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The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40); 60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre, post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and 19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p > .05). G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p < .05). There was time effect for elbow flexion and unilateral leg press strength for all groups post-12 weeks (p < .05). However, the magnitude of increase was higher in G60 and G80. In conclusion, when low to high intensities of RT are performed with volume-matched, all intensities were effective for increasing muscle strength and size; however, 20% 1RM was suboptimal in this regard, and only the heavier RT intensity (80% 1RM) was shown superior for increasing strength and CSA compared to low intensities.
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European Journal of Sport Science
ISSN: 1746-1391 (Print) 1536-7290 (Online) Journal homepage: http://www.tandfonline.com/loi/tejs20
Effects of different intensities of resistance
training with equated volume load on muscle
strength and hypertrophy
Thiago Lasevicius, Carlos Ugrinowitsch, Brad Jon Schoenfeld, Hamilton
Roschel, Lucas Duarte Tavares, Eduardo Oliveira De Souza, Gilberto
Laurentino & Valmor Tricoli
To cite this article: Thiago Lasevicius, Carlos Ugrinowitsch, Brad Jon Schoenfeld, Hamilton
Roschel, Lucas Duarte Tavares, Eduardo Oliveira De Souza, Gilberto Laurentino & Valmor
Tricoli (2018): Effects of different intensities of resistance training with equated volume
load on muscle strength and hypertrophy, European Journal of Sport Science, DOI:
10.1080/17461391.2018.1450898
To link to this article: https://doi.org/10.1080/17461391.2018.1450898
Published online: 22 Mar 2018.
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ORIGINAL ARTICLE
Effects of different intensities of resistance training with equated volume
load on muscle strength and hypertrophy
THIAGO LASEVICIUS
1,2
, CARLOS UGRINOWITSCH
2
, BRAD JON SCHOENFELD
3
,
HAMILTON ROSCHEL
2
, LUCAS DUARTE TAVARES
1,2
, EDUARDO OLIVEIRA DE
SOUZA
4
, GILBERTO LAURENTINO
2
, & VALMOR TRICOLI
2
1
Department of Health Sciences, University Ibirapuera, São Paulo, Brazil;
2
Department of Sport, School of Physical Education
and Sport, University of São Paulo, São Paulo, Brazil;
3
Department of Health Sciences, CUNY Lehman College, Bronx, NY,
USA &
4
Department of Health Sciences and Human Performance, The University of Tampa, Tampa, FL, USA
Abstract
The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press
one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT
programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm
trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40);
60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number
of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre,
post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and
19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p> .05).
G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p< .05). There
was time effect for elbow flexion and unilateral leg press strength for all groups post-12 weeks (p< .05). However, the
magnitude of increase was higher in G60 and G80. In conclusion, when low to high intensities of RT are performed with
volume-matched, all intensities were effective for increasing muscle strength and size; however, 20% 1RM was suboptimal
in this regard, and only the heavier RT intensity (80% 1RM) was shown superior for increasing strength and CSA
compared to low intensities.
Keywords: Low-load, high-load, volume of training, muscle size
Highlights
.Resistance training with intensity ranging 2080% 1RM are effective to increase strength and muscle hypertrophy.
However, low intensity (20% 1RM) was suboptimal for maximizing muscle hypertrophy.
.A wide spectrum of intensities, from 4080% 1RM, are viable options to increase muscle mass. It is feasible that employing
combinations of these intensities may enhance hypertrophic results, as well as allow for better recovery by alleviating joint-
related stresses from continuous heavy-load training.
.The initial 6 weeks of training all the studied intensities can produce increases in strength in men with no experience in
resistance training. However, if maximizing strength gains over the long-term training is a primary goal, it is necessary
employ higher training intensities.
Introduction
Resistance training (RT) is the primary mode of exer-
cise to increase muscle strength and hypertrophy in
humans. These increases can positively impact the
ability to carry out daily activities (FitzGerald et al.,
2004;Rantanenetal.,2002)aswellassignificantly
improve overall health and wellness. Additionally, RT
has been shown to be an important strategy for enhan-
cing physical performance in athletics (Los Arcos et al.,
2014; Markovic, Jukic, Milanovic, & Metikos, 2007;
Pareja-Blanco, Rodríguez-Rosell, Sánchez-Medina,
Gorostiaga, & González-Badillo, 2014).
Variables of an RT programme such as rest inter-
val, frequency, volume, and intensity can be
© 2018 European College of Sport Science
Correspondence: Thiago Lasevicius, Department of Health Sciences, University Ibirapuera, C/Av. Interlagos, 1329, Chácara Flora São
Paulo PC 04661-100, São Paulo, Brazil. E-mail: lasevicius.thiago@gmail.com
European Journal of Sport Science, 2018
https://doi.org/10.1080/17461391.2018.1450898
manipulated to induce muscular adaptations (Amer-
ican College of Sports Medicine, 2009; Schoenfeld,
Grgic, Ogborn, & Krieger, 2017). With respect to
intensity, training with loads equating to 6585% of
maximum dynamic strength (1RM) has been rec-
ommended to increase strength and muscle mass
(American College of Sports Medicine, 2009). Alter-
natively, several studies have shown that low to moder-
ate intensities (3050% 1RM) promote similar gains
in muscle mass compared to training with higher
intensities (Lamon, Wallace, Leger, & Russell, 2009;
Leger et al., 2006;Mitchelletal.,2012; Ogasawara,
Loenneke, Thiebaud, & Abe, 2013;Schoenfeld,
Peterson, Ogborn, Contreras, & Sonmez, 2015).
Mitchell et al. (2012) found that leg extension exercise
performed at 30% 1RM until failure similarly
increased quadriceps muscle volume compared to
high-intensity exercise (80% 1RM) and was superior
to a 30% 1RM non-failure condition. The authors
speculated that this finding was due to complete
recruitment of the motor unit pool when low-intensity
exercise is performed to volitional failure and with a
large volume of training (VT). Alternatively, high-
intensity RT resulted in superior strength gains com-
pared to low-intensity exercise (Mitchell et al.,
2012). Intriguingly, electromyography research
shows greater muscular activation in high- versus
low-intensity RT (Schoenfeld, Contreras, Willardson,
Fontana, & Tiryaki-Sonmez, 2014), suggesting that
full spectrum of motor units may not be fully stimu-
lated when training at lower intensity.
Many studies have sought to compare muscular
adaptations with low- versus high-intensity RT.
Some have found greater increases in muscle hyper-
trophy with heavier intensity (Campos et al., 2002;
Holm et al., 2008; Schuenke et al., 2012), while
others showed no significant differences between
low and high intensity (Lamon et al., 2009; Leger
et al., 2006; Mitchell et al., 2012; Ogasawara
et al., 2013; Popov et al., 2006; Schoenfeld et al.,
2015; Tanimoto et al., 2008; Tanimoto & Ishii,
2006). A confounding issue in the majority of
these studies is that VT was not equated between
groups, and the few studies that endeavoured to
do so all used the VT of the high-intensity group
as the standard for the low-intensity group, which
resulted in lower volumes for both groups and
thus potentially limited muscular adaptations. It is
well established that the VT plays an important
role in muscular adaptations, with evidence of a
doseresponse relationship between volume and
hypertrophy (Schoenfeld, Ogborn, & Krieger,
2017). Thus, when different intensities of RT are
performed, VT must be matched at sufficiently
high levels to help ensure maximal responses for
each training condition.
The present study aimed to investigate the effect of
different intensities of RT across a wide spectrum of
loading zones with matched VT on 1RM and
muscle cross-section area (CSA) in response to 12-
weeks of RT. We hypothesized that intensities
between 40% and 80% 1RM would produce similar
hypertrophic responses and 20% would be below
the intensity threshold needed to maximize adap-
tations. Moreover, it was hypothesized that higher
intensities (6080% 1RM) would have greater
effects on muscle strength when compared to lower
intensities (2040% 1RM) of RT.
Methods
Experimental procedures
To determine the effect of different intensities of
RT on increases 1RM and CSA of the vastus later-
alis (VL) and elbow flexors (EF), a within-subject
design was employed in which one leg and arm
was set at 20% 1RM (G20) for all participants and
the contralateral limb was randomly assigned to
one of the three possible conditions: 40% 1RM
(G40); 60% 1RM (G60), and 80% 1RM (G80).
All participants performed two sessions per week
of unilateral elbow flexion (arm curl) and unilateral
leg press 45° for 12 weeks. Participants performed
three sets of G20 first each workout, with each set
taken to volitional failure. VT (sets × repetition ×
load) for G20 was recorded and used to match
the VT for the higher intensity condition in the
contralateral limb (i.e. G40, G60, and G80).
Unilateral arm curl and unilateral leg press 45°
1RM, as well as CSA of the VL and EF were
assessed at pre, post-6 weeks, and post-12 weeks
of training.
Subjects
Thirty health young men (age = 24.5 ± 2.4 years;
height = 180.0 ± 0.7 cm; body mass = 77 ± 16.5 kg)
volunteered to participate in this study. The sample
was determined by a post hoc power analysis based
on the previous research from our lab using VL
CSA as the outcome measure with a target effect
size difference of 0.6 and an alpha of 0.05, resulting
in a power of 0.82. Participants were recreationally
active with no experience in RT. All participants
were made aware of the procedures, benefits and
potentialsrisks,andthensignedaninformed
consent document to participate in this investi-
gation. This study was conducted according to the
Declaration of Helsinki, and the Institutions
Research Ethics Committee approved the exper-
imental protocol.
2T. Lasevicius et al.
Muscle CSA
Muscle CSA was determined for the EF and VL
using B-mode ultrasonography with a 7.5 MHz
linear-array probe (SonoAce R3, Samsung-
Medison, Gangwon-do, South Korea). A researcher
experienced in muscle ultrasound testing performed
all measurements. To measure EF CSA, the
researcher first identified the midpoint between the
head of the humerus and the lateral epicondyle of
the humerus, which was then marked with semiper-
manent ink for reference. Thereafter, the skin was
transversally marked every 1 cm from the reference
point along the medial and lateral aspects of the
upper arm to orient ultrasound probe placement.
For the VL CSA, the researcher identified the mid-
point between the greater trochanter and the lateral
epicondyle of the femur. The skin was then transver-
sally marked every 2 cm from the reference point
along the medial and lateral aspects of the thigh to
orient probe placement.
For measures of both EF and VL, sequential ultra-
sound images were acquired by aligning the head of
the probe with each mark on the skin following a
middle-to-lateral direction. A generous amount of
gel was applied to the probe to enhance conductivity
and care was taken to avoid depressing the skin
surface while scanning. After collecting this data,
the EF and VL images were digitally reconstructed.
Specifically, the images were sequentially opened in
power point (Microsoft, USA), and then each image
was manually rotated until the fascia of the EF and
VL muscles were modelled (Lixandrão et al.,
2014). CSA of the resulting EF and VL images
were then measured using computerized planimetry
(i.e. the VL and EF muscles CSA were contoured
following the muscle fascia using an 800 dpi
mouse) (Magic Mouse, Apple, USA) in two differ-
ent days, 72 h apart (intra-researcher reproducibil-
ity). The planimetry software was calibrated with
fixed distance scales displayed in the ultrasound
images. Testretest reliability of CSA measurements
using intra-class correlation coefficient (ICC),
typical error (TE), and coefficient of variation
(CV) for EF were 0.99, 0.43 cm
2
, and 3.2% and
for vastus lateralis were 0.99, 0.59 cm
2
, and 2.5%,
respectively.
Maximal dynamic strength (1RM)
Unilateral elbow flexor and unilateral leg press 45°
1RM testing were performed as per American
Society of Exercise Physiologists recommendations
(Brown & Weir, 2001). Briefly, participants ran for
5 min on a treadmill (Movement Technology;
Brudden) at 9 km h
1
, followed by two warm-up
sets of the unilateral EF exercise and unilateral leg
press 45°. In the first set, the participants performed
eight repetitions with an intensity corresponding to
50% of their estimated 1RM obtained during the
familiarization sessions. In the second set, they per-
formed three repetitions with 70% of their estimated
1RM. A 3-min rest interval was afforded between
warm-up sets. After the completion of the second
set, participants rested for 3 min and then had up to
five attempts to achieve their unilateral EF and unilat-
eral leg press 45° 1RM. A 3-min rest interval was
afforded between attempts (Brown & Weir, 2001).
An experienced researcher conducted all the tests,
and strong verbal encouragement was provided
during the test. Testretest reliability of 1RM
measurements using ICC, TE and CV for unilateral
EF were 0.99, 0.45 kg, and 1.86% and for unilateral
leg press 45° were 0.99, 4.77 kg, and 2.48%,
respectively.
Training programme
The RT was carried out twice per week for 12
weeks using unilateral elbow flexion and unilateral
leg press 45° exercises. The study employed a
within-subject design whereby one leg and arm
was set at 20% 1RM (G20, n= 30) for all partici-
pants and the contralateral limb was randomly
assigned to one of the three possible conditions:
40% 1RM (G40, n= 10); 60% 1RM (G60, n=
10), and 80% 1RM (G80, n= 10). The training pro-
tocol for G20 consisted of three sets of elbow
flexion and leg press exercise carried out to the
point of momentary concentric muscular failure
(i.e. the inability to perform another concentric
repetition while maintaining proper form). Total
VT performed by G20 was recorded and then
equatedinthecontralateral limb. In this case,
G40, G60, and G80 groups performed how
many sets and repetitions necessary to complete
the VT from G20, with repetitions performed
until to volitional failure and the training load
was adjusted every 4 weeks to ensure the target
intensity was achieved. The initial exercise per-
formed was altered in each session; in other
words, if one day, the subject started the session
with the unilateral elbow flexion, the other day,
he started with the unilateral leg press. All proto-
cols were performed with a 120-s rest period
between sets and cadence of repetitions was
carried out with a controlled concentric and
eccentric cycle of approximately 2-s each. Partici-
pants were instructed to refrain from performing
any additional resistance-type training throughout
the duration of the study.
Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy 3
Statistical analyses
Data were analysed quantitatively and visually to
verify normality (Shapiro-Wilk) and existence of out-
liers (box-plots). For measures of reproducibility,
testretest for CSA and 1RM employed the ICC,
absolute agreement, and TE which was calculated
as standard deviation of the difference between day
1 and day 2 measurements/2 and the CV which
was calculated as the (TE of the difference between
day 1 and day 2/means of the day 1 and day 2
values) × 100. A mixed model analysis was per-
formed for each dependent variable (CSA and
1RM), assuming the conditions (G20, G40, G60,
and G80) and time (pre, post-6 weeks and post-12
weeks) as fixed factors, and the participants as a
random factor. Whenever a significant F-value was
obtained, a post hoc test with a Tukeys adjustment
was performed for multiple comparison. ES was cal-
culated as the post-training mean minus the pre-
training mean divided by the pooled pre-training
standard deviation (Morris, 2008), where 0.2 =
small, 0.5 = medium, and 0.8 = large (Cohen,
1988). In addition, we presented the mean value
and confidence intervals from absolute difference
between groups (CIdiff). Positive and negative confi-
dence intervals that did not cross zero were con-
sidered significant. The significance level was set at
p< .05, and all analyses were made with statistical
software package SAS 9.2.
Results
No significant differences in any variables of interest
were observed between groups at baseline. The VT
for all groups was similar for unilateral elbow
flexion and unilateral leg press 45° exercises through-
out the study. The description of training variables is
depicted in Table I.
EF and VL cross-sectional area
There was significant main effect of time in EF and
VL CSA for all conditions following RT intervention
(p= .0001). EF CSA increased significantly in all
conditions from pre- to post-12 weeks (G20: 11.4%
ES: 0.63, G40: 25.3% ES: 2.10, G60: 25.1% ES:
1.40, and G80: 25% ES: 1.39). When the mean
value of differences between conditions were ana-
lysed at post-12 weeks, EF CSA in G80 was greater
than G20 (95%CI
diff
= 0.32 to 4.25, F= 3.74, d:
0.49, p= .01), but similar to G40 (95%CI
diff
=
1.66 to 3.15, F= 1.47, d: 0.78, p= .85) and G60
condition (95%CI
diff
=1.92 to 2.88, F= 1.47, d:
0.78, p= .95) (Figure 1).
For the VL CSA, all conditions showed significant
increases from pre- to post-12 weeks (p< .0001). VL
CSA increased significantly in all conditions from
pre- to post-12 weeks (G20: 8.9%, ES: 0.62; G40:
20.5%, ES: 1.16; G60: 20.4%, ES: 2.02; and G80:
19.5%, ES: 2.28). When mean value of differences
between conditions were analysed post-12 weeks,
VL CSA was greater in G80 than G20 (95%CI
diff
=
0.48 to 7.21, F= 3.09, d: 0.35, p= .01), but similar
to G40 (95%CI
diff
=2.97 to 5.27, F= 1.32, d:
1.55, p= .88) and G60 condition (95%CI
diff
=
2.71 to 5.53, F= 1.32, d: 1.59, p= .81) (Figure 2).
Maximal dynamic strength (1RM)
There was a significant time × condition interaction
for unilateral elbow flexion and unilateral leg press
45° 1RM (p= .0042). Unilateral elbow flexion 1RM
increased significantly from pre- to post-6 weeks in
the G20 (16.5%, ES: 0.93), G60 (30%, ES: 1.30),
and G80 (31.6%, ES: 1.96) conditions (F= 268.30,
p.05). In addition, unilateral elbow flexion 1RM
increased significantly from pre- to post-12 weeks
for all conditions (G20: 23.3%, ES: 1.25; G40:
26.7%, ES: 1.33; G60: 33.6%, ES: 1.41; and G80:
54.1%, ES: 4.56) (p< .0001). Elbow flexion 1RM
at post-12 weeks increase in G80 condition was sig-
nificantly higher when compared to G20 (95%CI
diff
= 2.35 to 10.98, F= 11.86, d: 1.49, p= .001), G40
(95%CI
diff
= 2.31 to 12.88, F= 11.86, d: 1.69, p
= .001), and G60 conditions (95%CI
diff
= 1.51 to
12.08, F= 11.86, d: 1.32, p= .001) (Table II).
Unilateral leg press 45° 1RM increased signifi-
cantly from pre- to post-6 weeks in G20 (15.8, ES:
0.75), G40 (27.9%, ES: 1.24), G60 (32.1%, ES:
1.42), and G80 (25.6%, ES: 1.42) conditions (F=
242.40; p< .0001). Additionally, unilateral leg press
45° 1RM increased significantly from pre- to post-
12 weeks for all conditions (G20: 22.1% ES: 1.14;
G40: 30.4%, ES: 1.43; G60: 55.4%, ES: 2.99; and
G80: 45.7%, ES: 3.27) (p< .0001). Finally, leg
press 45° 1RM increases at post-12 weeks in the
G60 and G80 conditions were significantly higher
when compared to G20 and G40 (G60 vs. G20:
95%CI
diff
=0.65 to 73.66, F= 10.82, d: 1.00, p
= .04; G80 vs. G20: 95%CI
diff
= 3.34 to 77.66, F=
10.82, d: 1.11, p< .05; G60 vs. G40: 95%CI
diff
=
4.37 to 3.87, F= 10.82, d: 1.59, p= .02; and G80
vs. G40: 95%CI
diff
= 8.49 to 99.51, F= 10.82, d:
1.74, p< .05) (Table II).
Discussion
The present study investigated the effects of different
intensities of RT (2080% 1RM) with equated
4T. Lasevicius et al.
volume on muscular strength and hypertrophy fol-
lowing 12 weeks of regimented training. Our main
findings were: (a) all intensities of RT increased the
EF and VL CSA; (b) all intensities of RT increased
elbow flexion and leg press 1RM. The magnitude of
increases in muscle CSA and 1RM of the upper
and lower body when training at 80% 1RM were
greater than at 20% 1RM.
The findings of this study call into question the
American College of Sports Medicine guidelines
stating that the use of loads 65% 1RM are required
to promote hypertrophic adaptations (American
College of Sports Medicine, 2009). Alternatively,
our findings corroborate the results from other
studies that demonstrated low-intensity RT per-
formed until volitional failure can increase muscle
mass to a similar extent as high-intensity RT at least
with loads 40% 1RM, even when volume is
equated between conditions (Mitchell et al., 2012;
Ogasawara et al., 2013; Schoenfeld et al., 2015).
Some researchers have proposed that it is necessary
to perform a higher volume of low-intensity training
to achieve the magnitude of increase in muscle size
observed with high-intensity training (Burd et al.,
2010; Burd, Mitchell, Churchward-Venne, & Phil-
lips, 2012; Mitchell et al., 2012). In general, a
majority of studies that investigated the topic
employed a substantially higher training volume for
the low-intensity condition (Mitchell et al., 2012;
Ogasawara et al., 2013; Schoenfeld et al., 2015),
which conceivably could have affected the hyper-
trophic response.
Ours is the first study to match the VT between a
wide range of intensities (e.g. 2080% 1RM) based
on VT in the lowest intensity condition. This strategy
was adopted in order to avoid potentially misleading
interpretations when the VT between training proto-
cols are different and thus isolate the effects of inten-
sity on muscular adaptations. For example, the VT
performed in other studies that use low-intensity
RT (30% 1RM) was higher than those shown with
high-intensity RT (80% 1RM) (Mitchell et al.,
2012; Ogasawara et al., 2013; Schoenfeld et al.,
2015). It is possible that muscle hypertrophy in the
heavier intensity conditions in these studies may
have been blunted by the lower amount of volume
performed compared to the lighter-intensity con-
ditions. However, our study indicates that volume
was not a significant factor in this regard, at least
with respect to intensities of 40% 1RM. This
suggests that there is a threshold of volume needed
to promote marked increases in muscle hypertrophy
with intensities between 40% and 80% 1RM.
Although upper and lower body CSA were
increased in all conditions, the highest intensity con-
dition (80% 1RM) presented greater gains compared
with the lightest intensity condition (20% 1RM).
Consistent with these findings, data from Holm
et al. (2008) found a higher increase in quadriceps
CSA when training at 70% vs. 15.5% 1RM with the
VT equated between the conditions. However, sub-
jects in the study did not train to failure in the low-
intensity condition, confounding the ability to draw
causality on the hypertrophic effects of the different
loading schemes. Our findings suggest that there is
a minimum intensity necessary to trigger important
mechanisms involved in increasing muscle size
(Holm et al., 2008; Kumar et al., 2009), and it
appears that 20% 1RM falls below this threshold.
Given that we did not study intensities between
20% and 40% 1RM, it is not clear where the
minimum threshold lies along this continuum.
Hypertrophy-oriented routines are often designed
to raise mechanical tension and/or metabolic stress
(Goto, Ishii, Kizuka, & Takamatsu, 2005; Schoen-
feld, 2010; Seynnes, de Boer, & Narici, 2007).
Given that the increase in CSA in this study was
similar between intensities of 40% and 80%, it can
be inferred that protocols designed to maximize
metabolic stress (i.e. high number of repetitions and
low to moderate intensities) and protocols designed
to maximize mechanical tension (low number of
Table I. Training variables for the unilateral elbow flexion and unilateral leg press 45° exercises.
Unilateral elbow flexion
Training variables G20 G40 G60 G80
Sets 3 ± 0 3.7 ± 1 4.5 ± 1.2 4.2 ± 1
Repetitions 67.7 ± 18.728.2 ± 10.5∗∗ 14.5 ± 4.7 10.2 ± 2.8
Volume load 21,674.1 ± 2952.7 21,919.1 ± 3028.1 20,822 ± 3644.1 20,543 ± 3479.5
Unilateral leg press 45°
Training variables G20 G40 G60 G80
Sets 3 ± 0 2.5 ± 0.4 3.4 ± 1.4 3.1 ± 0.9
Repetitions 61.1 ± 29.930.8 ± 8.0 18.8 ± 5.9 14.0 ± 4.6
Volume load 163,043.0 ± 34,695.2 153,946.2 ± 28,285.5 160,900 ± 30,997.9 169,095.4 ± 36,054.5
Significant difference from G40, G60 and G80 (p< .05).
∗∗Significant difference from G80 (p< .05).
Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy 5
repetitions and high intensities) would promote
similar hypertrophic increases when the VT is
matched. Thus, these findings suggest that VT
plays an important role in increasing muscle mass
as opposed to inherent aspects of the protocol itself
or training stimulus.
There were significant increases in strength for all
groups following 6 and 12 weeks of RT. The
increases in strength levels in the initial weeks of
training have been attributed to neural mechanisms
(Gabriel, Kamen, & Frost, 2006; Sale, 1988), and
this appears to be the case even with the very low-
intensity condition (20% 1RM) employed in our
study. Holm et al. (2008) found that an intensity of
15.5% 1RM was insufficient for increasing muscle
strength following regimented RT. However, as pre-
viously mentioned, the sets in this condition were not
taken to muscular failure. In contrast to the findings
by Holm et al. (2008), our results showed G20
increased 1RM in the arm curl and leg press through-
out the training period. Discrepancies in results may
in part be attributable to differences in the manipu-
lation of total training volume in combination with
the level of effort expended (i.e. proximity to
failure) in the low-intensity condition. Specifically,
the total VT for all groups in our study was based
on G20 and all the volume of all other conditions
(G40, G60, and G80) was matched to the volume
load achieved in G20, with repetitions performed
until to volitional failure.
One interesting aspect of our findings is that
strength appeared to plateau after 6 weeks in the
lower intensity conditions and, after 12 weeks,
higher training intensities resulted in greater strength
increases compared to lower intensities. These results
are in agreement with previous studies on the topic
that demonstrated an advantage for higher intensities
on muscle strength performance (Campos et al.,
Figure 1. Elbow flexor CSA values from pre-test to post-6 weeks and post-12 weeks for G20, G40, G60, and G80 conditions (mean ± SD).
Significant difference from pre-test (p< .05).
#
Significantly greater than G20 group at post-12 weeks (p< .05).
Figure 2. VL CSA values from pre-test to post-6 weeks and post-12 weeks for G20, G40, G60, and G80 conditions (mean ± SD). Significant
difference from pre-test (p< .05).
#
Significantly greater than G20 group at post-12 weeks (p< .05).
6T. Lasevicius et al.
2002; Mitchell et al., 2012; Ogasawara et al., 2013;
Schoenfeld et al., 2015). Untrained individuals parti-
cipating in the initial stages of RT generally have a
low level of fitness and lack the coordination to
perform exercises in a fluid manner. Thus, all
loading schemes provided a sufficient stimulus to
produce increases in muscular strength (Harris,
Debeliso, Spitzer-gibson, & Adams, 2004).
However, it can be speculated that over time
heavier intensities are necessary to continue making
gains. This is consistent with evidence that resist-
ance-trained individuals require higher intensities to
improve muscle strength (Peterson, Rhea, & Alvar,
2004; Rhea, Alvar, Burkett, & Ball, 2003).
Although we did not attempt to elucidate the
mechanisms responsible for our findings, it seems
plausible that neural adaptations may explain the
different strength responses between intensities.
Specifically, high-intensity RT may promote greater
effects on motor unit recruitment, motor unit firing
rates, and/or alterations in agonist-antagonist co-acti-
vation ratios compared to training at lower intensities
(Gabriel et al., 2006; Sale, 1988). Alternatively, other
factors related to the principle of specificity may be
involved in the process, whereby high-intensity train-
ing has greater similarities to 1RM testing versus low-
intensity training (Aagaard, Simonsen, Trolle,
Bangsbo, & Klausen, 1996; Cronin, McNair, & Mar-
shall, 2001). Further research is needed to determine
mechanistic explanations.
The present study is not without limitations. First,
the study was performed in young men with no pre-
vious experience in RT. Thus, our findings cannot
be generalized to other population including
women, elderly, and/or resistance-trained individ-
uals. Second, it is possible that differences in training
status, hormonal influence, and other factors could
influence muscular adaptations when training at
different intensities. Third, we cannot rule out the
possibility that the cross-education effect may have
influenced strength results given the within-subject
design. However, the fact that the highest intensity
condition showed the greatest changes in strength
indicates that any influence of cross-education, if
such a phenomenon did in fact occur, was not suffi-
cient to counteract the effects of heavier loading on
this outcome. Lastly, we did not attempt to deter-
mine nutritional intake, which may have influenced
results between conditions. However, the within-
subject design would have helped to minimize any
potential variations attributed to this variable.
In conclusion, our results demonstrated that inten-
sities ranging from 20% to 80% 1RM are effective for
increasing muscle strength and hypertrophy in men
with no experience in RT. However, our findings
indicate that the lowest RT intensity (20% 1RM)
was suboptimal for maximizing muscular adap-
tations. With regards to strength gains, our results
indicate that over the initial 6 weeks of training all
the studied intensities can produce increases in
1RM. However, if maximizing strength gains over
the long-term training is a primary goal, it is necessary
employ higher training intensities.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
Hamilton Roschel http://orcid.org/0000-0002-9513-
6132
Lucas Duarte Tavares http://orcid.org/0000-0003-
0941-6224
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Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy 9
... After 12 weeks, elbow flexion 1RM and muscle CSA increase in G80 condition was significantly higher than those in G20, G40, and G60 conditions. 105 There was no significant difference in the increase in unilateral leg press strength between G60 and G80, but they both displayed more obvious effect than G20 and G40. 105 Seynnes et al found that while both high intensity (HI) (80% 1RM) and low intensity (LI) training (40% 1RM) significantly improved muscle strength and endurance of frail elders compared with the control, high intensity training group elicited significantly better outcomes than low intensity training group. ...
... 105 There was no significant difference in the increase in unilateral leg press strength between G60 and G80, but they both displayed more obvious effect than G20 and G40. 105 Seynnes et al found that while both high intensity (HI) (80% 1RM) and low intensity (LI) training (40% 1RM) significantly improved muscle strength and endurance of frail elders compared with the control, high intensity training group elicited significantly better outcomes than low intensity training group. 106 A similar phenomenon was observed by other scientists. ...
... 109 However, when it comes to the gains in muscle mass, low to moderate intensities (30-50% 1RM) have a similar or even greater effect compared with high intensities. 105 Above all, all the low to high intensities training enhances muscle strength and muscle mass of the elderly, but high intensities displayed greater effect than low-intensity to moderate intensity on increasing strength without causing higher risks. ...
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... Muscle hypertrophy adaptations induced by resistance training have been shown to be similar using high (> 60% of 1RM) or low (≤ 60% of 1RM) loads, but strength gains are greater training with high loads (Schoenfeld et al. 2017b;Lasevicius et al. 2018). In this sense, performing 3 set of leg extension to failure with 2 min of inter-set rest at 80% of 1RM during 6 weeks (3 times per week) has demonstrated to be more effective to increase 1RM and MVIC than performing the same training at 30% 1RM, while muscle thickness increased similarly in both groups (Jenkins et al. 2017). ...
... In fact, although low loads (i.e., ≤ 60% of 1RM) provoke higher levels of metabolic stress, they do not lead more muscle hypertrophy than higher loads (i.e., > 60% of 1RM) (Schoenfeld et al. 2017b). A recent study showed that when volume load was equated and sets were performed to failure, training at 40%, 60%, or 80% of 1RM was effective for maximizing muscle hypertrophy but not training at 20% of 1RM (Lasevicius et al. 2018). Besides, another recent study equating volume load reported no differences in the volume of pectoralis major muscle measured by 3 T magnetic resonance imaging after training bench press at 4RM, 8RM, or 12RM during 10 weeks (2 days per week) (Kubo et al. 2021). ...
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... Future research should be done to assess this hypothesis and determine if training status influences the effect of different intensities on such adaptations. As displayed in ▶ Fig. 2 it is now known that hypertrophy occurs along a wide spectrum of intensities (30-90 % of 1-RM) and corresponding rep-ranges (3-35 reps per set) [3,14,15,78,79]. Assuming a traditional 2:1 second repetition tempo, this effective repetition range corresponds with 9-105 seconds of TUT per set. ...
... The specificity of RT was best exemplified by Campos et al. [95] who reported that improvements in muscular endurance were greatest in the high-repetition group (2 sets; 20-28 reps), increases in muscular strength were greatest in the low-repetition group (4 sets; 3-5 reps), and hypertrophy only occurred in the low and intermediate-repetition groups (3 sets; 9-11 reps) [95]. Although their conclusions suggested that RT adaptations were largely specific to intensity, more recent evidence suggests that improvements for hypertrophy, strength, and power occur along a spectrum of 20-80 % of 1-RM [78,79]. Moreover, Schoenfeld (14), in a recent meta-analysis concluded that low ( < 60 % 1-RM) and high ( > 65 % 1-RM) intensity RT have similar and positive effects on muscular strength (9 studies, n = 251) and hypertrophy (8 studies, n = 191). ...
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... la capacidad de aplicar fuerza y/o aplicarla con calidad. Es por ello que a mayor duración del ejercicio y tempo, mayor fatiga central ante la misma intensidad relativa ya sea controlando exageradamente el tempo, o trabajando en un rango de repeticiones muy altos (25<), lo que se podría traducir en menos hipertrofia como tal y mayor fatiga central (Lasevicius et. al, 2018), lo que repercutirá en el rendimiento de la sesión, y aunque dependerá del ejercicio, pues en el caso del estudio de Pereira y cols. (2016) compararon los tempos bajo el ejercicio de curl de bíceps en banco Scott, al ser este un ejercicio mono articular y de menor complejidad técnica, la fatiga producida no sería mayormente relevante (R ...
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The duration of the repetition (tempo) refers to the total time that a single repetition lasts within a set, being the result of the sum between the concentric, isometric and eccentric phase of the lift. There is controversy regarding the duration of the repetition (and its phases) and its impact on muscle hypertrophy. The objective of this review was to analyze the effects of training programs using different lifting tempos and their impact on hypertrophy. METHODOLOGY. A literature search was carried out in the Pubmed electronic database, with the following inclusion criteria: i) training programs that induce volitional failure, ii) studies had been carried out under dynamic actions and with ≥4 weeks of intervention, and iii) the study included participants >18 years of age. RESULTS. From 473 studies, 4 were included, including 79 men and 34 women, and the tempos varied between 1.5 and 90 seconds, with lower tempos associated with greater hypertrophic effect. CONCLUSION. Tempos between 2 and 6 seconds seems effective in inducing hypertrophic adaptations.
... It is unclear if training to volitional muscular failure with BFRT is required to derive adaptations, with previous BFRT studies suggesting it may be unnecessary . Previous studies have shown that muscular failure is not required for muscle hypertrophy, with overall training load volume considered more relevant for augmenting hypertrophy (Schoenfeld et al., 2017Lasevicius et al., 2018Lasevicius et al., , 2019. Details on rest periods and whether cuff pressure was maintained or deflated between sets and exercises varied across studies. ...
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Objective: To identify current evidence on blood flow restriction training (BFRT) in tendon injuries and healthy tendons, evaluating physiological tendon effects, intervention parameters and outcomes. Methods: This scoping review was reported in accordance with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Databases searched included MEDLINE, CINAHL, AMED, EMBase, SPORTDiscus, Cochrane library (Controlled trials, Systematic reviews), and five trial registries. Two independent reviewers screened studies at title/abstract and full text. Following screening, data was extracted and charted, and presented as figures and tables alongside a narrative synthesis. Any study design conducted on adults, investigating the effects of BFRT on healthy tendons or tendon pathology were included. Data were extracted on physiological tendon effects, and intervention parameters and outcomes with BFRT. Results: 13 studies were included, 3 on tendinopathy, 2 on tendon ruptures and 8 on healthy Achilles, patellar, supraspinatus and vastus lateralis tendons. A variety of outcomes were assessed, including pain, function, strength, and tendon morphological and mechanical properties, particularly changes in tendon thickness. BFRT intervention parameters were heterogeneously prescribed. Conclusion: Despite a dearth of studies to date on the effects of BFRT on healthy tendons and in tendon pathologies, preliminary evidence for beneficial effects of BFRT on tendons and clinical outcomes is encouraging. As BFRT is a relatively novel method, definitive conclusions, and recommendations on BFRT in tendon rehabilitation cannot be made at present, which should be addressed in future research, due to the potential therapeutic benefits highlighted in this review.
... Translated to a percentage of 1-RM (Shimano et al., 2006), the low, intermediate, and high repetition groups trained at an intensity of approximately >90, 80, and <60% 1-RM, respectively. More recent evidence suggested, however, that muscle hypertrophy can be achieved in untrained subjects with an exercise intensity as low as 20% of 1-RM when performing the exercise until failure (Lasevicius et al., 2018). At intensities of 40% and higher, relative improvement in muscle CSA was almost numerically equal, ranging between 19.5 and 20.5%. ...
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Purpose: The aim of this study was to compare the effects of moderate intensity, low volume (MILV) vs. low intensity, high volume (LIHV) strength training on sport-specific performance, measures of muscular fitness, and skeletal muscle mass in young kayakers and canoeists. Methods: Semi-elite young kayakers and canoeists (N = 40, 13 ± 0.8 years, 11 girls) performed either MILV (70–80% 1-RM, 6–12 repetitions per set) or LIHV (30–40% 1-RM, 60–120 repetitions per set) strength training for one season. Linear mixed-effects models were used to compare effects of training condition on changes over time in 250 and 2,000 m time trials, handgrip strength, underhand shot throw, average bench pull power over 2 min, and skeletal muscle mass. Both between- and within-subject designs were used for analysis. An alpha of 0.05 was used to determine statistical significance. Results: Between- and within-subject analyses showed that monthly changes were greater in LIHV vs. MILV for the 2,000 m time trial (between: 9.16 s, SE = 2.70, p < 0.01; within: 2,000 m: 13.90 s, SE = 5.02, p = 0.01) and bench pull average power (between: 0.021 W⋅kg–1, SE = 0.008, p = 0.02; within: 0.010 W⋅kg–1, SE = 0.009, p > 0.05). Training conditions did not affect other outcomes. Conclusion: Young sprint kayakers and canoeists benefit from LIHV more than MILV strength training in terms of 2,000 m performance and muscular endurance (i.e., 2 min bench pull power).
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Background: Previous reviews indicated positive effects of resistance training (RT) on motor outcomes in Parkinson's disease (PD). However, inconsistencies between the included studies exist, and non-motor outcomes have only scarcely been considered in a review on RT in PD. Objective: To analyze the RT effects on motor- and non-motor outcomes in PD patients compared to passive and physically active control groups (i.e., other structured physical interventions). Methods: We searched CENTRAL, MEDLINE, EMBASE, and CINAHL for randomized controlled trials of RT in PD. After identifying 18 studies, a meta-analysis was conducted for the outcomes muscle strength, motor impairment, freezing of gait (FoG), mobility and balance, quality of life (QoL), depression, cognition, and adverse events. Meta-analyses with random models were calculated using mean differences (MD) or standardized mean differences (SMD) with 95% confidence intervals (CI). Results: When comparing RT with passive control groups, the meta-analyses showed significant large effects on muscle strength (SMD = -0.84, 95% CI -1.29--0.39, p = 0.0003), motor impairment (SMD = -0.81, 95% CI -1.34--0.27, p = 0.003), mobility and balance (MD = -1.81, 95% CI -3.13--0.49, p = 0.007), and small significant effects on QoL (SMD = -0.48, 95% CI -0.86--0.10, p = 0.01). RT compared with physically active control groups reached no significant results for any outcome. Conclusions: RT improves muscle strength, motor impairment, mobility and balance, QoL, and depression in PD patients. However, it is not superior to other physically active interventions. Therefore, exercise is important for PD patients but according to this analysis, its type is of secondary interest.
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Tendinopathy is chronic tendon disease which can cause significant pain and functional limitations for individuals and collectively place a tremendous burden on society. Resistance training has long been considered the treatment of choice in the rehabilitation of chronic tendinopathies, with both eccentric and heavy slow resistance training demonstrating positive clinical effects. The application of progressive tendon loads during rehabilitation is essential to not compromise tendon healing, with the precise dosing parameters of resistance training and external loading a critical consideration. Blood-flow restriction training (BFRT) has become an increasingly popular method of resistance training in recent years and has been shown to be an effective method for enhancing muscle strength and hypertrophy in healthy populations and in musculoskeletal rehabilitation. Traditional resistance training for tendinopathy requires the application of heavy training loads, whereas BFRT utilises significantly lower loads and training intensities, which may be more appropriate for certain clinical populations. Despite evidence confirming the positive muscular adaptations derived from BFRT and the clinical benefits found for other musculoskeletal conditions, BFRT has received a dearth of attention in tendon rehabilitation. Therefore, the purpose of this narrative review was threefold: firstly, to give an overview and analysis of the mechanisms and outcomes of BFRT in both healthy populations and in musculoskeletal rehabilitation. Secondly, to give an overview of the evidence to date on the effects of BFRT on healthy tendon properties and clinical outcomes when applied to tendon pathology. Finally, a discussion on the clinical utility of BFRT and its potential applications within tendinopathy rehabilitation, including as a compliment to traditional heavy-load training, will be presented.
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The purpose of this paper was to conduct a systematic review of the current body of literature and a meta-analysis to compare changes in strength and hypertrophy between low- versus high-load resistance training protocols. Searches of PubMed/MEDLINE, Cochrane Library and Scopus were conducted for studies that met the following criteria: 1) an experimental trial involving both low- (≤60% 1 RM) and high- (>60% 1 RM) load training; 2) with all sets in the training protocols being performed to momentary muscular failure; 3) at least one method of estimating changes in muscle mass and/or dynamic, isometric or isokinetic strength was used; 4) the training protocol lasted for a minimum of 6 weeks; 5) the study involved participants with no known medical conditions or injuries impairing training capacity. A total of 21 studies were ultimately included for analysis. Gains in 1RM strength were significantly greater in favor of high- versus low-load training, while no significant differences were found for isometric strength between conditions. Changes in measures of muscle hypertrophy were similar between conditions. The findings indicate that maximal strength benefits are obtained from the use of heavy loads while muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
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The purpose of this paper was to systematically review the current literature and elucidate the effects of total weekly resistance training (RT) volume on changes in measures of muscle mass via meta-regression. The final analysis comprised 34 treatment groups from 15 studies. Outcomes for weekly sets as a continuous variable showed a significant effect of volume on changes in muscle size (P = 0.002). Each additional set was associated with an increase in effect size (ES) of 0.023 corresponding to an increase in the percentage gain by 0.37%. Outcomes for weekly sets categorised as lower or higher within each study showed a significant effect of volume on changes in muscle size (P = 0.03); the ES difference between higher and lower volumes was 0.241, which equated to a percentage gain difference of 3.9%. Outcomes for weekly sets as a three-level categorical variable (<5, 5-9 and 10+ per muscle) showed a trend for an effect of weekly sets (P = 0.074). The findings indicate a graded dose-response relationship whereby increases in RT volume produce greater gains in muscle hypertrophy.
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American College of Sports Medicine Position Stand on Progression Models in Resistance Training for Healthy Adults. Med. Sci. Sports Exerc. Vol. 34, No. 2, 2002, pp. 364-380. In order to stimulate further adaptation toward a specific training goal(s), progression in the type of resistance training protocol used is necessary. The optimal characteristics of strength-specific programs include the use of both concentric and eccentric muscle actions and the performance of both single- and multiple-joint exercises. It is also recommended that the strength program sequence exercises to optimize the quality of the exercise intensity (large before small muscle group exercises, multiple-joint exercises before single-joint exercises, and higher intensity before lower intensity exercises). For initial resistances, it is recommended that loads corresponding to 8-12 repetition maximum (RM) be used in novice training. For intermediate to advanced training, it is recommended that individuals use a wider loading range, from 1-12 RM in a periodized fashion, with eventual emphasis on heavy loading (1-6 RM) using at least 3-min rest periods between sets performed at a moderate contraction velocity (1-2 s concentric. 1-2 s eccentric). When training at a specific RM load, it is recommended that 2-10% increase in load be applied when the individual can perform the current workload for one to two repetitions over the desired number. The recommendation for training frequency is 2-3 d.wk(-1) for novice and intermediate training and 4-5 d.wk(-1) for advanced training. Similar program designs are recommended for hypertrophy training with respect to exercise selection and frequency. For loading, it is recommended that loads corresponding to 1-12 RM be used in periodized fashion, with emphasis on the 6-12 RM zone using 1- to 2-min rest periods between sets at a moderate velocity. Higher volume, multiple-set programs are recommended for maximizing hypertrophy. Progression in power training entails two general loading strategies: 1) strength training, and 2) use of light loads (30-60% of 1 RM) performed at a fast contraction velocity with 2-3 min of rest between sets for multiple sets per exercise. It is also recommended that emphasis be placed on multiple-joint exercises, especially those involving the total body. For local muscular endurance training, it is recommended that light to moderate loads (40-60% of 1 RM) be performed for high repetitions (> 15) using short rest periods (< 90 s). In the interpretation of this position stand, as with prior ones, the recommendations should be viewed in context of the individual's target goals, physical capacity, and training status.
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It is generally accepted that neural factors play an important role in muscle strength gains. This article reviews the neural adaptations in strength, with the goal of laying the foundations for practical applications in sports medicine and rehabilitation. An increase in muscular strength without noticeable hypertrophy is the first line of evidence for neural involvement in acquisition of muscular strength. The use of surface electromyographic (SEMG) techniques reveal that strength gains in the early phase of a training regimen are associated with an increase in the amplitude of SEMG activity. This has been interpreted as an increase in neural drive, which denotes the magnitude of efferent neural output from the CNS to active muscle fibres. However, SEMG activity is a global measure of muscle activity. Underlying alterations in SEMG activity are changes in motor unit firing patterns as measured by indwelling (wire or needle) electrodes. Some studies have reported a transient increase in motor unit firing rate. Training-related increases in the rate of tension development have also been linked with an increased probability of doublet firing in individual motor units. A doublet is a very short interspike interval in a motor unit train, and usually occurs at the onset of a muscular contraction. Motor unit synchronisation is another possible mechanism for increases in muscle strength, but has yet to be definitely demonstrated. There are several lines of evidence for central control of training-related adaptation to resistive exercise. Mental practice using imagined contractions has been shown to increase the excitability of the cortical areas involved in movement and motion planning. However, training using imagined contractions is unlikely to be as effective as physical training, and it may be more applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a strong practice effect. Bilateral contractions are associated with lower SEMG and strength compared with unilateral contractions of the same muscle group. SEMG magnitude is lower for eccentric contractions than for concentric contractions. However, resistive training can reverse these trends. The last line of evidence presented involves the notion that unilateral resistive exercise of a specific limb will also result in training effects in the unexercised contralateral limb (cross-transfer or cross-education). Peripheral involvement in training-related strength increases is much more uncertain. Changes in the sensory receptors (i.e. Golgi tendon organs) may lead to disinhibition and an increased expression of muscular force. Agonist muscle activity results in limb movement in the desired direction, while antagonist activity opposes that motion. Both decreases and increases in co-activation of the antagonist have been demonstrated. A reduction in antagonist co-activation would allow increased expression of agonist muscle force, while an increase in antagonist co-activation is important for maintaining the integrity of the joint. Thus far, it is not clear what the CNS will optimise: force production or joint integrity. The following recommendations are made by the authors based on the existing literature. Motor learning theory and imagined contractions should be incorporated into strength-training practice. Static contractions at greater muscle lengths will transfer across more joint angles. Submaximal eccentric contractions should be used when there are issues of muscle pain, detraining or limb immobilisation. The reversal of antagonists (antagonist-to-agonist) proprioceptive neuromuscular facilitation contraction pattern would be useful to increase the rate of tension development in older adults, thus serving as an important prophylactic in preventing falls. When evaluating the neural changes induced by strength training using EMG recording, antagonist EMG activity should always be measured and evaluated.
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The purpose of this study was to compare the effect of low- versus high-load resistance training (RT) on muscular adaptations in well-trained subjects. Eighteen young men experienced in RT were matched according to baseline strength, and then randomly assigned to 1 of 2 experimental groups: a low-load RT routine (LL) where 25-35 repetitions were performed per set per exercise (n = 9), or a high-load RT routine (HL) where 8-12 repetitions were performed per set per exercise (n = 9). During each session, subjects in both groups performed 3 sets of 7 different exercises representing all major muscles. Training was carried out 3 times per week on non-consecutive days, for 8 total weeks. Both HL and LL conditions produced significant increases in thickness of the elbow flexors (5.3 vs. 8.6%, respectively), elbow extensors (6.0 vs. 5.2%, respectively), and quadriceps femoris (9.3 vs. 9.5%, respectively), with no significant differences noted between groups. Improvements in back squat strength were significantly greater for HL compared to LL (19.6 vs. 8.8%, respectively) and there was a trend for greater increases in 1RM bench press (6.5 vs. 2.0%, respectively). Upper body muscle endurance (assessed by the bench press at 50% 1RM to failure) improved to a greater extent in LL compared to HL (16.6% vs. -1.2%, respectively). These findings indicate that both HL and LL training to failure can elicit significant increases in muscle hypertrophy among well-trained young men; however, HL training is superior for maximizing strength adaptations.
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Background The beneficial effects of cardiorespiratory fitness on mortality are well known; however, the relation of muscular fitness, specifically muscular strength and endurance, to mortality risk has not been thoroughly examined. The purpose of the current study is to determine if a dose-response relation exists between muscular fitness and mortality after controlling for factors such as age and cardiorespiratory fitness. Methods The study included 9105 men and women, 20–82 years of age, in the Aerobics Center Longitudinal Study who have completed at least one medical examination at the Cooper Clinic in Dallas, TX between 1981 and 1989. The exam included a muscular fitness assessment, based on 1-min sit-up and 1-repetition maximal leg and bench press scores, and a maximal treadmill test. We conducted mortality follow-up through 1996 primarily using the National Death Index, with a total follow-up of 106,046 person-years. All-cause mortality rates were examined across low, moderate, and high muscular fitness strata. Results Mortality was confirmed in 194 of 9105 participants (2.1%). The age- and sex-adjusted mortality rate of those in the lowest muscular fitness category was higher than that of those in the moderate fitness category (26.8 vs. 15.3 per 10,000 person-years, respectively). Those in the high fitness category had a mortality rate of 20.6 per 10,000 person-years. The moderate and high muscular fitness groups had relative risks of 0.64 (95%CI = 0.44–0.93) and 0.80 (95%CI = 0.49–1.31), adjusting for age, health status, body mass index, cigarette smoking, and cardio-respiratory fitness when compared with the low muscular fitness group. Conclusions Mortality rates were lower for individuals with moderate/high muscular fitness compared to individuals with low muscular fitness. These findings warrant further research to confirm the apparent threshold effect between low and moderate/high muscular fitness and all-cause mortality.
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Purpose It has been hypothesized that lifting light loads to muscular failure will activate the full spectrum of MUs and thus bring about muscular adaptations similar to high-load training. The purpose of this study was to investigate EMG activity during low- versus high-load training during performance of a multi-joint exercise by well-trained subjects. Methods Employing a within-subject design, 10 young, resistance-trained men performed sets of the leg press at different intensities of load: a high-load (HL) set at 75 % of 1-RM and a low-load (LL) set at 30 % of 1-RM. The order of performance of the exercises was counterbalanced between participants, so that half of the subjects performed LL first and the other half performed HL first, separated by 15 min rest. Surface electromyography (EMG) was used to assess mean and peak muscle activation of the vastus medialis, vastus lateralis, rectus femoris, and biceps femoris. Results Significant main effects for trials and muscles were found (p
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In this study, the difference between the effects of "power-up type" and "bulk-up type" strength training exercise was investigated by analyzing parameters such as structural and functional adaptations in the neuromuscular system. Eleven subjects were divided into power-up and bulk-up groups. The power-up group comprised five male subjects who performed 5 sets at 90% of one repetition maximum (1 RM) with a 3-min rest between sets (repetition method). The bulk-up group comprised six male subjects who performed 9 sets at 80-60-50%, 70-50-40%, and 60-50-40% of 1 RM with rest intervals between sets of either 30 s or 3 min (interval method). Both groups performed isotonic knee extension exercise twice a week for 8 weeks. The power-up group showed a lower rate of improvement than the bulk-up group in terms of cross-sectional area (CSA) of the quadriceps femoris at levels 30% , 50% and 70% from the top of the femur, and also in average isokinetic strength (Isok. ave.; 180 deg/s, 50 consecutive repetitions). However, the power-up group showed a greater rate of improvement in 1 RM, maximal isometric strength (Isom. max), and maximal isokinetic strength (Isok. max ; 60, 180, 300 deg/s). Furthermore, the rate of reduction in strength over 50 consecutive isokinetic repetitions decreased in the bulk-up group. On the other hand, the power-up group showed no significant changes in the above throughout the entire training program. These results indicate that the characteristics of the two types of training exercise are as follows:(1) power-up exercise is effective mainly for improving muscular strength and anaerobic power, and (2) bulk-up exercise is effective mainly for improving hypertrophy and anaerobic endurance. These findings support the idea that "power-up type" and "bulk-up type" strength training exercises should be applied appropriately according to the training aim.