electrical muscle stimulation device intended for muscle conditioning in order to facilitate muscle performance. It is a type of device known as an electrical muscle stimulation (EMS) appliance and it is for stimulating muscles. Even though continued use of this product should hasten muscle recovery and therefore diminish the pain associated with recovery, it is not a transcutaneous electrical nerve stimulation (TENS) device for pain relief. The Marc Pro generates a waveform that stimulates muscles to create a unique, strong, but completely non-fatiguing contraction. The repetitive contractions that are generated by the Marc Pro set off a cascade of physiologic events that that manufacturer refers to as the Muscle Activated Recovery Cascade, or  the acronym “MARC®.” The manufacturer describes the MARC below:

The process begins with the activation of Nitric Oxide (NO), which dilates blood vessels and leads to increased flow delivering more oxygenated blood and nutrients to the area. The lymphatic and venous systems also require and benefit from localized muscle activity. Because of this, using the Marc Pro after physical activity helps move the related waste and deoxygenated blood away from the fatigued area(s). This exchange of nourishment and waste, without stress or fatigue, accelerates the recovery of the muscle.

Physiologically, the use of the Marc Pro feels different than TENS devices I’ve used in the past. The contractions are quick and painless, like a hiccup or a sleep twitch, and don’t involve lengthy muscle contractions or cramps. The manufacturer provides the animation below to describe the difference between the Marc Pro and other devices.


before discussing the user experience any more, let’s review what the unit looks like and what comes with it.


The Marc Pro comes with the following items:

  • carrying case
  • Marc Pro M4 controller
  • 2 electrode leads
  • 24 electrodes
  • charger
  • aloe vera gel
  • instruction manual


The carrying case is well-constructed with internal dividers, a shoulder strap and a carrying handle.


The controller is 6 inches long, 4.75 inches wide, 2 inches high, and weighs 1 lb 5 oz. The top of the unit features a LCD display, start/stop and set buttons for the timer, and two power/control knobs. The front of the unit has connectors for the electrical leads.



The rear of the unit has a connector for charging the controller.


The bottom of the unit contains the battery compartment. The unit contains replaceable NiMH batteries. I wonder if the unit would be substantially lighter if they marketed it with Li-Ion batteries instead. Because so many devices have Li-ion batteries these days it is important to remember that NiMH batteries are best maintained by only charging them once they are fully depleted. Maintaining batteries in this way will limit the “memory-effect” that these batteries are susceptible to.


The threaded connection for the belt clip is also observable below the battery compartment in the picture above. The belt clip is available from Marc Pro for $6.99 plus shipping. Because the control unit is rather large I would consider purchasing this or using a fanny pack to hold the controller when walking with it.

The electrical leads that connect the controller to the electrodes are 84 inches long – plenty long to reach anywhere. The electrodes are a conductive hydrogel typical of this technology and are 2 inch circles. It is important to place the electrodes back on to the plastic storage film that they come on so that the film doesn’t say “no”.  (I just try to apply them to the side that says “on”.) the ink that indicates the incorrect side (no) will actually come off with water or sweat, so make sure you keep the plastic dry.





Nothing could be simpler then using the electronics of this device. The knobs turn on and off the equipment like an electronic dimmer light switch.  The intensity ranges from 0 to 9.0 and it is very easy to fine tune the intensity to a specific value.

In comparison with other EMS or TENS units on the market there are relatively little settings on this device.  No selection of frequency or waveform is present. The only parameter adjustable by the user is the intensity.

The timer function on this unit is a little perplexing. It may be used to set a 15, 30, 45 or 60 minute countdown timer. Once the time has elapsed the device makes a couple of electronic  chirps, and that’s it. I would expect that either the alarm tones would continue until they are acknowledged or that the timer would automatically shut off the stimulation.   Fortunately, the main reason why you would use this has nothing to do with the timer and plenty of other  timing options are available.

A battery icon on the screen indicates the remaining charge level.



The manufacturer recommends that a short 10-20 minute session before activity can be a great warm-up. For the best recovery you’ll start Marc Pro shortly after workout completion or before the end of the day and use it for 30-60 minutes. For improved conditioning and performance, and to proactively address issues, use Marc Pro on the target muscles at least three times per week for at least 30 minutes per session.

I was excited to try this unit  and I’ve used it for about 5 weeks now. I have noticed that while using it that my recovery from jogs is significantly improved and that soreness from resistance training (i.e. weightlifting) is substantially reduced when I use this equipment versus when I don’t use it. I base this comparison on several workouts in which I worked left and right sides but only used the Marc Pro on one side afterward.  I alternated which side I used the Marc Pro on and tried using it on left and right sides in order to be sure my comparison is accurate. The side of my body that I used the Mark pro one had a consistently shorter and  more effective recovery then the other.  Consequently, I was prepared to exercise the recovered side more quickly than the other, which means I could, over time, exercise more frequently by using the Marc Pro then if I didn’t use it. After I was convinced of the effectiveness of this unit I continued using it on both sides of my body and noticed that I felt my recovery times were  shorter  then they had previously been.  I acknowledge that this is not a scientific study and that placebo effects and bias has not been  eliminated from consideration.  Scientific studies of this device are available here and here.

I also tried voluntarily mimicking the muscle contractions that this device creates as an alternative to using it but found I could not do it;  voluntary contractions were tiring in comparison with the non-fatiguing stimulation that the Marc Pro provides.

I do have a couple of notes regarding its usage.  First I would say that you should, for the most part, ignore the unit’s display. The intensity values are inconsistent unless electrode placement and contact is exact. Instead, focus on the way your contractions feel. You should have a good involuntary spasm but not a sensation of burning at the electrodes.  If you’re unable to achieve this at the highest setting then consider re-positioning the electrodes or using some sort of moisturizing gel to improve skin conductance.

Electrode placement makes a huge impact on the effectiveness of the device.  Significant  variation in performance  maybe achieved by re-positioning the electrode even as little as 1 inch.

In order to ensure that you are contracting the right muscle try to contract it voluntarily. if the device no longer creates contractions then you’re focused on the correct muscle.  This means that the machine works best when you’re not trying to use the muscles you’re recovering. It is best to sit or lie in a relaxed state while the device is working.


So one of the questions you might be asking yourself is, “should I spend $649 on this device?”  The manufacturer compares the cost of this unit with several cups of Starbucks coffee, but I think better considerations are medical free pain relief and the value of time. In the first case, while it is true that NSAIDs are a lot cheaper than this unit, accumulated exposure to these drugs has been shown to be harmful. (In all fairness, prolonged exposure to electrical fields has not been studied either, but there is no proof that this treatment can cause liver damage like NSAIDs can.)  In addition, this device will last for several years  so the cost of many years of pain relief drugs must be considered in a price comparison. In the end this device will still be more expensive, but doesn’t your body deserve the best treatment available?

The other consideration is the value of time. While some of the benefits that this device provides can be achieved by foam rolling, massage, and stretching, these activities cost money too, and your efforts must be focused intensely on them at the moment they are happening; you can’t really foam roll and write a WordPress post at the same time (true story).  The Marc Pro can provide muscle recovery while you relax, read a book, or watch a movie. The cost of this unit allows you to do more things in less time. If you average it out to 100 hours of use in the first year alone, the cost of this unit is less than minimum wage. Isn’t your time to do these other things worth more than $6.49/hr? If it is, than buying this is a worthy investment.

Using this device also has another profound effect: it encourages you to be more active. Because this device shortens recovery, the downtime between bouts of physical activity is reduced, which means you can be more active with less concern about paying for it the next day.

Source: The sample for this review was provided by Marc Pro. Please visit their site for more info.


Product Information

Manufacturer:Marc Pro
  • Some medical restrictions are listed in the manual -
  • shortens time for muscular recovery after exercise
  • improves the extent of muscular recovery after exercise
  • easy to use
  • may improve vascularity over time
  • expensive
  • timer has limited functionality
  • big and heavy controller

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