What Place Does Electrical Muscle
Stimulation Have in Strength Training?
By Philippe Sudan
The first widespread use of EMS was by
physiotherapists for injury rehabilitation and
prevention. As its effectiveness and benefits
became widely studied and recognised,
EMS was increasingly employed as a
strength training tool for athletes6.
This paper covers the use of electrical
muscle stimulation (EMS) - also known
as neuromuscular electrical stimulation
(NMES) or electromyostimulation - as a
muscle training activity.
Whereas in conventional strength training
the brain internally activates muscles with
electrical impulses in order to get them to
contract, EMS acts as an external activation
mechanism that bypasses the central
nervous system (CNS) and acts directly
on the motor neurons of the muscles. To
the muscles, it makes no difference if the
impulses come from the CNS or from an
external source.
EMS training consists of electrodes that are
placed on the skin, in direct proximity to the
muscles to be stimulated. In recent years,
they have been incorporated into body suits
that allow the simultaneous contraction of
the main muscle groups.
More specifically, this paper examines
whether EMS can successfully replace
conventional strength training methods as
far as the average person is concerned.
For the “average Joe”, EMS has never been
as popular as it is today. And this has a lot
to do with the advent of whole-body EMS
systems. Fitness studios are opening up all
over the world, offering 20-minute workout
sessions that combine whole-body EMS
with basic movements, like squats, lunges
and bicep curls. The proponents of EMS
claim that one of these sessions is the
equivalent of one to two hours of moderate
intensity gym work1.
Two hours? That’s about the usual number
of hours that Average Joe spends doing
strength training at the gym every week.
Does this mean, therefore, that EMS
training can entirely replace the
conventional strength training of the
average person?
This paper aims to answer this question
by referring to the quantitative studies that
have been conducted on the effect of EMS
training on muscle performance. It also
examines how EMS is used in practice to
train top level athletes and how the benefits
of EMS observed by professional coaches
can be applied to non-athletes.
History of EMS
Electro-stimulation has been used for
centuries, though not in the way we now
know it. More than four millennia ago in
remote Egypt they were already using fish
that generated electrical discharges for the
treatment of various pathologies2.
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Late 1780s diagram of Luigi Galvani’s experiment on
frog legs
It was the Italian physician, Luigi Galvani
who provided the first scientific evidence
that current can activate muscle when, in
1780, he discovered that the muscles of
dead frogs’ legs twitched when struck by
an electrical spark. This was one of the first
forays into the study of bioelectricity3.
During the 19th and 20th centuries,
researchers studied and documented the
exact electrical properties that generate
muscle movement. It was discovered that
the body functions induced by electrical
stimulation caused long-term changes
in the muscles. In the 60s, Soviet sports
scientists applied EMS in the training of
elite athletes, claiming 40% force gains4.
But Western countries only became aware
of its use in 1973, when Dr. Y. Kots of the
Central Institute of Physical Culture in the
former USSR presented a paper on EMS
at Concordia University in Montreal. There
he outlined the tremendous potential for
strength enhancement beyond that which
was possible by traditional (voluntary)
training methods.
His claims raised many eyebrows and
considerable effort was expended in an
attempt to validate them. Crude studies
that pitted EMS-fired muscles against
voluntarily contracted muscles (using Cybex
machines for measurement) appeared
to show that EMS wasn’t as effective as
Kots had claimed. However, the design of
these studies was flawed due to a poor
understanding of how EMS works on the
neuromuscular system5.
An EMS stimulus fires all the motor neurons
in the treated area simultaneously, creating
an uncoordinated contraction, which is
primarily isometric in nature. Voluntary
muscular contractions, on the other
hand, roll through the muscle in a wave to
generate a coordinated, directed force.
Kots was able to show, using a tensiometric
device, that the muscle tension produced
in a maximal EMS contraction can be up
to 30% higher than a maximal voluntary
contraction.
As far as muscle training was concerned,
EMS was initially only applied locally and
limited to certain muscle groups. What’s
more, the subject did not usually perform
any physical exercises while the EMS was
going on. This meant that they could quite
easily sit watching TV during the entire
process.
Localised EMS device - electrodes are embedded in
adhesive pads attached by a cable to the impulsegenerating equipment
Commercial, “over-the-counter” EMS
devices - such as the Swiss brand
Compex® and the US brand Slendertone
- are designed with overweight, nonathletic women in mind, as it takes power
to get through thick layers of fat. They are
therefore also ideal for top-level athletes
with very little fat.
Although localised devices continue to
be used today, for those wishing to use
EMS to achieve a full-body workout in less
than an hour, localised devices are not
considered practical.
This need to be able to apply EMS to
all major muscle groups simultaneously,
led to the development of full-body EMS
devices, where electrodes are embedded
into jackets, buttock belts and limb straps.
The leading provider of these devices is
a German company called miha bodytec,
founded in 2007. Since a certain amount
of training is required on these devices
before they can be used, miha bodytec only
sells them to commercial providers of EMS
training, who are trained to use the device
by miha bodytec itself.
1
EMS can be used as a physical training,
therapeutic and cosmetic tool. In medicine,
it is used for rehabilitation purposes, for
instance in physical therapy. It has, in
particular, been commended by various
research studies for its ability to relieve back
pain.
As a physical training tool, EMS is used
as a rehabilitation tool, as well as a
complementary tool to build muscle
strength, endurance and velocity, with
similar objectives to conventional training:
• To activate muscle hypertrophy for the
enhancement of maximum strength;
• To increase blood circulation and optmise
oxygen supply for increased endurance;
• To increase fast-twitch muscle fibres for
more explosive muscular power.
An additional objective of full-body EMS is
to achieve in 20 minutes what conventional
strength training achieves in two hours!
Studies on EMS and Muscle Strength
In recent years, various quantitative studies
have shown the positive effects of EMS
on muscle strengthening, in particular with
regard to the performance of fast-twitch
muscle fibres.
One such study, carried out in Germany in
20077, examined the Short- and longterm training effects on strength-related
diagnostic parameters from mechanical and
electrical stimulation. The study aimed to
compare classic strength training methods
with dynamic whole-body EMS.
80 sports students were randomly divided
into equal groups. The groups consisted
of classic training groups for hypertrophy,
maximum strength, quickness and
muscular endurance; groups for wholebody EMS and vibration; and two mixed
groups: whole-body EMS/hypertrophy and
vibration/hypertrophy.
The classic training groups worked on leg
curls and leg extensions, in sessions of 3
series with various additional weights (3090%) and between 3-15 repetitions. The
EMS groups executed side steps and knee
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The EMS/classic hypertrophy mixed
training group showed significantly lower
results than the non-mixed groups: a
maximum 7 % growth in strength and 12%
improvement in speed.
The study commented that combinations
of classic and modern training procedures
could thus open up new, promising
configurations of stimuli. It said longterm effects of whole-body EMS must in
particular be emphasised, as the greatest
boosts in performance appeared after a
two-week period of regeneration.
The study concluded that compared with
various types of training to boost strength
and speed, dynamic whole-body EMS
training with miha bodytec had shown
to be a highly effective training method.
Whole-body EMS was the sole form of
training able to improve maximum sports
performance in speed of movement. In
addition, pronounced long-term effects
were opening up new possibilities in training
periodisation. The study recommended a
carefully dosed amount of whole-body EMS
together with the dynamic execution of
movement as a promising combination for
strength and speed training.
Benefits of EMS for Athletes
The findings of the above, and other,
studies were, in general, endorsed and
applied by one of the most well-known
Olympic sprint coaches and personal
trainers: Charlie Francis. Francis - who died
in 2010 - was an avid supporter of EMS as
an important component in the training of
sprint athletes (although he preferred the
use of localised EMS devices).
According to Francis, the discovery back in the 1970s - that muscle tension
produced in a maximal EMS contraction
could be up to 30% higher than a maximal
He said that since individual muscle fibres
can be completely exhausted in just a few
seconds, the body has adopted several
strategies to prolong endurance. Slow
twitch (red) fibre is used first in voluntary
contractions, as it is energy efficient, though
not very powerful. Then only enough strong,
but voracious, fast twitch (white) fibre is
added to handle the load.
In addition, muscles work their individual
fibres in relays, always holding some
back from even the most demanding
load to maintain a reserve. Therefore, it is
impossible to voluntarily contract all fibres
simultaneously. The order of muscle fibre
recruitment makes it likely that most of the
fibres held in reserve will be white, said
Francis.
EMS, however, works directly on the
muscles, bypassing the body’s energy
conservation system, so there is no limit
to the percentage of fibre that can be
activated. The EMS stimulus “spills over”
from fully contracted fibre to activate
remaining fibre (given sufficient electrical
current), allowing the athlete to experience
a training stimulus that is unattainable by
any other means.
The supra-maximal nature of this exercise
enhances the strength to weight ratio by
favouring enhanced recruitment over crosssectional growth and also optimises fibresplitting and the conversion of intermediate
fibre to white fibre: the “Holy Grail” of power
training, said Francis.
Recruitment velocity is the rate at which a
muscle fibre can achieve maximum tension,
varying from 20 milliseconds for white fibre
to 65 milliseconds for red. Recruitment
rates vary since red fibre gets a “head start”
in voluntary contractions as white fibre is
only added in as needed once the load has
been determined.
EMS reverses the natural recruitment order,
said Francis, as its non-specific current
flows more easily through the bigger neuron
of the white fibre (less resistance) forcing
red and intermediate fibrer to shorten their
recruitment rates in response to white fibre
recruitment, which now precedes rather
than follows in the contraction.
According to Francis, the reversed
recruitment order combined with the
positive effects of high intensity make EMS
ideal for improving recruitment velocity
across all fibre types: a key factor in
explosive events such as sprinting.
b e fi t
Objectives of EMS
The study showed that all types of strength
training were able to significantly improve
maximum performance. It showed that
maximum strength improved the most by 16% - within the hypertrophy group,
followed by 9-10% for EMS. However,
only the EMS groups showed significant
improvement in speed. The measured
speed performance improved by about
30% - significantly more than by classic
methods (16-18%). This was due to EMS‘s
direct control of fast-twitch muscle fibres.
voluntary contraction made intuitive sense,
given the nature of the body’s energy
conservation system8.
an
The Miha Bodytec full-body EMS system
bends without additional weights (6 second
electrical pulses with 4 seconds’ rest in
between, at a pulse frequency of 85 Hz).
Standardisation was via visual biofeedback.
The training took place twice a week over
a period of four weeks. Entry and exit tests
were carried out on strength diagnostic
machines before and after the training
as well as after a two-week regeneration
phase. The dynamics were measured by
means of performance (strength x speed)
with 40% and 60% additional load at
various angles.
Ic
As opposed to localised EMS equipment,
which generally involves a passive form of
training where the subject hardly moves,
Miha Bodytec’s philosophy is to combine
EMS with physical movements.
2
Integrating EMS into a
Training Program for
Athletes
According to Charlie Francis, although
the benefits of EMS have been discussed
extensively in theory and demonstrated
in controlled studies, the real challenge is
the successful incorporation of EMS into a
training program.
He said although EMS is the single most
intense strength building, it has the
briefest improvement period of all training
modalities. Kots’ literature describes a
maximum strength gain plateau after 25
treatments (which could be administered
over four to seven weeks); however, in
Francis’ experience, most of the benefits
were achieved within ten treatments and
strength gains beyond fifteen treatments
were negligible. And since ten to fifteen
treatments maximise recruitment velocity,
it seems logical to work between these
numbers.
Strength is the foundation for sport-specific
tasks, therefore it must be established
early in an athlete’s sporting career.
Strength gains in the order of 25% per
year may be required in the first few years,
though the requirement drops rapidly
until top international athletes factor in
improvements of 6% per year or less. This
leads to the question: why don’t athletes
continue to push their strength work to the
limit throughout their careers?
High intensity training elements must
compete for CNS energy. A novice sprinter
can’t tax the CNS significantly no matter
how hard he tries, but as he improves, the
CNS demand rises exponentially, even if
the volume of sprinting remains constant.
Therefore, the degree of intensification of
other factors must be reduced over time if
speed is to improve further, said Francis.
As a result, he said EMS should be used
for strength development as soon as
fitness fundamentals are in place, with
a diminishing role in routine strength
enhancement as the career advances. A
quadrennial plan for a top sprinter might
include EMS strength building twice per
year during years one and two, reducing to
once during year three and only if needed in
year four.
He said EMS strength training, on the
quads, hamstrings, glutes, and erector
spinae, should coincide with maximal
strength weightlifting, as the two modalities
are synergistic.
The EMS training session prescribed
by Francis consists of a gentle pulsing
warmup where each muscle group is
stimulated maximally for ten repetitions of
ten seconds’ duration with a 50-second
rest between contractions. It is critical to
maintain these rest periods as this is the
absolute minimum recovery time needed to
maintain a maximal contraction on the next
rep. A shortened rest period may, in fact,
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change the nature of the exercise so that
it enhances the wrong fibre type, warned
Francis. The athlete must always control the
intensity of the contraction as the amount of
current necessary for a maximal contraction
varies widely between individuals.
He said it is, however, important for the
intensity to be as high as possible and
that most users never come near the level
of contraction they need for best results.
To understand the intensity the athlete
needs to experience, he should contract
the quads as hard as he possibly can
voluntarily, and then imagine a goal 30%
higher than that! He even had some of his
athletes biting down on a piece of leather
while being “stimmed”.
Francis was not, however a proponent of
the type of EMS equipment that allowed a
number of muscle groups to be stimulated
simultaneously - such as the whole-body
miha bodytec system. His philosophy
was to never work more than two muscle
groups at a time as the athlete had to be
able to determine where the stimulus was
coming from. He also instructed his athletes
to keep their limbs straight and unsecured,
allowing them to concentrate on the
contraction in isolation for learning reasons.
This is, again, in contradiction to the miha
bodytec system which combines EMS with
physical, voluntary movements.
Not all sprinters agree with him though,
as demonstrated by Usain Bolt, who uses
whole-body EMS as part of his training
regime.
Usain Bolt training with miha bodytec EMS
What About Bodybuilding?
According to Charlie Francis, EMS
increases muscular density or “hardness”
much like high intensity weight training. If
you slapped Ben Johnson on the back it
would be like hitting a brick wall; he was
as hard as a rock, not “puffy” like Arnold
Schwarzenegger. So the thing to think
about with EMS is density, not size. Think
of it as maximal strength training and not
hypertrophy training.
He also considers EMS to be for large
muscle groups only. Although an expert
might be able to pull it off, the average user
will not be able to use it on small muscle
groups like the biceps, triceps and calves.
These muscles will “roll up” on you, plus
even if you could do it (like by placing your
foot in a ski boot for calves) it would be
excruciating.
A Bodybuilder could also use EMS to help
him break through a barrier. For example, if
his body is weak as compared to his legs,
he could use EMS to maintain his legs for
a few weeks while focusing on upper body
training. He would be allowing all his body’s
recovery mechanisms and CNS to focus on
his upper body. He wouldn’t lose any size
in his legs and may even see improvement
in density.
Summary
In Charlie Francis’ words; “No, EMS will
not give you Arnold’s biceps while sitting
on the couch, but it does have many uses
in athletics, rehabilitation, and even for
bodybuilding. Just remember, crank it up!”
For top athletes and bodybuilders EMS has
proven to be an effective complementary
component in their training regimes - but
it could never be used on its own, with no
other training. Think about it: how could
you become a top sprinter or weightlifter
if you’ve never actually run 100 metres
or lifted a barbell? EMS alone would
never produce the level of hypertrophy
required to transform someone into Arnold
Schwarzenegger - or even Ben Johnson.
But let’s go back to the original question
posed at the beginning of this paper, that of
whether EMS training can entirely replace
the conventional strength training of the
average person.
While EMS cannot be used on its own by
top athletes to achieve their fitness goals, it
can certainly be considered as a viable sole
component of the average person’s training
regime … if that person’s goal is to achieve
a moderate level of muscle strength and
toning. And if, in addition, that person’s goal
is to spend as little time as possible training
to achieve that muscle toning, whole-body
EMS can be considered an ideal solution.
References
1 EMS Training at Riverside Fitness | Available at:
http://www.riversidefitness.com.au/emstraining.
2 BRIEF HISTORY OF ELECTRO-STIMULATION
- How to | Available at: http://www.itechmedicaldivision.com/en/brief_history_of_electro_stimulationt-2.html.
3 Luigi Galvani - Wikipedia, the free encyclopedia |
Available at: http://en.wikipedia.org/wiki/Luigi_Galvani.
4 Electrical muscle stimulation - Wikipedia, the free
encyclopedia | Available at: http://en.wikipedia.org/
wiki/Electrical_muscle_stimulation.
5 T NATION | Truth About EMS | Available at: http://
www.t-nation.com/free_online_article/sports_body_
training_performance/the_truth_about_ems&cr=.
6 HOW EMS WORKS | Body In Vest. | Available at:
http://bodyinvest.ca/?page_id=5183.
7 Speicher, U. / Nowak, S. / Schmithüsen J. /
Kleinöder, H. / Mester, J., German Sport University
Cologne 2008. | [Available at: http://studiotec.ca/
admin/Upload_PDF/4%20STUDIES%20Short%20
and%20long.pdf.
8 T NATION | Truth About EMS | Available at: http://
www.t-nation.com/free_online_article/sports_body_
training_performance/the_truth_about_ems&cr=.
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