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Does whole-body electrical muscle stimulation com-
bined with strength training promote morphofunc-
tional alterations?
Alexandre Lopes Evangelista
0000-0000-0000-0000
,
I,
* Caue
ˆVazquez La Scala Teixeira,
II
Bruna Massaroto Barros,
III
Jo
ˆnatas Bezerra de Azevedo,
III
Marcos Rodolfo Ramos Paunksnis,
III
Cleison Rodrigues de Souza,
IV
Tanuj Wadhi,
V
Roberta Luksevicius Rica,
VI
Tiago Volpi Braz,
VII
Danilo Sales Bocalini
0000-0000-0000-0000
VIII
I
Departamento de Educacao Fisica, Universidade Nove de Julho, Sao Paulo, SP, BR.
II
Grupo de Estudos da Obesidade, Universidade Federal de Sao Paulo,
Sao Paulo, SP, BR.
III
Programa de Pos Graduacao em Ciencias da Reabilitacao, Universidade Nove de Julho, Sao Paulo, SP, BR.
IV
Tecfit, Sao Paulo, SP, BR.
V
Health Sciences and Human Performance, University of Tampa, Tampa, Florida, USA.
VI
Departamento de Educacao Fisica, Universidade Estacio de Sa,
Vitoria, ES, BR.
VII
Laboratorio de Avaliacao do Movimento Humano, Universidade Metodista de Piracicaba, Piracicaba, SP, BR.
VIII
Laboratorio de Fisiologia
e Bioquimica Experimental, Centro de Educacao Fisica e Esporte, Universidade Federal do Espirito Santo, Vitoria, ES, BR.
Evangelista AL, Teixeira CVLS, Barros BM, de Azevedo JB, Paunksnis MRR, Souza CR, et al. Does whole-body electrical muscle stimulation combined with
strength training promote morphofunctional alterations? Clinics. 2019;74:e1334
*Corresponding author. E-mail: contato@alexandrelevangelista.com.br
OBJECTIVES: The aim of this study was to evaluate the effects of 8 weeks of strength training (ST) combined
with whole-body electrical stimulation (EMS) on morphofunctional adaptations in active individuals.
METHODS: Fifty-eight volunteers were randomly distributed into the following groups: an untrained control
(UN) group (n=16), an ST group (n=21) or an ST combined with EMS (ST+EMS) group (n=21). Both intervention
groups (the ST and ST+EMS groups) performed 3 exercises (biceps curl, back squats and high-pulley tricep
extensions) twice a week for 8 weeks. The subjects performed 3 sets of 8 to 12 maximum repetitions (MRs) with a
90-second rest duration between sets. The ST+EMS group performed the resistance training exercises wearing a
whole-body suit that provided electrical stimulation at frequencies between 80-85 Hz, with a continuously
bipolar impulse duration and pulse breadth of 350 ms. The intensity for each muscle group was controlled by
Borg’s category ratio (CR)-10 scale; the intensity started at 5-6 and eventually reached 7-8. One-repetition
maximum strength (1RM) and muscle thickness (MT) were measured before and after the training intervention.
MT was evaluated in the biceps brachii (BB), triceps brachii (TB), and vastus lateralis (VL).
RESULTS: No differences (p40.05) were found between the ST and ST+EMS groups. Improvements (po0.05) in
the absolute values of the morphofunctional parameters after the training protocol were observed. Significant
differences were found between both the intervention groups and the UN group (po0.05). The ST+EMS group
presented high percentage changes (po0.05) in muscular strength for the 1RM
squat
(43.2%, ES=1.64) and the
MT of the BB (21.6%, ES=1.21) compared to the ST (20.5%, ES=1.43, 11.9%, ES=0.77) group.
CONCLUSIONS: Our data suggest that the combination of ST+EMS may promote alterations in muscle strength
and MT in healthy active subjects.
KEYWORDS: Muscle Strength; Resistance Training; Muscle Hypertrophy; Maximal Strength; Neuromuscular
Adaptation.
’INTRODUCTION
The regular practice of diverse physical exercise methods
is associated with numerous health-related benefits, such as a
reduction in body fat (1), the addition of lean mass (2), an
improvement in self-esteem (3) and increased functional
capacity (4).
As such, varying interventions have been developed to
promote motivation to engage in physical exercise (5) and to
maximize the results of more traditional interventions.
Among these strategies, physical training using whole-body
electrical muscle stimulation (EMS) has gained popularity.
Whole-body EMS is a relatively new training technology that
differs fundamentally from the classic passive and locally
applied EMS used for therapeutic (6-9) and sport (10,11)
purposes. Modern devices, such as the whole-body suit, have
the ability to stimulate all the major muscle groups either in
isolation or simultaneously (i.e., up to an area of 2.800 cm
2
)
and therefore have been increasingly applied in training
programs for health promotion, aesthetic improvement and
physical fitness and performance improvement.
DOI: 10.6061/clinics/2019/e1334
Copyright &2019 CLINICS –This is an Open Access article distributed under the
terms of the Creative Commons License (http://creativecommons.org/licenses/by/
4.0/) which permits unrestricted use, distribution, and reproduction in any
medium or format, provided the original work is properly cited.
No potential conflict of interest was reported.
Received for publication on May 1, 2019. Accepted for publication
on August 18, 2019
1
ORIGINAL ARTICLE
The favorable effects of EMS on body composition and
physical fitness parameters have been reported in several
studies (5). The benefits associated with EMS include the
reduction in sarcopenia (12-14), diseases associated with type
II diabetes (15) and visceral fat in sedentary individuals with
obesity (16). In addition, EMS has been used in a wide variety
of populations to improve athletic performance, body compo-
sition, functionality and quality of life (1,17).
However, to date, EMS in combination with other inter-
ventions to maximize physical training results has not been
studied. Among these interventions, strength training (ST)
combined with EMS seems to be the most promising since ST
is considered the most effective means of increasing strength
and muscle tissue hypertrophy (1). Thus, the objective of the
present study was to verify the chronic effect of ST plus
electrostimulation on the strength and muscle thickness (MT)
of physically active subjects. The hypothesis is that the use of
EMS during ST will potentiate the effects found with ST alone.
’METHODS
Experimental Approach to the Problem
A randomized, parallel-group, repeated-measures design
was used to investigate the effects of traditional ST, ST
combined with whole-body EMS (ST+EMS) and a nontrain-
ing control (UN) on morphofunctional adaptations. Both of
the training groups (ST and ST+EMS) trained twice a week
for 8 weeks. The subjects performed 3 sets of 8 to 12 maxi-
mum repetitions with a 90-second rest duration between
sets. The total number of sets and repetitions were equal
between the groups; however, the ST+EMS group perfor-
med the resistance training exercises while wearing a whole-
body suit that provided EMS stimuli. Maximum strength
and MT were assessed before and after the 8-week training
period using one-repetition maximum (1RM) and ultrasono-
graphy assessments of the biceps brachii (BB), triceps brachii
(TB) and vastus lateralis (VL) muscles.
Subjects
After approval from the committee of ethics and research
of the local institution (protocol number: 2.313.847/2018),
sixty-six healthy, physically active subjects volunteered to
participate in this study. The exclusion criteria were as
follows: subjects with a positive clinical diagnosis of diabetes
mellitus, subjects who smoked, and subjects with muscu-
loskeletal complications and/or cardiovascular issues con-
firmed by medical evaluation.
The volunteers were randomly distributed to one of three
groups: an UN group (n=16), an ST group (n=25) or an ST
+EMS group (n= 25). During the study period, 8 individuals
dropped out of the ST and ST+EMS groups for personal
reasons, leaving 21 subjects in each of the two groups inclu-
ded in the statistical analysis, as shown in Table 1. None of
the participants had engaged in resistance training for at
least six months prior to the experimental period but physi-
cally participated in other types of activities (recreational
sports and/or endurance training) according to the Interna-
tional Physical Activity Questionnaire (IPAQ).
’METHODS
Maximum Strength
Maximum dynamic strength was assessed with 1RM
testing during biceps curl, back squat and high-pulley tricep
extension exercises (Nakagym
s
, São Paulo, Brazil). The
testing protocol followed previous recommendations by Haff
and Triplett (18). Subjects reported to the laboratory having
refrained from any exercise other than activities of daily
living for at least 72 hours prior to the testing sessions both
before and after the intervention.
In brief, subjects warmed up for 5 minutes on a treadmill
(Movement technology
s
, São Paulo, Brazil) at 60% of their
maximum heart rate followed by two exercise-specific warm-
up sets. During the first set, the subjects performed five
repetitions at B50% of the estimated 1RM followed by one
set of three repetitions at a load corresponding to B60-80%
of the estimated 1RM, with a 3-minute rest interval between
sets. Following the warm-up sets, subjects made five attempts
to find their 1RM load, with 3-minute intervals between trials.
The 1RM was defined as the maximum weight that could be
lifted no more than once with a proper technique. Verbal
encouragement was given throughout testing. All the testing
sessions were supervised by the research team for validity.
The test-retest intraclass correlation coefficients (ICCs) calcu-
lated for the data collected during the familiarization and
preintervention period for the 1RM
biceps curl
, 1RM
squat
, and
1RM
elbow extension
were 0.989, 0.990, and 0.988, respectively.
The coefficients of variation (CVs) for these measures were
0.8, 0.7, and 0.9%, respectively. The standard errors of mea-
surement (SEMs) for these measures were 2.05, 1.95, and
2.23 kg, respectively.
Muscle Thickness Assessment
Ultrasonography was used to determine the MT of the
biceps brachii and brachialis (BB), TB and VL using an
ultrasound-imaging unit (Bodymetrix, BodyMetrix, BX2000,
IntelaMetrix, Inc., Livermore, CA) with a wave frequency of
2.5 MHz. The ultrasound probe was applied perpendicular
to the skin for measurement. A water-soluble gel was used
on the transducer to aid acoustic coupling and remove the
need for excess contact pressure on the skin. MT was defined
as the distance between the interface of the muscle tissue and
subcutaneous fat to the corresponding bone. Imaging was
performed on the right side of the body. The subjects were
instructed to fast for at least 3 hours prior to testing, and pre-
and posttesting assessments were performed at the same
time of day.
The BB and TB assessments were performed at a distal
point located at 60% of the distance from the lateral epicon-
dyle of the humerus to the acromion process of the scapula.
The VL assessments were performed midway between the
lateral condyle of the femur and the greater trochanter. For
the upper body assessments, the subject’s arms were placed
by their sides in a relaxed position while they sat com-
fortably. For the lower body assessments, the subjects rested
in a supine position on an examination bed with their knees
Table 1 -Sample characteristics.
Parameters UN ST ST+EMS
Age (years) 27.1±4.1 25.1±3.2 25.5±6.1
Body mass (kg) 78.8±12.9 78.1±15.3 78.1±7.5
Height (cm) 177±0.08 175±0.07 176±0.06
Values are expressed as the means ±standard deviations (SDs) for the
untrained control (UN), strength training (ST) and strength training
combined with EMS (ST+EMS) groups.
2
Whole-body electrical stimulation and strength training
Evangelista AL et al.
CLINICS 2019;74:e1334
fully extended and relaxed. The legs were strapped to each
other and to the table to minimize unwanted movement.
The MT was assessed by the same blinded researcher pre-
and posttest; the researcher was careful to apply minimal
pressure when placing the probes on the subject’s skin. To
increase test-retest consistency, each site was marked with
henna ink and remarked every week. Additionally, in an
effort to ensure that swelling of the muscles after training did
not obscure the results, images were obtained 48-72 hours
before commencement of the study and 48-72 hours after the
final training session. This is consistent with research show-
ing that an acute increase in MT returns to baseline within
48 hours of an ST session (19). To further ensure the accuracy
of the MT assessments, at least three images were obtained
for each region. The test-retest ICCs for the TB, BB, and VL
were 0.998, 0.996, and 0.999, respectively. The CVs for these
measurements were 0.6, 0.4, and 0.6%, respectively. The
SEMs for these measurements were 0.42, 0.29, and 0.41 mm,
respectively.
Familiarization
All the subjects completed two familiarization sessions
separated by a minimum of 72 hours before the commence-
ment of the experimental protocol; both sessions occurred
one week after the maximum dynamic strength and muscle
thickness assessments. During these sessions, subjects were
familiarized with the exercises and proper techniques.
Training Regimens
The subjects underwent a hypertrophy-oriented ST regimen
twice a week (at least 48 hours between training sessions) for 8
weeks. The target intensity was 8 to 12 maximum repetitions
(MRs) for each exercise. Three sets were performed for each of
the following exercises: biceps curl back squats and high-
pulley tricep extensions. The exercises were performed with a
free repetition tempo, and a 90-second rest interval was
allowed between sets. The exercises and repetition schemes
remained the same for all 8 weeks in both groups. If a subject
was unable to complete the required repetitions, the load was
dropped by 2-10% for the upper body and 2-15% for the lower
body exercises. On the other hand, if a subject was able to
perform one or two more repetitions (i.e., 13-14 repetitions),
the load was increased by 2-10% for the upper body and
2-15% for lower body exercises (20). Each training session
lasted approximately 20 minutes.
The ST+EMS group performed the same training regimen
with the addition of whole-body EMS provided by a suit
(XBody
s
, Dorsten, Nordrhein-Westfalen, Germany). The
EMS suit stimulated 5 muscle groups during the ST exercises
(the biceps during the biceps curl exercise; the quadriceps,
hamstrings and glutes during the back squat exercises; and
the triceps during the high-pulley tricep extension exercises).
The intensity of the EMS current progressively increased
during the interventional period (Table 2). The subjects were
asked to rate the average intensity of the EMS session and
the regional intensity of the EMS on a rating scale (Ratings
of Perceived Exertion [RPE]); the intensity was maintained
between 5-6 for weeks 1 and 2 and increased to 7-8 for weeks
3to8.
The subjects were asked to refrain from performing any
type of additional exercise regimen throughout the study
duration. Research staff supervised all training sessions,
provided verbal encouragement and ensured that the sub-
jects performed the correct number of sets and repetitions
with the correct exercise technique.
Statistical Analyses
The normality and homogeneity of the data were verified
using the Shapiro-Wilk and Levene tests, respectively. Prior
to analysis, all the data were log-transformed to reduce bias
arising from nonuniformity errors (heteroscedasticity). The
means, SDs and 95% confidence intervals (CIs) were calcu-
lated for the normally distributed data. A repeated-measures
2x3 analysis of variance (ANOVA) was used to compare the
1RM
biceps curl
, 1RM
squat
, 1RM
elbow extension
, and MT of the BB,
TB and VL using the groups as fixed factors and the subjects
as random factors. Post hoc comparisons were performed
with a Bonferroni correction. Assumptions of sphericity were
evaluated using Mauchly’s test; if sphericity was violated
(po0.05), the Greenhouse-Geisser correction factor was
applied. In addition, effect sizes (ESs) were evaluated using
a partial eta squared (Z
2p
), with o0.06, 0.06 to 0.14 and
40.14 indicating a small, medium, and large effect, respec-
tively. Cohen’s d was calculated as the difference in the means
divided by the pooled standard deviation (d¼xPostxPre
SDPooled )to
measure the absolute differences (pre vs posttest) in the raw
values of the variables (4). The results from Cohen’sdwere
qualitatively interpreted using the following thresholds:
o0.2, trivial; 0.2 - 0.6, small; 0.6 -1.2, moderate; 1.2 - 2.0,
large; 2.0 - 4.0, very large and; 44.0, extremely large. If the
90% confidence limits overlapped, small positive and nega-
tive values for the magnitude were deemed unclear; other-
wise, the observed magnitude was deemed acceptable (10).
The trivial area (do0.2, gray bar) is marked in forest plot
graph. All analyses were conducted using SPSS-22.0 (IBM
Corp., Armonk, NY, USA). The adopted significance was
pp0.05.
’RESULTS
As shown in Table 3, significant main effects of time
(F
1,15
=74.437, po0.001, Z
2p
=0.832) and the group x time
interaction (F
2,30
=26.666, po0.001, Z
2p
=0.640) were observed
for the 1RM
biceps curl
. There were significant differences in
time (F
1,15
=214.970, po0.001, Z
2p
=0.935) and the group x
time interaction (F
2,30
=59.405, po0.001, Z
2p
=0.798) for the
1RM
squat
. Significant main effects of time (F
1,15
=72.417,
po0.001, Z
2p
=0.828) and the group x time interaction
(F
2,30
=24.021, po0.001, Z
2p
=0.616) were observed for the
1RM
elbow extension
.
Significant main effects of time (F
1,15
=46.977, po0.001,
Z
2p
=0.758) and the group x time interaction (F
2,30
=27.510,
p=0.038, Z
2p
=0.521) were observed for the BB. There were
significant differences in time (F
1,15
=115.319, po0.001,
Z
2p
=0.885) and the group x time interaction (F
2,30
=34.458,
Table 2 -Electrical stimulation protocol.
Program variables Weeks 1 and 2 Weeks 3 to 8
Stimulation frequency 80 Hz 85 Hz
Impulse duration continuously continuously
Pulse breadth 350 ms 350 ms
Impulse type bipolar bipolar
Duration B20 minutes B20 minutes
Regional intensity (Borg’s CR-10 scale) 5-6 7-8
3
CLINICS 2019;74:e1334 Whole-body electrical stimulation and strength training
Evangelista AL et al.
p=0.038, Z
2p
=0.703) for the TB. Significant main effects of
time (F
1,15
=73.302, po0.001, Z
2p
=0.830) and the group x time
interaction (F
1.343,20.142
=11.196, p=0.038, Z
2p
=0.427) were
observed for the VL, as shown in Table 4.
Figure 1 represents the results of the Cohen’sdESs.
The absolute differences after 8 weeks of training between the
UN vs ST+EMS group were large for the 1RM
elbow extension
(d=1.82, 90% CI=1.31 to 2.33), BB (d=1.90, 90% CI=1.47 to
2.33) and VL (d=1.65, 90% CI=1.20 to 2.10) and very large
for the 1RM
biceps curl
(d=2.19, 90% CI=1.75 to 2.63), 1RM
squat
(d=3.51, 90% CI=2.84 to 4.18) and TB (d=2.34, 90% CI=1.06
to 3.02).
The differences between the UN vs ST groups were large
for the 1RM
biceps curl
(d=1.36, 90% CI=0.91 to 1.81), 1RM
elbow
extension
(d=1.87, 90% CI=1.24 to 2.45), BB (d=1.69, 90%
CI=1.25 to 2.13) and TB (d=1.31, 90% CI=0.80 to 1.82) and
very large for the 1RM
squat
(d=2.33, 90% CI=1.80 to 2.86) and
VL (d=2.18, 90% CI=1.57 to 2.79). In comparison, the ESs of
the ST vs ST+EMS groups were moderate for the 1RM
biceps
curl
, BB and TB (do1.2), favoring the ST+EMS group.
A large ES for the 1RM
squat
was found in the ST vs ST+EMS
groups (d=1.63, 90% CI=1.27 to 1.99).
’DISCUSSION
The present study aimed to investigate the chronic effects
of 8 weeks of ST combined with EMS on maximal strength
and MT in physically active individuals. To the best of our
knowledge, this is the first study to analyze traditional ST in
combination with EMS. EMS has been applied with different
approaches, such as in therapeutic (6-9), sports (10-11) prac-
tices, and has shown positive results in reducing sarcopenia
(15), diabetes (12) and obesity in sedentary individuals with
obesity (16).
The results showed that both training protocols (ST and
ST+EMS) resulted in a significant improvement in all the
studied variables (strength and MT) compared to the con-
trol group (po0.05 for all variables). However, although
ANOVA revealed no significant differences between the
Table 3 -Muscle strength parameters after 8 weeks of training.
Parameters Pre Post D% Cohen’s d ANOVA 3x2
time time*group
ES pvalue pvalue
1RM
biceps curl
(kg)
UN 33±933
±9 2.7 0.10 0.176
ST 33±10 38±10
a#
15.1 0.50 o0.001
ST+EMS 34±10 43±12
a#
24.3 0.77 o0.001 o0.001
1RM
squat
(kg)
UN 92±11 91±11 -1.1 -0.09 0.292
ST 92±12 111±14
a#
20.5 1.43 o0.001
ST+EMS 93±18 133±30
a#
43.2 1.64 o0.001 o0.001
1RM
elbow extension
(kg)
UN 27±527
±6 1.6 0.08 0.269
ST 27±933
±10
a#
22.1 0.62 o0.001
ST+EMS 28±734
±6
a#
21.2 0.90 o0.001 o0.001
Values are expressed as the mean ±the standard deviation (SD) for the untrained (UN), strength training (ST) and strength training combined with
whole-body EMS (ST+EMS) groups. One-repetition maximal strength (1RM). Effect size (ES).
a
Significant (po0.05) differences compared to before training.
#
Significant (po0.05) differences compared to the UN group.
Table 4 -Muscle thickness (MT) measurements after 8 weeks of training.
Parameters Pre Post D% Cohen’s d ANOVA 3x2
time time*group
ES pvalue pvalue
BB (mm)
UN 34.0±3.3 34.4±3.4 1.2 0.12 0.214
ST 32.6±7.1 36.5±4.8
a#
11.9 0.77 o0.001
ST+EMS 33.2±6.1 40.4±5.8
a#
21.6 1.21 o0.001 0.038
TB (mm)
UN 33.5±3.0 34.0±3.1 1.4 0.16 0.248
ST 33.1±4.3 36.1±5.1
a#
9.1 0.64 o0.001
ST+EMS 31.5±5.3 36.8±5.6
a#
16.8 0.97 o0.001 0.038
VL (mm)
UN 40.9±5.2 41.0±5.4 0.4 0.03 0.142
ST 41.4±5.5 46.8±4.6
a#
13.0 1.06 o0.001
ST+EMS 40.9±5.9 46.2±5.2
a#
12.9 0.95 o0.001 0.038
Values expressed as the mean ±standard deviation (SD) for the untrained (UN), strength training (ST) and strength training combined with body electric
stimulation (ST+EMS) groups. Muscle thickness (MT) of the biceps brachii and brachialis (BB), triceps brachii (TB) and vastus lateralis (VL). Effect size (ES).
a
Significant (po0.05) differences compared to before.
#
Significant (po0.05) differences compared to the UN group.
4
Whole-body electrical stimulation and strength training
Evangelista AL et al.
CLINICS 2019;74:e1334
training protocols, percentage changes and effect sizes in the
ST+EMS group presented higher gains for elbow flexor
strength when compared to the ST group (D%=24.3%,
ES=0.77 vs.D%=15.1%, ES=0.50, respectively). The results
also suggest that the strength of the lower limbs can benefit
from the addition of EMS (ST+EMS: D%=43.2%, ES=1.64 vs.
ST: D%=20.5%, ES=1.43).
Regarding muscle hypertrophy, there were greater percen-
tage gains and effect sizes for the BB and TB variables in the
ST+EMS group than in the ST group (ST+EMS BB: D%=
21.6%, ES=1.21 vs ST BB: D%=1.9%, ES=0.77, and ST+EMS
TB: D%=16.8%, ES=0.97 vs ST TB: D%=9.1%, ES=0.64), simi-
lar to strength.
These findings are in line with the study by Ahmad and
Hasbullah (21), who demonstrated gains in both strength
and muscle mass by subjecting 15 physically active indivi-
duals to 5 weeks of EMS training. The sessions lasted for
20 minutes twice a week, similar to those in this study.
According to the authors, the addition of EMS to resistance
training generated an increase in the mechanical stress and,
consequently, in the pattern of recruitment of the motor units.
Increased mechanical stress has been postulated as one of
the main stimuli for the process of myofibrillar protein syn-
thesis and consequent muscle hypertrophy (22). In addition,
the possible additional recruitment of muscle fibers resulting
from the combination of EMS and ST can maximize energy
expenditure and metabolic stress. In this case, metabolic
stress has been noted as one of the factors that contributes to
the increase in the cross-sectional area of the muscle (23).
Kemmler et al. (23) pointed out that the addition of EMS
to resistance training seemed to be effective in relation to
muscular adaptation. The authors also compared the effects
of traditional training (a combination of resistance exercises
plus endurance exercises performed 2 times a week) with
training combined with EMS (traditional training plus 20
minutes of EMS). The results of the study demonstrated that
the 20-minute exercise plus EMS regimen was more effective
for strength gains and lean mass maintenance than tradi-
tional isolation training. Thus, the authors considered the
application of this new exercise technology as an alternative
for individuals interested in increasing the functional and
morphological adaptations obtained from ST. These data
show that EMS is an effective means of physical training that
focuses on neuromuscular and morphological adaptations
and should be considered as an option by fitness instructors
and those interested in rehabilitation.
In the present study, it should be noted that although the
ST+EMS group presented increased percentage changes and
ESs for muscle strength and thickness, there was no signi-
ficant difference between the interventions, leading us to
believe that a longer intervention time is necessary for signi-
ficant differences to be observed in the study population.
This hypothesis needs to be tested in future studies. Other
limitations are also important to consider. We had a relatively
small sample size, and no EMS control group was included.
Additionally, caloric intake is an important factor; although
all the subjects in the study were instructed not to alter
their dietary intake and/or caloric consumption during the
training intervention, these data were not collected or strictly
monitored. Another important point to note is that the
subjects were physically active but did not regularly parti-
cipate in resistance training; therefore, these results should be
considered with caution when applying them to individuals
who engage in resistance training.
Despite these limitations, our data suggested positive
alterations in the morphofunctional parameters and warrant
further research on effective EMS practices and the effects of
different training method combinations in various popula-
tions. However, some limitations should be addressed; the
sample size was relatively small, and this was a short-term
study with no information about long-term outcomes. Des-
pite the significant induction of positive changes found in
this study, more studies are needed to examine the effects of
EMS in different healthy populations.
Our findings showed that the combination of EMS and ST
did not harm muscular adaptations after 8 weeks. As such,
strength and conditioning professionals as well as fitness
instructors working with healthy untrained subjects may
consider adding EMS to regular ST regimens as a strategy for
muscular adaptation.
Figure 1 - Cohen
´s effect size (ES) principle ±90% confidence intervals (CIs) were used to compare the absolute differences between
the untrained (UN), strength training (ST) and strength training combined with body electric stimulation (ST+EMS) groups considering
the one-repetition maximal strength test (1RM) and the muscle thickness (MT) of the biceps brachii and brachialis (BB), triceps brachii
(TB) and vastus lateralis (VL). *Large ES **Very large ES.
5
CLINICS 2019;74:e1334 Whole-body electrical stimulation and strength training
Evangelista AL et al.
’AUTHOR CONTRIBUTIONS
Each author made significant individual contributions to this manuscript.
Evangelista AL and Teixeira CVLS conceived the study, acquired and
interpreted the data, and drafted the manuscript. Barros BM, de Azevedo JB
and Wadhi T interpreted the data and drafted and reviewed the manuscript.
Souza CR conceived the study, acquired and interpreted the data. Paunksnis
MRR, Rica RL and Braz TV analyzed the data and reviewed the
manuscript. Evangelista AL and Bocalini DS conceived the study, acquired
and interpreted the data, drafted and reviewed the manuscript.
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