Journal of Sports Sciences

ISSN: 0264-0414 (Print) 1466-447X (Online) Journal homepage: http://www.tandfonline.com/loi/rjsp20

Bar velocities capable of optimising the muscle

power in strength-power exercises

Irineu Loturco, Lucas Adriano Pereira, Cesar Cavinato Cal Abad, Facundo
Tabares, José Eduardo Moraes, Ronaldo Kobal, Katia Kitamura & Fabio Yuzo
Nakamura

To cite this article: Irineu Loturco, Lucas Adriano Pereira, Cesar Cavinato Cal Abad, Facundo
Tabares, José Eduardo Moraes, Ronaldo Kobal, Katia Kitamura & Fabio Yuzo Nakamura (2016):
Bar velocities capable of optimising the muscle power in strength-power exercises, Journal of
Sports Sciences, DOI: 10.1080/02640414.2016.1186813

To link to this article: http://dx.doi.org/10.1080/02640414.2016.1186813

Published online: 21 May 2016.

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 JOURNAL OF SPORTS SCIENCES, 2016
http://dx.doi.org/10.1080/02640414.2016.1186813

Bar velocities capable of optimising the muscle power in strength-power exercises

Irineu Loturcoa, Lucas Adriano Pereiraa, Cesar Cavinato Cal Abada, Facundo Tabaresb, José Eduardo Moraesb,
Ronaldo Kobala, Katia Kitamuraa,b and Fabio Yuzo Nakamuraa,c
a
NAR - Nucleus of High Performance in Sport, São Paulo, Brazil; bBrazilian Rugby Confederation, São Paulo, Brazil; cDepartment of Physical
Education, State University of Londrina, Londrina, Brazil

ABSTRACT ARTICLE HISTORY

This study aimed at testing whether there are mean propulsive velocities (MPVs) capable of maximising Accepted 3 May 2016
the mean propulsive power (MPP) during the execution of bench press (BP), bench throw (BT), half
KEYWORDS
squat (HS) and jump squat (JS). Additionally, we assessed the differences in MPP/MPV between ballistic Optimal loads; plyometrics;
and traditional exercises. Seventeen male rugby sevens players performed MPP tests in BP, BT, HS and power training; sports
JS and maximum isometric force (MIF) tests in HS and BP. The JS presented higher MPP performance; team sports
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(977.4 ± 156.2 W) than the HS (897.9 ± 157.7 W) (P < 0.05); the BP (743.4 ± 100.1 W) presented higher
MPP than the BT (697.8 ± 70.4 W) (P < 0.05). Ballistic exercises presented higher optimum MPV
(JS = 1.02 ± 0.07 m·s−1; BT = 1.67 ± 0.15 m·s−1) than traditional exercises (HS = 0.93 ± 0.08 m·s−1;
BP = 1.40 ± 0.13 m·s−1) (P < 0.05). The optimum MPP in the JS, BT, HS and BP occurred at 28.2 ± 5.79,
23.3 ± 4.24, 32.4 ± 9.46 and 27.7 ± 5.33% of the MIF, respectively. The coefficient of variation (CV) of
MPV at optimum MPP ranged from 7.4% to 9.7%, while the CV of %MIF ranged from 18.2% to 29.2%.
The MPV is a more precise indicator of the optimum loads than the percentages of MIF due to its low
inter-subject variability as expressed by CV. Therefore, MPV can be used to determine the optimum
power load in the four investigated exercises.

Introduction determining 1-RM values for large groups of athletes is usually

very labour-intensive (Loturco et al., 2015e), added to which, it
Muscle strength-power capacities are determinant factors of
has been suggested that this assessment may expose those
competitive performance in several sports (Loturco et al.,
being tested to increased injury risk (Brown & Weir, 2001;
2015b; Loturco, Ugrinowitsch, Tricoli, Pivetti, & Roschel,
Chapman, Whitehead, & Binkert, 1998). Another possible way
2013b; Silva, Nassis, & Rebelo, 2015). A recent systematic
to determine the muscle power training loads is by using the
review revealed that traditional strength training programmes
distinct percentages of the maximal isometric force (MIF)
(i.e., 3–6 sets of 4–10 repetitions of 70–88% of 1 repetition
(Duchateau & Hainaut, 1984; Haff et al., 2005, 1997; Kaneko,
maximum [1-RM]), undertaken 2–4 times per week, are cap-
Fuchimoto, Toji, & Suei, 1983), which necessarily depends on
able of eliciting large development of muscle strength and
expensive and impractical force plates. Therefore, it would be
power capacities in contact team sports (Mcmaster, Gill,
recommended to search for new methods capable of provid-
Cronin, & Mcguigan, 2013). However, the authors suggest
ing accurate measures for determining the muscle power
that the transference effects of the increases provided by the
training loads, avoiding excessive time consumption in top-
power-ballistic training on the neuromuscular abilities of these
level sports.
athletes remain inconclusive. This lack of scientific consistency
An applied alternative to the traditional maximum strength
is possibly regarded to the wide variation of training methods
assessments is to use immediate measures of the bar velocity
used in studies targeting the development of muscle power in
to estimate the participants’ optimum power loads (Loturco
athletes.
et al., 2015c). In this regard, mean power and peak power have
Recently, the possibility of enhancing the neuromuscular
been shown to be maximised at bar velocities close to 1 m·s−1,
abilities in trained participants using a range of loads capable
in both bench press (BP) and squat exercises (Izquierdo,
of eliciting the maximum power outputs in a given exercise
Hakkinen, Gonzalez-Badillo, Ibanez, & Gorostiaga, 2002;
has been advocated by some authors. Traditionally, this “opti-
Mcbride, Haines, & Kirby, 2011). More recently, mean propul-
mum range of loads” is determined based on relative mea-
sive power (MPP) has been used to assess and train highly
surements of the maximum dynamic strength (i.e., 1-RM) and
trained participants since Sanchez-Medina, Perez, and
varies from 0% to 80% of 1-RM, depending on the exercise
Gonzalez-Badillo (2010) demonstrated that this variable can
and method utilised to assess the muscle power (Cormie,
better reflect the differences in the neuromuscular potential
Mcguigan, & Newton, 2011; Kawamori & Haff, 2004). Besides
between two given individuals. Indeed, it has been shown that
this wide disparity in the provided power measures,
the jump squat (JS) MPP is highly associated with the actual

CONTACT Irineu Loturco irineu.loturco@terra.com.br Nucleus of High Performance in Sport, Avenida Padre José Maria, 555, CEP: 04753-060, Santo Amaro,
São Paulo-SP, Brazil
© 2016 Informa UK Limited, trading as Taylor & Francis Group
 2 I. LOTURCO ET AL.

performance obtained by elite athletes in specific sport tasks 180.2 ± 7.3 cm) volunteered to participate in this study. The
such as jumping, sprinting (Loturco et al., 2015a, 2015d) and rugby players were tested during the competitive phase of
punching impact (Loturco, Artioli, Kobal, Gil, & Franchini, 2014; training, 1 week before one of the most important competi-
Loturco et al., 2016). tions of the season (a phase of the Rugby Sevens World
Power production is enhanced when one or both compo- Series), suggesting that athletes were close to or at peak
nents of the power equation (i.e., Power = Force × Velocity) performance. A local Ethics Committee approved this study,
are enhanced. Interestingly, it seems that there exists a narrow and all participants were informed of the inherent risks and
range of velocities capable of optimising the MPP production. benefits, before signing an informed consent form.
For instance, it was shown that the optimum power load in
the JS occurs at a bar-mean propulsive velocity (MPV) of ≈
Study design
1 m·s−1 in athletes from different sports and with different
training backgrounds (e.g., power track & field athletes, endur- In this cross-sectional study, all athletes were previously famil-
ance runners and soccer players) (Loturco et al., 2015c). For iarised with the exercises used in this investigation and were
this reason, it is rational to investigate whether this mechan- involved in the same training routine in the weeks prior to
ical phenomenon occurs in other exercises executed using the study commencement. The athletes arrived at the sports
upper extremities [i.e., bench throw (BT)] or under different laboratory in a fasted state for 2 h and free of caffeine or
kinematic/dynamic conditions [i.e., half squat (HS) instead of alcohol consumption for at least 24 h. The assessments were
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JS], when the variable analysed is also related to the propul- performed on two consecutive days in the following order:
sive phase of the lifting (i.e., MPV). day 1 morning: maximum MPP in the JS and BP exercises; day
Due to the mechanical characteristics of “bench exercises” 1 afternoon: MIF in the HS and BP exercises; day 2 morning:
[performed without using the body mass (BM) as overload], it maximum MPP in the HS and BT exercises. An interval of at
could be expected that the athletes will achieve higher bar least 30 min was allowed between exercises. Before perform-
velocities in these movements than those achieved in exer- ing each test session, the athletes completed a 20 min stan-
cises executed against the individual’s BM (i.e., jumping exer- dardised warm-up, including 15 min of general (i.e., 10 min
cises). Hypothetically, it is expected that these kinematic running at a moderate pace followed by 5 min of lower-limb
aspects result in distinct dynamic conditions between these active stretching) and 5 min of test-specific exercises (i.e.,
movements, determining that the optimum range of loads in submaximal attempts at HS and BP exercises).
upper extremities occur at higher ranges of velocities than
those observed in jump movements. Still, it is plausible to
Mean propulsive power
assume that the ballistic exercises (JS and BT) allow for high
forces to be generated in light load situations due to the MPP was measured in the JS, HS, BP and BT exercises; all
continued acceleration throughout the movement (Cormie performed on a Smith-Machine (Hammer Strength
et al., 2011). Conversely, the power production in the tradi- Equipment, Rosemont, IL, USA). The athletes were instructed
tional exercises (HS and BP) should be optimised with higher to execute three repetitions at maximal velocity for each load,
loads moved at lower MPVs. with a 5 min interval provided between sets. The test started
Furthermore, based on our previous research (Loturco at a load corresponding to 40% of the individual BM in the JS
et al., 2015c), we expected that the bar velocities would and HS, and 30% in the BP and BT. A load of 10% of BM for JS
demonstrate less inter-subject variability than that related to and HS, and 5% of BM for BP and BT was gradually added in
maximum strength measurements to identify the optimum each set until a clear decrement in the MPP was observed. In
power zones of the different strength-power exercises, inde- the JS, the athletes executed a knee flexion until the thigh
pendent of their mechanical characteristics. If it holds true, was parallel to the ground and, after a verbal command,
sport practitioners could use this simple and time-saving mea- jumped as fast as possible without their shoulder losing
surements to assess and train their athletes, instead of using contact with the barbell. The HS was executed in a similar
traditional and time-consuming methods based on maximal fashion to the JS, except that the participants were instructed
dynamic strength tests. Therefore, the purposes of this study to move the bar as fast as possible without losing foot
were to test whether (1) the bar velocity is a more precise contact with the ground. During the BT, the athletes were
indicator (than the related maximum strength measurements) instructed to lower the bar in a controlled manner until the
of the optimum power loads; (2) there are fixed MPVs capable barbell lightly touched their chest and then to throw the bar
of maximising the respective MPP during the execution of the as fast as possible. In the BP exercise, the participants were
four investigated exercises (i.e., BP, BT, HS and JS); and (3) also instructed to move the load as fast as possible; however,
there are differences in the MPP and MPV (at the optimum they could not lose the contact with the bar. To determine
power zones) between ballistic and traditional exercises. MPP, a linear transducer (T-Force, Dynamic Measurement
System; Ergotech Consulting S.L., Murcia, Spain) was attached
at the lateral extremity of the Smith-Machine bar, at the left
Methods side of the athlete. The T-Force device consists of a cable-
extension linear velocity transducer interfaced to a computer
Participants
by means of a 14-bit resolution analog-to-digital data acquisi-
Seventeen male rugby sevens players from the Brazilian tion board and specific software, able to automatically calcu-
national team (24.4 ± 3.4 years; 88.0 ± 7.3 kg; late the relevant mechanical parameters of each repetition,
 JOURNAL OF SPORTS SCIENCES 3

providing real-time information about the lifting, and storing

kinetic and kinematic data for further analysis. The vertical
instantaneous velocity (v) was sampled at a frequency of
1000 Hz. Eccentric (negative v) and concentric (positive v)
phases of the movement were automatically detected by
the system attending to the sign of the velocity signal. The
derived mechanical variables were calculated by the software
as follows: displacement was obtained by integration of v
data with respect to time; instantaneous acceleration (a)
was obtained from differentiation of v with respect to time;
instantaneous force (F) was calculated as F = m · (a + g),
where m is the moving mass (kg) and g is the acceleration
due to gravity; instantaneous power output resulted from the
product of the vertical applied force and bar velocity
(P = F · v). Validity and reliability of this system were pre-
viously established, presenting an associated error of < 0.25%,
while displacement was accurate to ±0.5 mm (Sanchez-
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Medina et al., 2010). After data acquisition, the vertical instan-

Figure 1. Equipment for assessing the maximum isometric force (MIF) in bench
taneous velocity was smoothed with a fourth-order low-pass press exercise.
Butterworth filter, with a cut-off frequency of 10 Hz. A digital
filter with no phase shift was subsequently applied to the
data. The maximum MPP, and the respective MPV, load and
Statistical analysis
percentage of BM associated with the maximum MPP
(MPPload and MPPBM, respectively), and the MPP divided by Data are presented as mean ± standard deviation (SD). The
the athletes’ BM (MPP REL) obtained in each exercise were normality of data was tested using the Shapiro–Wilk test. The
used for analysis purposes. Test–retest reliability for mechan- paired t-test was used to compare the variables between the
ical power outputs as measured by the coefficient of variation ballistic (JS and BT) and non-ballistic exercises (HS and BP). The
(CV) was <5% (Loturco et al., 2015c). analysis based on effect sizes (ES) (Cohen, 1988) was used to
analyse the magnitude of differences between ballistic (JS and
BT) and non-ballistic (HS and BP) exercises. The magnitudes of
the ES were interpreted using the thresholds proposed by
MIF assessment
Rhea (2004) for highly trained participants, as follows: <0.25,
The MIF was determined for the upper and lower limbs 0.25–0.50, 0.50–1 and >1 for trivial, small, moderate and large,
using the HS and BP exercises, both performed on a respectively. The inter-subject CV was calculated to analyse
Smith-Machine (Hammer Strength Equipment, Rosemont, the variability of the maximum MPP estimation based on the
IL, USA). The HS was executed in a “half position” and the MPV, the percentage of MIF (MPPMIF) and the percentage of
knee angle was fixed at ≈90°, with the intention of max- BM. A low CV value indicates a more consistent (precise)
imising peak force in the HS, as previously reported measurement (Shechtman, 2013). The significance level was
(Escamilla, 2001). For BP, the barbell was positioned across set as P < 0.05.
the athletes’ chest, at the level of their nipples. The athletes
held the barbell at shoulder width, with an initial elbow
angle of ≈90° (angle between the arm and forearm) (Terzis,
Results
Georgiadis, Vassiliadou, & Manta, 2003). For both measure-
ments, after a starting command, the participants exerted The MIF attained by the athletes in the HS exercise was
force as rapidly as possible against a mechanically fixed bar, 3612.5 ± 414.9 N and in the BP, 1317.9 ± 181.7 N. Figures 2
for 5 s. The MIF represented the maximum force output and 3 depict the MPP (highlighting the maximum values of
(peak force) collected in both exercises (i.e., HS and BP), muscle power) in the upper and lower limb ballistic and non-
and achieved over the force–time curve during the course ballistic exercises, in relation to the loads as expressed by
of 5 s, using a force platform with custom-designed soft- percentage of BM.
ware (AccuPower, AMTI, Graz, Austria), which sampled at a Table 1 shows the comparisons of the absolute MPP, MPP
rate of 400 Hz, and based on a frequency content analysis REL, MPPload, MPPBM, MPPMIF and MPV between the JS and HS
filtered using a digital second-order low-pass Butterworth exercises. The JS exercise presented higher MPP, MPP REL and
filter with a cut-off frequency of 20 Hz (Walsh, Ford, Bangen, MPV, and lower MPPload and MPPBM than the HS exercise (with
Myer, & Hewett, 2006). The platform was fixed to the floor ES ranging from moderate to large). The MPPMIF was not
using a specific base. For BP testing, a bench was fixed onto different between the exercises (although a moderate ES was
the platform and the force applied against the barbell was noted).
transmitted by the bench to the force platform in the Table 2 presents the comparisons of the absolute MPP, MPP
vertical plane (Figure 1). Strong verbal encouragement was REL, MPPload MPPBM, MPPFIM and MPV between the BT and BP
provided during the attempts. exercises. The BP exercise presented higher MPP, MPP REL,
 4 I. LOTURCO ET AL.

Figure 2. Mean propulsive power (MPP) progression in relation to the loads expressed by the percentage of body mass during jump squat and half-squat exercises.
The full symbols represent the respective maximum MPP.
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Figure 3. Mean propulsive power (MPP) progression in relation to the loads expressed by the percentage of body mass during bench press and bench throw
exercises. The full symbols represent the respective maximum MPP.

Table 1. Comparisons between lower limb ballistic and non-ballistic exercises.

ES [95% CI]
JS HS Mean difference [95% CI] Rating
MPP (W) 977.4 ± 156.2 897.9 ± 157.7* 79.6 [−33.8 to 192.9] 0.51 [−0.21 to 1.20]
Moderate
−1
MPP REL (W·kg ) 11.1 ± 1.74 10.2 ± 1.77* 0.89 [−0.38 to 2.16] 0.51 [−0.21 to 1.20]
Moderate
MPPload (kg) 74.5 ± 10.6 85.2 ± 14.7* −10.7 [−20.0 to −1.45] −0.83 [−1.53 to 0.09]
Moderate
MPPBM (%) 84.8 ± 11.6 97.0 ± 16.9* −12.2 [−22.7 to −1.73] −0.84 [−1.54 to −0.10]
Moderate
MPPMIF (%) 28.2 ± 5.79 32.4 ± 9.46 −4.20 [−10.3 to 1.89] −0.54 [−1.27 to 0.23]
Moderate
−1
MPV (m·s ) 1.02 ± 0.07 0.93 ± 0.08* 0.09 [0.04 to 0.14] 1.20 [0.42 to 1.92]
Large
CI: confidence interval; HS: half-squat exercise; JS: jump squat exercise; MPP: mean propulsive power; MPP REL: MPP relative to body
mass; MPPload: load associated with the maximum MPP; MPPBM: MPP load expressed as percentage of body mass; MPPMIF: MPP
load expressed as percentage of maximum isometric force; MPV: mean propulsive power associated with the maximum MPP.
*P < 0.05.
 JOURNAL OF SPORTS SCIENCES 5

Table 2. Comparisons between upper limb ballistic and non-ballistic exercises.

ES [95% CI]
BT BP Mean difference [95% CI] Rating
MPP (W) 697.8 ± 70.4 743.4 ± 100.1* −45.6 [−106.1 to 14.8] −0.53 [−1.20 to 0.17]
Moderate
−1
MPP REL (W·kg ) 7.98 ± 0.87 8.49 ± 1.21* −0.51 [−1.25 to– 0.23] −0.48 [−1.15 to 0.21]
Small
MPPload (kg) 30.3 ± 3.80 35.7 ± 7.80* −5.40 [−9.69 to −1.11] −0.88 [−1.56 to −0.16]
Moderate
MPPBM (%) 32.7 ± 9.80 40.9 ± 9.50* −8.20 [−14.9 to −1.46] −0.85 [−1.53 to −0.13]
Moderate
MPPMIF (%) 23.3 ± 4.24 27.7 ± 5.33* −4.40 [−8.14 to 0.66] −0.91 [−1.66 to −0.11]
Moderate
−1
MPV (m·s ) 1.67 ± 0.15 1.40 ± 0.13* 0.27 [0.17 to 0.37] 1.92 [1.07 to 2.69]
Large
CI: confidence interval; BP: bench press exercise; BT: bench throw exercise; MPP: mean propulsive power; MPP REL: MPP relative to body mass; MPPload: load
associated with the maximum MPP; MPPBM: MPP load expressed as percentage of body mass; MPPMIF: MPP load expressed as percentage of maximum isometric
force; MPV: mean propulsive power associated with the maximum MPP.
*P < 0.05.
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Table 3. Inter-subject coefficient of variation of the maximum mean may be recognised as rapid, valid and reliable measurements
propulsive power estimation based on the mean propulsive velocity of functional strength (in addition to being highly correlated
(MPV), % of maximum isometric force (MIF), and % of body mass (BM)
in the different ballistic and non-ballistic exercises. with 1-RM tests) (Bazyler, Beckham, & Sato, 2014; Mcguigan &
MPV % MIF % BM Winchester, 2008; Ugarkovic, Matavulj, Kukolj, & Jaric, 2002;
Jump squat 7.4 20.5 13.7 Wilson & Murphy, 1996), the lower consistency of the relative
Half squat 9.4 29.2 24.6 MIF (in comparison to MPV) in identifying the “optimum range
Bench throw 9.3 18.2 15.8 of loads” brings into question the use of maximum strength
Bench press 9.7 19.2 23.5
tests to define the power training loads. Importantly, the
velocity-based concept does not demand that athletes exe-
MPPload, MPPBM and MPPFIM, and lower MPV than the BT cute a previous test, enabling coaches to determine and
exercise (with ES ranging from small to large). adjust the optimum loads in real time, throughout the actual
Table 3 shows the CV for the maximum MPP estimated training sessions. Furthermore, it has already been demon-
based on the MPV, % of MIF and % of BM in the different strated that the optimum training velocities are not modified
ballistic (JS and BT) and non-ballistic exercises (HS and BP). The by the participants’ strength levels (and their respective train-
CV associated with MPV was the only one <10%. ing backgrounds) (Loturco et al., 2015c). This might be an
important advantage of this training system since it is
expected that top-level athletes increase their levels of muscle
power throughout a given training period. Using this concept,
Discussion irrespective of the magnitude of the muscle power changes,
This is the first study to identify and compare the MPVs cap- coaches can make inferences about training adaptations.
able of optimising the MPP among four different strength- Therefore, from this point on, the strength and conditioning
power exercises. An important finding reported herein is coaches can precisely monitor their athletes and regulate the
that, independent of the exercise type (i.e., ballistic or non- training loads on a daily basis using the four MPVs indicated in
ballistic), the MPV is a precise (with low inter-subject variabil- this study (Table 2).
ity; CV < 10%) and practical indicator of the optimum power As expected, the ballistic exercises (JS and BT) produced
zone. Curiously, although the ballistic JS generates higher their higher MPP values at higher MPVs (in comparison to the
values of MPP than the traditional HS, the same does not similar traditional squat press and BP exercises). Notably,
occur when comparing BT with BP. Possibly, the ballistic con- whereas JS MPP was greater than squat MPP, BP MPP was
dition does not maximise the “maximum power production” in greater than BT MPP. These results are in disagreement with
strength-power exercises performed using the upper those obtained by Newton, Kraemer, Hakkinen, Humphries,
extremities. and Murphy (1996), who reported that power performance
The maximal mechanical power has been thought to occur was significantly higher during explosive BT (compared to
at a load corresponding to 30% of maximum isometric presses). Of note, in that study, the authors used a fixed
strength (Kaneko et al., 1983; Kawamori & Haff, 2004; Wilson, percentage of the maximum dynamic strength (i.e., 45% of
Newton, Murphy, & Humphries, 1993) or 0–80% of 1-RM 1-RM) to test for kinematic and kinetic differences between
(Cormie et al., 2011; Kawamori & Haff, 2004; Newton et al., the exercise types. As aforementioned, due to the continuous
1997). Our results partially confirm these findings since our acceleration applied throughout the lifting, this light-loading
participants were able to achieve their highest values of MPP condition favours the force-power generation more during the
at a range between 23% and 32% of their MIF (inter-subject explosive “throw” movements. In fact, a systematic review
CV ≈ 20%, for all tested exercises). Although isometric tests (Cormie et al., 2011) of power training considerations revealed
 6 I. LOTURCO ET AL.

that, for optimising muscle power, the ballistic exercises must optimum power zone (instead of HSs) (Lyttle, Wilson, &
be performed with light to moderate loads ranging from 0% Ostrowski, 1996; Schuna & Christensen, 2010; Wilson et al.,
to 50% of 1-RM and the traditional weightlifting exercises with 1993). Conversely, for upper extremities, the traditional BPs
heavier loads, ranging from 50% to 90% of 1-RM. Our data seem to be more indicated than the explosive BTs to increase
confirm and extend these previous observations since the the maximum capacity of generating muscle power, at least
greater values of MPP in both the BP and HS exercises were when these exercises are executed using their respective opti-
achieved using loads ≈5% heavier (when compared to the MIF mum power loads. Nevertheless, if the athlete has the necessity
values) than the loads used to obtain the higher MPPs in their to produce considerable values of power at higher velocities
ballistic forms (BT and JS). under very light loaded/unloaded conditions (e.g., punching or
The differences between the power outputs collected in bal- ball-throwing situations), it is highly recommended to perform
listic exercises in the upper and lower extremities are possibly BTs during the specific power training sessions (Newton et al.,
related to the mechanical characteristics of these exercises. 1996; Szymanski, 2012).
Different from the BT, during a JS – apart from the external We acknowledge that our study is limited to a cross-sectional
load – the mass of the body must be fully moved at the take- observation testing only four of the most widely used exercises
off (Dugan, Doyle, Humphries, Hasson, & Newton, 2004). Taking (i.e., HS, JS, BP and BT) in strength-power training. In addition,
into account the parametric relationship between the applied this investigation was performed using team sport athletes with
force and the resultant movement velocity (i.e., the higher the large experience in strength-power training; thus, these results
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force, the lower the velocity) (Loturco et al., 2015b), it is predict- cannot be directly extrapolated to individuals with different
able that the explosive throw movements (i.e., BT) achieve training backgrounds and strength levels. More studies are
expressively higher bar velocities than the overloaded JSs. needed to compare the two modes of exercise execution (i.e.,
Consequently, it is also expected that this mechanical relation- traditional or ballistic) and their respective adaptations in long-
ship provokes specific shifts in the force–velocity curves of dis- itudinal designs, expanding these observations to other exercises
tinct exercises, thus defining their optimum power zones. This and other groups of athletes, from team and individual sports
individual optimum force–velocity profile corresponds to the specialties. Additionally, the MPP values were not expressed
best balance between force and velocity abilities (Loturco et al., relative to the dynamic 1-RM test. Importantly, our sample was
2015c; Samozino, Rejc, Di Prampero, Belli, & Morin, 2012). composed of elite rugby players (from a national team) and this
Nevertheless, a prominent imbalance in this relationship (i.e., a study was performed 1 week before the most important compe-
very high velocity) may enhance the power production in a tition of the season. Therefore, in consensus with the technical
specific portion of the force–velocity curve (i.e., the high-velocity, staff, we decided to use maximum isometric measurements
low-force end of the curve) (Kanehisa & Miyashita, 1983; Kaneko (rather than maximum dynamic measurements) to determine
et al., 1983; Loturco et al., 2013a, 2015b). For instance, in compar- the participants’ strength levels. This decision was based on the
ison with the BP, the optimum power zone in BT is attained at an perceived lower risks and the actual time taken to perform
MPV ≈ 20% higher (i.e., 1.67 vs. 1.40 m·s−1, for BT and BP, isometric assessments.
respectively), and using a relative range of loads ≈ 8% lighter In summary, this study demonstrated that the MPV is a more
(i.e., 23.3% vs. 27.7% of the MIF, for BT and BP, respectively). precise indicator of the optimum power load than the relative
Under this mechanically unfavourable force–velocity balance (in values of maximum isometric strength. Furthermore, in a homo-
favour of velocity), the load magnitude assumes a secondary role geneous group of elite athletes, even the percentages of the
in generating muscle power during the explosive throws. On the individual BM (inter-subject CV ≈ 13.7–24.6%) seem to be better
other hand, when compared to the traditional HS, the ballistic JS (and much more practical) references to indicate the optimum
has its MPP optimised at an MPV ≈ 7% higher (i.e., 1.02 vs. power zones than the strength-based measurements (inter-sub-
0.93 m·s−1, for JS and HS, respectively) and at a range of loads ject CV ≈ 18.2–29.2%). Importantly, due to the mechanical char-
≈9% lighter (i.e., 28.2% vs. 32.4% of the MIF, for JS and HS, acteristics of the throw movements, the maximum values of MPP
respectively). After considering these kinematic and kinetic para- are not increased during the explosive BT (in relation to the
meters, it is possible to assert that the maximum MPP in JS occurs traditional BP). For lower extremities, the ballistic JS can really
under more balanced mechanical conditions than the MPP of the enhance the power production and should be preferred to HS for
BT. Whilst the MPV is highly optimised, the magnitude of the developing power-related abilities. It is crucial to emphasise that,
applied force is substantially compromised at the BT’s optimum in this research, the power outputs were collected at the opti-
power zone. In contrast, in JSs, the balanced relationship mum power zones: a specific range of loads where the mechan-
between both components of the power equation (i.e., force ical muscle power production is maximised. Using the same
and velocity) is capable of greatly enhancing the power produc- relative range of loads (i.e., 45% of 1-RM) (Newton et al., 1996),
tion. As a result, while JSs produce higher power outputs than in some specific cases, the power generated in explosive exer-
HSs, the “more balanced BPs” produce higher power outputs cises performed with the upper extremities can be higher than
than the “unbalanced BTs”. Considering this novel information, the power generated in traditional strength exercises.
the instructions given to the athletes may have a central role in
regulating their neuromuscular adaptations. In this regard, if the
Conclusion
main objective of the (lower limb) power training is to increase
the maximum power production at both ends of the force– From a practical standpoint, by using a linear encoder and the
velocity curve (i.e., high-force/low-velocity and low-force/high- four MPVs provided here, sports practitioners can adjust the
velocity portions), it is reasonable to perform ballistic JSs at the training intensities of their athletes on a daily basis when
 JOURNAL OF SPORTS SCIENCES 7

executing JSs, HSs, BTs and BPs. Furthermore, with this velo- Loturco, I., Artioli, G. G., Kobal, R., Gil, S., & Franchini, E. (2014). Predicting
city-based concept, it is possible to identify with a high degree punching acceleration from selected strength and power variables in
elite karate athletes: A multiple regression analysis. Journal of Strength
of accuracy (CV < 10%) the optimum power loads in these
and Conditioning Research, 28(7), 1826–1832. doi:10.1519/
referred exercises. Still, using the related exercises’ MPVs, the JSC.0000000000000329
coaches can avoid the laborious maximum dynamic strength Loturco, I., D’angelo, R. A., Fernandes, V., Gil, S., Kobal, R., Abad, C. C. C.,. . .
tests, with the advantage of being able to more precisely Nakamura, F. Y. (2015a). Relationship between sprint ability and
prescribe power training loads. Finally, further studies should loaded/unloaded jump tests in elite sprinters. Journal of Strength and
Conditioning Research, 29(3), 758–764. doi:10.1519/
determine whether these fixed velocities occur in other
JSC.0000000000000660
strength-power exercises. Loturco, I., Nakamura, F. Y., Artioli, G. G., Kobal, R., Kitamura, K., Cal Abad,
C. C.,. . . Franchini, E. (2016). Strength and power qualities are highly
associated with punching impact in elite amateur boxers. Journal of
Disclosure statement Strength and Conditioning Research, 30(1), 109–116. doi:10.1519/
JSC.0000000000001075
No potential conflict of interest was reported by the authors. Loturco, I., Nakamura, F. Y., Kobal, R., Gil, S., Cal Abad, C. C., Cuniyochi, R.,. . .
Roschel, H. (2015b). Training for power and speed: Effects of increasing
or decreasing jump-squat velocity in elite young soccer players. Journal
of Strength and Conditioning Research, 29(10), 2771–2779. doi:10.1519/
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