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An Examination of Training on the VertiMax Resisted Jumping Device for Improvements in Lower Body Power in Highly Trained College Athletes


Abstract and Figures

Training to develop superior muscular power has become a key component to most progressive sport conditioning programs. Conventional resistance training, plyometrics, and speed/agility modalities have all been employed in an effort to realize superlative combinations of training stimuli. New training devices such as the VertiMax resisted jump trainer are marketed as a means of improving lower body reactive power. The purpose of this study was to evaluate the effectiveness of the VertiMax, in combination with traditional training modalities, for improvements in lower body power among highly trained athletes. Forty men and women Division I collegiate athletes representing the sports of baseball, basketball, soccer, gymnastics, and track completed a 12-week mixed-methods training program. Two groups were constructed with both groups performing the same conventional resistance training and strength training exercises. The training control group performed traditional plyometric exercises while the experimental group performed similar loaded jump training on the VertiMax. Lower body power was measured before and after the training program by the TENDO FiTROdyne Powerlizer and statistically compared for differences between groups. Data analyses identified a significant (p < 0.05) and meaningful difference between power development among the 2 groups, with the VertiMax eliciting a greater treatment effect (effect size = 0.54) over conventional resistance and plyometric training alone (effect size = 0.09). These data convincingly demonstrate that the VertiMax represents an effective strategy for developing lower body power among trained college athletes, when combined with traditional strength and conditioning approaches.
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Department of Interdisciplinary Health Sciences, AT Still University, Mesa, Arizona;
Department of Exercise Science,
Mesa Community College, Mesa, Arizona;
European University of Madrid, Madrid, Spain;
San Francisco Giants, San Francisco, California
Training to develop superior muscular power has become a key
component to most progressive sport conditioning programs.
Conventional resistance training, plyometrics, and speed/agility
modalities have all been employed in an effort to realize super-
lative combinations of training stimuli. New training devices
such as the VertiMax resisted jump trainer are marketed as
a means of improving lower body reactive power. The purpose
of this study was to evaluate the effectiveness of the VertiMax,
in combination with traditional training modalities, for improve-
ments in lower body power among highly trained athletes. Forty
men and women Division I collegiate athletes representing the
sports of baseball, basketball, soccer, gymnastics, and track
completed a 12-week mixed-methods training program. Two
groups were constructed with both groups performing the
same conventional resistance training and strength training
exercises. The training control group performed traditional plyo-
metric exercises while the experimental group performed similar
loaded jump training on the VertiMax. Lower body power was
measured before and after the training program by the TENDO
FiTROdyne Powerlizer and statistically compared for differ-
ences between groups. Data analyses identified a significant
(p,0.05) and meaningful difference between power develop-
ment among the 2 groups, with the VertiMax eliciting a greater
treatment effect (effect size = 0.54) over conventional
resistance and plyometric training alone (effect size = 0.09).
These data convincingly demonstrate that the VertiMax repre-
sents an effective strategy for developing lower body power
among trained college athletes, when combined with traditional
strength and conditioning approaches.
KEY WORDS VertiMax, plyometric exercise, power, speed,
physical conditioning
For all athletes, the ability to transfer training-
induced physiological adaptations to performance
in skill-related activity is essential for optimal func-
tioning, injury reduction, and competitive success.
Just as inferior skill limits the extent of athletic succession, for
today’s aspiring athlete, inferior physical fitness will handicap
even the most skilled individual. Clearly, the extent to which
fitness influences performance is fundamentally distinctive.
For some sports, physical conditioning and athletic practice
are synonymous, as ability is dictated principally by fitness
capacities (i.e., marathon running, sprint cycling, power
lifting). In contrast, many other activities are characterized by
a diverse multidimensional set of physiological competencies,
underscoring the importance of specific, effectual training
modalities. By combining the appropriate training stimuli
with the appropriate quantity and quality of skilled move-
ment, coaches and sport performance specialists may col-
laborate to optimize training efficiency and elicit the most
transferable adaptations.
In combination with quality of movement, training to
stimulate muscular adaptation for peak power output resides
as a principal developmental objective. Collegiate athletes are
traditionally introduced to explosive lifting early in the off-
season as an adjunct to important functional and conventional
power lifting exercises. Ultimately, the inclusion of explosive
lifting as a primary training tenet is done to stimulate neu-
romuscular adaptation, supporting the development and
enhancement of muscular rate of force development and peak
power. This customary training agenda manifests as a shift in
Address correspondence to Matthew R. Rhea,
Journal of Strength and Conditioning Research
Ó2008 National Strength and Conditioning Association
VOLUME 22 | NUMBER 3 | MAY 2008 | 735
emphasis from training the basic force production capacities
of muscle, to developing muscular contraction velocity and
movement speed, and ultimately to preparing the musculo-
skeletal system for performance in powerful athletic events.
However, despite proven efficacy to promote such specialized
adaptations, many professionals have abandoned traditional
explosive lifting techniques, citing safety concerns, and/or
inefficient time expenditure.
In an effort to supplement/replace traditional approaches,
various training technologies and prescription innovations
have been devised to elicit similar muscular power adaptation.
Lower load, high-speed training has gained considerable
popularity among professionals, as well as the sport science
community. Although the recommendation to train with
high speed is not a novel approach, little is known about the
optimal implementation strategy. One technique, in partic-
ular, loaded jump training, has received considerable interest,
as of late (9). Conceivably, overloading a vertical jump may
be a superior means for development of rate of force produc-
tion and peak power output, as execution is not heavily
contingent on technique, thus enabling athletes of various
backgrounds to productively train. Many research investi-
gations have supported the use of jump training modalities,
demonstrating significant enhancements in peak power
output, jumping ability, sprint acceleration, rate of force
development, and general strength-power profiles (9).
Albeit popular for overloading high-velocity concentric
muscle actions and reducing technique vulnerabilities, loaded
jump training may be similarly valuable for development of
muscle eccentric deceleration. Most often considered a pro-
tective barrier to injury, coordinated eccentric muscular
recruitment is also a fundamental requisite for jumping ability
(9). Case in point, during the countermovement phase of
a jump (i.e., the transition phase from eccentric to concentric,
otherwise known as the amortization phase of a plyometric
movement), stored elastic energy from the prestretched
muscle is transferred to optimize mechanical recoil of the
musculotendinous unit. By deliberately accentuating the
eccentric deceleration phase of a multijoint movement, spe-
cialized training interventions may be designed to induce
neuromuscular adaptations in the stretch-shortening cycle
(SSC), supporting both voluntary activation and inhibitory
and/or facilitatory reflexes (2). Collectively, these neural
adaptations may support enhanced mechanical efficiency of
jumping (1,3,13–16), improved muscle-activation patterning
and dynamic joint stability (4), and increased agonist muscle
innervation through the stretch reflex (5,6,12,17), leading to
increased joint moments, greater ground reaction force, and
superior jumping ability (11).
Seemingly, the benefits of loaded jump training have far-
reaching implications for preparing athletes to compete in
similar dynamic activities. However, many dynamic move-
ments rely on explosive contractions involving longer concen-
tric actions than experienced during brief SSC movements,
and may be limited by the ability of the muscle to produce
force during fast contraction velocities (18). Evidence has
suggested that combining heavy resistance training with
high-speed exercises may be the optimal technique for elic-
iting neuromuscular adaptation to support both the stretch
reflex and rate of force development, as well as for improve-
ment in a variety of performance variables concerned with
maximal strength and power (8). Independently, heavy-
resistance–low-velocity training as well as low-resistance–
high-velocity training may effectively generate improve-
ments at the high force end of the force-velocity curve and
toward the high-velocity end of the force-velocity curve,
respectively. In combination, it is plausible that training for
strength and speed may elicit a powerful synergistic effect,
and maximize neuromuscular development for peak power
output and explosive athletic performance.
Failure to optimize each of the basic force-producing
characteristics of the neuromuscular and musculoskeletal
systems may diminish the developmental potential of mus-
cular power adaptation and expression across a continuum of
high-force and high-speed movements. Specifically, the
combination of various training methods to elicit a maximal
transference in power output is critical for explosive athletes.
Of particular importance to advanced trainees such as col-
legiate athletes, a progression in specialized stimuli to accom-
pany increased training experience is essential to sustain
continued adaptation (19,21,23). As athletes become more
highly trained, the stimulus applied during conditioning must
increase to continue to overload the neuromuscular system
and elicit a training adaptation. The development of training
aids to enable this progressive overload is an industrious
pursuit. While many such aids are currently marketed, few
have demonstrated effectiveness among athletic populations.
The purpose of this investigation was to examine the effects
of a concurrent mixed-methods training protocol (i.e., tra-
ditional power lifting and explosive lifting) supplemented
with loaded jump training using the VertiMax (VMax) resisted
jump training device compared to a traditional resistance/
plyometric training regimen on jumping ability and peak
power output in collegiate athletes. The VMax (Figure 1) is
a platform-based device with bungee attachments for the
waist, hands, and thighs. Strategic placement and adjustment
of bungee resistance allow for the performance of plyometric
jumping exercises with resistance added.
Experimental Approach to the Problem
Highly trained, NCAA Division I collegiate athletes from
various sports were recruited and assigned to either a standard
mixed-methods training program or a standard training
program plus loaded jump training. Although the men and
women athletes were from different sports and involved in
specific conditioning programs, both treatments were equally
represented for each involved sport subgroup. The assigned
treatments consisted of a 12-week intervention during each
Journal of Strength and Conditioning Research
VertiMax Jump Training
athlete’s respective off-season, which ultimately coincided
with the basic strength and strength/power phases of
training, respectively. Before and after the training inter-
ventions, athletes were tested on vertical jumping ability and
peak power output in order to assess the effectiveness of
treatment strategy, as well as the differences between groups.
Forty Division I collegiate athletes (n=26men,n=14women)
representing the sports of baseball, gymnastics, soccer, and
basketball were recruited for this 12-week training intervention
study. Before baseline testing, athletes were assigned to 1 of
2 groups: VMax group or training control (TCo) group.
Because there were slight variations in training programs for
each different sport, groups were composed equally of athletes
from each particular sport to protect against a confounded
experimental affect derived through differences in training.
Athletes from each sport were randomly assigned to a respec-
tive group, ensuring that equal numbers of athletes from a given
sport were placed in each group. Therefore, the only difference
in training across the 2 groups was the inclusion of resisted
jumping exercises on the VMax device. Both groups were
composed of 13 men and 7 women, each of whom committed
to adhering to the training protocol and refraining from per-
forming alternative or supplemental workouts. Compliance
with training was monitored by the researchers and strength
and conditioning staff responsible for training sessions. While
athletes in both groups missed training sessions, exclusion
criteria for analyses was set at anything in excess of 2 missed
workouts, over the entire 12-week training intervention;
however, no athlete met such criteria.
Power Measurements
Lower body peak power was identified through the use of
the TENDO FiTROdyne Powerlizer (Fitro-Dyne; Fitronic,
Bratislava, Slovakia) according to protocols suggested by
Jennings et al. (10). Athletes weighed-in immediately prior to
performing a maximal countermovement jump test. In order
to effectively test power output during the counter move-
ment vertical jump, the TENDO unit cord was attached to
the back waistband of each subject’s athletic shorts. This
arrangement allowed for the base of the TENDO FiTRO-
dyne unit to be positioned on the floor behind the athlete
during the test, in such a way that valid readings could be
obtained without impeding jump technique and/or perfor-
mance. In order to calculate power output in watts, each
athlete’s body mass was imported into the Fitrodyne
microcomputer. The TENDO unit proficiently computed
PP according to the speed of movement in the concentric
phase of the jump test, as well as each respective athlete’s
body mass. Certified strength and conditioning specialists
and investigators oversaw all testing processes to ensure
proper technique and safety (7).
Training Protocol
Both groups performed similar training programs composed
of free weight resistance training with lower body compound
exercises (e.g., back squat, powercleans, standard deadlifts,
dumbbell walking lunges, and Romanian deadlifts) (Table 1).
Figure 1. The VertiMax.
TABLE 1. Lower body exercises performed during
Resistance exercises (2–3 dwk
, 6–10
sets total, 80–90% 1RM)
Back squat
Dumbbell walking lunges
Romanian deadlifts
Sprint and plyometric exercises (1–2 dwk
10–15 repetitions per exercise)
20–40 yd sprints
Front/side hurdle jumps
Depth jumps
Split jumps
Additional exercises performed by the VertiMax
training group (1–2 dwk
Resisted quarter jumps: 2–4 sets, 8–10 jumps
Resisted half jumps: 2–4 sets, 5–10 jumps
Resisted split jumps: 2–4 sets, 5–10 jumps
VOLUME 22 | NUMBER 3 | MAY 2008 | 737
Journal of Strength and Conditioning Research
In conjunction with traditional resistance training, the TCo
group also performed running and plyometric drills, includ-
ing variable-distance sprints, split-squat jumps, variable-
height depth-jumps, and hurdle-jumps. Athletes from both
treatments followed a periodized training program with resis-
tance exercises performed 2–3 days per week, and sprint/
plyometric (TCo group) or sprint/VMax (VMax group)
training 1–2 days per week, for 12 total weeks. Volume of
resistance training exercises averaged 8 sets per muscle group
at a mean intensity of 80–90% of 1-repetition maximum
(1RM) (19,25). These training values were selected because
they have been shown to be the most operational com-
bination of training stimuli for eliciting maximal strength
among athletic populations (20). Sets and repetitions for each
exercise were periodized in daily undulating (24) fashion.
In addition to the traditional compound lower body lifts
and equated sprint work, the VMax group performed sup-
plementary exercises on the VMax V-6 training apparatus
(Genetic Potential; Tampa, Fla.). The VMax is a platform-
based unit complete with adjustable bungee chords that can
be attached to a waist belt worn by an athlete. To further
overload each movement, hand straps connected to bungee
chords were worn by all study athletes, allowing accentuated
resistance on the arm swing phase and spinal extension during
all jumping movements. Resistance on the bungee chords was
adjusted to apply more or less resistance when needed.
The 3 supplementary exercises performed by all subjects in
the VMax group were half squat jumps, quarter squat jumps,
and split squat jumps. Half squat jumps involved performing
8–10 jumps with a slight pause between each rep, while
quarter squat jumps were 5–10 jumps done repetitively with
no pauses. Depth of the countermovement for each of the
VMax-resisted squat jump exercises (i.e., half and quarter
squat jumps) was left to the discretion of the individual athlete
and depended on personal jumping technique; however, no
dramatic differences were observed between participants.
Spilt squat jumps were performed by instructing each
athlete to assume a deep lunge position with a flexed knee and
hip of the lead leg and fully extended hip of the trail leg. At his
or her discretion, each athlete then jumped as high as possible
(i.e., vertically) and, while in the air, switched the position of
each leg to decelerate in the oppositely situated lunge
position. Multiple repetitions were performed as quickly as
possible with no rest between
each jump. For all loaded jump
exercises on the VMax, resis-
tance on the bungee chords
was progressively increased
over the duration of 12 weeks
to provide appropriate pro-
gression in stress. Training
sessions on the VMax appara-
tus took place in groups of 4
athletes. After performing the
assigned number of repetitions,
an athlete would be disconnected from the chords and
directed to the end of the line, while the next athlete assumed
his or her place on the platform. This sequence resulted in
approximately 2 minutes of rest between each set of like
exercises on the VMax and approximately 5 minutes between
different loaded jump exercises. Two to 3 sets of each exercise
were performed.
Statistical Analyses
Descriptive data (mean and SD) for the various tests were
computed. At pre-test, the TCo group demonstrated sig-
nificantly lower power (2211.10 W) than the VMax group
(p,0.05). Therefore, change in power from pre- to post-
testing was calculated and analyzed by independent samples
t-test. Level of statistical significance was set at p#0.05, with
meaningfulness of differences determined by the use of effect
sizes (ESs). Effect sizes were calculated by determining the
difference between pre- and posttest means, divided by the
pretest SDs and interpreted according to a scale previously
proposed by Rhea (22).
Descriptive statistics from pre- and post-testing are shown in
Table 2. The average improvement in power observed in the
TCo group (+16.25 642.67 W) resulted in a very small ES of
0.09, which did not reach statistical significance (p.0.05).
The increase in power in the VMax group (+109.15 6107.69 W)
represented a moderate ES of 0.54 and was found to be
statistically different (p,0.05) from pretest power. Improv-
ement in power following training was found to differ
between groups (p,0.05) in favor of the VMax group (+92.9
665.01 W).
These data clearly demonstrated an added benefit of per-
forming loaded jump training exercises on the VMax appa-
ratus in conjunction with traditional preparatory strength and
conditioning modalities, when compared to strength/power
training alone. The large difference in power improvement
is quite substantial when considering that baseline power
measures in the VMax group were significantly higher than
those of the TCo group. Certainly, it was expected that sig-
nificantly greater initial peak power capacities could result in
TABLE 2. Results.
Group Pre-test (W) Post-test (W) Improvement ES
TCo 986.45 6176.11 1002.70 6187.88 +16.25 642.67 0.09
VMax 1197.55 6202.47* 1306.70 6188.67* +109.15 6107.69* 0.54*
ES = pre/post effect size; TCo = control group; VMax = VertiMax group.
*Groups differ at P,0.01.
Journal of Strength and Conditioning Research
VertiMax Jump Training
an overall diminished comparative test-retest improvement
for the VMax group; according to the principle of diminishing
returns. However, such an expectation was not realized at the
completion of the intervention and post-test, lending even
further support to the effectiveness and practical application
of this training device.
Comparing the improvements in power observed in the
current study to a recent study by Hoffman et al. (9) involving
resisted jump training on the Cormax Jump Squat Device
(Cormax Strength Power Systems, Valley City, ND), the
VMax group in the current study exceeded improvements in
lower body power (ES = 0.54) compared to both inter-
vention groups in the Hoffman et al. study (ES = 0.49 and
0.22, respectively). Therefore, it may be concluded that train-
ing on the VMax not only enhances lower body power
improvements compared to conventional resistance training
and plyometrics, it also exceeds the benefits observed with
other resisted jump training devices on the market.
Due to the lack of biometric data acquired during this study,
physiological explanations for the findings will remain strictly
theoretical. Perhaps such speculation may lead to future
research and improved knowledge in this area. Certainly,
numerous physiological factors influence rate of force devel-
opment and muscular power output, 2 of which include
activation of muscle tissue and synchronization of fiber
recruitment. Recruitment of larger numbers of motor units
and synchronizing their activation would result in much
greater force development in a rapid fashion. Thus, such
adaptations would greatly enhance power output. It is
possible that training on the VMax resulted in greater adap-
tations in such areas. Subsequent research is needed, however,
using EMG measures to verify such a hypothesis.
While strength training and plyometric exercise have been
shown to increase power among athletes, as an individual
becomes more highly trained, the resultant adaptation to
training diminishes. The athletes employed in this study were
very accustomed to conventional sports conditioning meth-
ods as was used by the TCo group. Each athlete had
performed plyometric-type exercises for at least 2 years.
Basketball players and gymnasts in particular are quite
accustomed to performing jumps with only their body
weight as resistance. In such cases, conventional plyometric
exercises are unlikely to provide significant amounts of
overloading stimuli to the neuromuscular system. A unique
quality of the VMax apparatus is in the ability to apply
progressive resistance to plyometric jumps. The added resis-
tance, along with the capacity to alter and progress the resis-
tance over time, may certainly be used to enhance the
stimulation of the neuromuscular system and to elicit
adaptations in the areas of activation and synchronization.
Performance of resisted jump exercises on the VMax has been
shown to have a positive effect on power development among
well-trained collegiate athletes. In an arena where maximal
power adaptations are considered necessary, inclusion of such
training to supplement conventional strength and power
training will result in significantly greater adaptations. Supe-
rior performance enhancement and injury reduction may be
expected with the incorporation of the VMax apparatus over
other alternatives of jump training. The functional mecha-
nisms responsible for these benefits are as a result of the
versatility of movement that the VMax permits and the
unique capacity to exaggerate jump landing/movement
deceleration as well as the unrestricted ability to progressively
overload the training stimulus.
One VertiMax V-6 unit was provided by Genetic Potential for
this research. No other support, financial or other, was
provided by this company nor have the authors received any
compensation related to this research.
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Journal of Strength and Conditioning Research
VertiMax Jump Training
... 2,3 In most instances, the components that contribute to strength and power are trained in a gymbased setting with the goal that the physiological and neuromuscular adaptations from training transfer favorably to match play. 4 Within the context of rugby training, it is important to critically evaluate the relationship between strength and power where the effectiveness of training interventions aimed at the maintenance of performance during the in-season period, remain understudied. ...
... 7,8 One alternative method that has shown promise for developing strength and power in recent years involves the use of resistance bands. 4,[9][10][11] Resistance bands increase load in proportion to band elongation and therefore provide 2 distinct advantages over regular resistance training (RT): (1) greater loads toward the end stage of movement require a longer acceleration period compared with RT and (2) a lower load at the beginning of a given movement implies a lower lifting inertia thereby allowing for greater initial lifting velocities compared with RT. 12,13 More specifically, loaded or resisted jump training is a plyometric-related training method that utilizes the stretch-shortening cycle, which is actuated when the active muscle is stretched rapidly during an eccentrically focused movement and is; therefore, likely to transfer more favorably to the sporting environment due to greater perceived specificity. The effectiveness of resisted jump training is, however, dependent on the load used (ie, resistance of the bands), technique, and effort, 14 as well as instructional focus (ie, verbal cues). ...
Purpose: To determine the effects and transferability of a resisted-jump training program on strength, speed, power, and agility maintenance during the in-season phase of rugby training. Methods: Thirty high-level male rugby players (age: 21.78 [1.86] y; height: 1.83 [0.10] m; mass: 95.17 [10.45] kg) participated in a crossover, within-subject study design. Participants were randomly assigned to treatment groups (resistance band [VertiMax, VM] or control [Con]) and evaluated on jumping, sprinting, agility, and strength over a 4-week period. A 10-week wash-out period was initiated, followed by a crossover that incorporated randomization of the treatment sequence (ie, receiving VM during the first or second phase of the testing period). Within- and between-groups differences for each variable of interest were evaluated using a linear mixed-effects model. Results: No significant treatment (VM vs Con) or time (pre vs postintervention) effects were evident across all variables (all P > .197), although the order or treatment allocation may play a role for strength (P = .037) and jumping (P = .003). Power, agility, and countermovement-jump height were statistically equivalent for the intervention period. Following the VM treatment, changes in strength seem to transfer favorably to changes in agility (r = -.54, P < .05) but no other variables, and no significant associations were evident for the Con treatment. Conclusion: Regardless of treatment, power, agility, and jump height were conserved throughout the treatment period. Although changes in mean sprint and strength were not significantly different from zero, it was not possible to conclude whether performance decrements could be eliminated.
... From the 33 PJT studies conducted with female soccer players, 20 studies mixed female soccer players with athletes from other sports (Arundale, et al., 2018;Brown, et al., 2014;Carlson, et al., 2009;Chappell and Limpisvasti, 2008;Chimera, et al., 2004;E. S. S. de Villarreal, et al., 2011;Elias, et al., 2018;Hewett, et al., 1999;Huang, et al., 2014;Ismail, et al., 2010;Lephart, et al., 2005;Makaruk, et al., 2011;Myer, Ford, Brent, et al., 2006;Myer, Ford, McLean, et al., 2006;Myer, et al., 2005;Pfeiffer, et al., 2006;Rhea, et al., 2008;Staynor, et al., 2017;Ullrich, et al., 2018;Weltin, et al., 2017). In addition, 2 studies mixed female with male soccer players (Faude, et al., 2013;Moore, et al., 2005) and 2 studies did not incorporated a comparative control group Grieco, et al., 2012). ...
... Through database searching, 7,136 records were initially identified, and 33 PJT studies included female soccer players(Arundale, Capin, Zarzycki, Smith, & Snyder-Mackler, 2018;Brown, Palmieri-Smith, & McLean, 2014;Carlson, Magnusen, & Walters, 2009;Chappell and Limpisvasti, 2008;Chimera, Swanik, Swanik, & Straub, 2004; E. S. Villarreal, Izquierdo, & Gonzalez-Badillo, 2011;Elias, Harris, LaStayo, & Mizner, 2018;Faude, Roth, Giovine, Zahner, & Donath, 2013;Greska, Cortes, Van Lunen, & Oñate, 2012;Grieco, Cortes, Greska, Lucci, & Onate, 2012;Hewett, Lindenfeld, Riccobene, & Noyes, 1999;Huang, Chen, Lin, & Lee, 2014;Ismail, Ibrahim, Youssef, & El Shorbagy, 2010;Lephart et al., 2005;Makaruk, Winchester, Sadowski, Czaplicki, & Sacewicz, 2011;Moore, Hickey, & Reiser Ii, 2005;Myer, Ford, Brent, & Hewett, 2006;Myer, Ford, McLean, & Hewett, 2006;Myer, Ford, Palumbo, & Hewett, 2005;Ozbar, Ates, & Agopyan, 2014;Pfeiffer, Shea, Roberts, Grandstrand, & Bond, 2006; Ramirez-Campillo,Garcia-Pinillos, et al., 2018;Ramirez-Campillo, Gonzalez-Jurado, et al., 2016;Ramirez-Campillo, Vergara-Pedreros, et al., 2016;Rhea, Peterson, Oliverson, Ayllon, & Potenziano, ...
To assess the effects of plyometric jump training (PJT) in female soccer player’s vertical jump height, a review was conducted using the data sources PubMed, MEDLINE, Web Of Science, and SCOPUS. Only peer-review articles were included. To qualify for inclusion in the meta-analysis, studies must have included i) a PJT programme of at least 2 weeks, ii) cohorts of healthy female soccer players with no restriction for age, iii) a control group, iv) a measure of countermovement jump (CMJ). The inverse variance random-effects model for meta-analyses was used. From 7,136 records initially identified through database searching, 8 were eligible for meta-analysis, comprising 9 training groups (n=99) and 9 control groups (n=94). The magnitude of the main effect was moderate (ES = 1.01 [95%CI = 0.36-1.66], Z = 3.04, p = 0.002). Sub-group analyses were performed (i.e., PJT frequency, duration, and total number of sessions), revealing no significant subgroup differences (p = 0.34 - 0.96). Among the studies included in this review, none reported injury or other adverse effects. In conclusion, PJT is effective in female soccer players for the improvement of vertical jump height. In future, research must identify specific dose-response relationships following PJT, particularly in the long term.
... Similar magnitude improvements in jump performance and power may be expected given the wellestablished relationship between the two factors [30][31][32][33]. In addition, many of the studies measured power during loaded and unloaded jumps, further increasing associations and similar magnitude improvements. ...
... By organizing the training process on a scientific basis, the knowledge of biomechanics aspects in competitions and training is obtained to reduce injuries [76]. In this sense, the biomechanical diagnosis is identified, using the force-time curve for different movements [77]. In team sports, the relationship between workload and the possibility of soft tissue injuries was investigated using handheld global positioning system (GPS) technology. ...
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Background: Research on the application of technology in sports in Romania is completely lacking, and the existing studies at the international level have mainly been carried out in recent years. We considered it appropriate to highlight the best practice models of technology application in sports that can be multiplied, adapted, improved, and widely used. The paper aims to identify the use of technology and devices in sports, with an emphasis on their role in training and competitions with the aim of improving sports performance, to provide sports specialists, organizations, and authorities with a wide range of information regarding the connection between sport and technology. The results obtained regarding the application of technology in sports refer mainly to the following: techniques and technologies used in training and competition (portable localization technology and global positioning systems (GPS); Virtual Reality (VR) technology; video analysis; digital technologies integrated into sports training); aspects of sports training targeted through the use of technology (use of technology for athlete health, recovery, and injury management; use of technology for monitoring sports performance and various body indicators); training optimization and ecological dynamics and the sustainable development of sports. Conclusions: Unitary research, at a European or even global level, in a uniform theoretical and practical framework, could lead to much more efficient training with large increases in sports performance. The coaches and specialists working with the athlete determine the specificity of some elements of the training, depending on the characteristics of each athlete. Large clubs could become a factor in generating and disseminating knowledge related to training and competition monitoring, sports performance enhancement, and health, recovery, and injury management. Research directions for the use of technology in sport and the formation of connections with other fields can be extended. For example, combined technologies assisted by specialized software can be used. Creativity must be the starting point for the use and combination of existing technologies in sports and for the creation of new ones. Their creation and use involve the teamwork of athletes, coaches, and specialists from different fields, such as sports, physiology, psychology, biomechanics, informatics, etc.
... Además los autores de estos estudios entienden que sumar EMI más ejercicio dinámico es incluir otro tipo de entrenamiento de fuerza complementario, como puede ser el entrenamiento pliométrico, o un entrenamiento tradicional con pesas, ejecutado a continuación del entrenamiento con EMI (Rhea, et al., 2008b;Willoughby, & Simpson, 1996;Maffiuletti, Dugnani, Folz, Di Pierno, & Mauro, 2002); y no a la realización de ambos estímulos de manera simultánea, tal y como hacemos en el presente trabajo. ...
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RESUMEN El objetivo del presente estudio fue analizar los cambios en el rendimiento en función de dos métodos de entrenamiento, el desarrollado mediante electro-estimulación muscular integral (EMI) frente a otro en el que se utilizaron bandas elásticas y que denominamos entrenamiento funcional con elásticos (EFE). La muestra estuvo compuesta por un grupo de diez (N=10) personas físicamente activas (23,04 ± 2,5 años). Se utilizó un diseño cuasi-experimental con medidas pre-post. Y fueron analizados los resultados de las pruebas: salto vertical con ayuda de brazos; y velocidad de desplazamiento en una carrera de ida y vuelta de 12 metros de distancia (6+6). Se realizó un análisis descriptivo de casos y medias. Y dado el tamaño de la muestra se calculó el tamaño del efecto, el cual fue bajo o moderado (d<0,5). Por último se compararon las diferencias de las medias de los grupos mediante la U de Mann Whitney, y las diferencias de las medias en función del tiempo (pre-post) mediante Friedman; en ambos casos los resultados no fueron significativos (p<0,5). En cuanto a los valores descriptivos del pre-post en ambos grupos: el grupo que entrenó con bandas elásticas obtuvo mejores resultados en ambas pruebas que el grupo que entrenó con EMI. En conclusión, el entrenamiento con bandas elásticas, a pesar de no ser significativo, parece mostrarse más efectivo que el entrenamiento con electro-estimulación muscular integral. Si bien, dadas las limitaciones del estudio estos datos hay que tomarlos con la pertinente cautela. Palabras clave: Electro-estimulación integral, entrenamiento funcional con bandas elásticas.
... In previous studies, effects of environmental constraints such as footwear (Lesinski et al., 2018) and ground surface (Leporace et al., 2013;Lesinski et al., 2018) on CMJ performance are studied. In addition, effects of task constraints such as extra load (Macadam et al., 2017;Moreau, 2016;Swinton et al., 2012) and resistant force (Aboodarda et al., 2013;Loturco et al., 2015;Rhea et al., 2008) are also studied. The implementation of extra load and resistant force could be considered as an alternation to physical abilities of the performer to overcome those forces and consequently manipulate the organism constraints. ...
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In previous studies, the acute effects of movement constraints on the countermovement jump performance are investigated; however, the longitudinal effects of implementing the constraint in a training regimen are not well studied. The purpose of this study was to examine the phenomenon of motor learning development due to application of task constraint in a training regimen following 6 weeks of training. Forty-five healthy adult males were randomly assigned to a control or one of two experimental constraint training groups (i.e., no arm swing or restricted knee flexion). Pre- and posttraining jump height and kinematic variables of six maximum effort countermovement jumps were compared longitudinally within the groups, and also compared between the groups. The findings of this study indicated that jump height significantly increased in all the groups while in the unrestricted control group it was increased greater than the experimental conditions (21% compared with 12% and 5.5%). However, the applied task constraints significantly improved some of the contributors to jump performance, establishing specific adaptation of kinematic variables to the constraint training. Therefore, constraint training approach could be suggested in case of demanding specific adaptation of kinematic variables of countermovement jump in a training regimen.
... Unfortunately, if EBM remains problem oriented the ability to research prevention, performance enhancement and quality of life upgrades with remain mostly without peer review [33,34,[48][49][50][51][52][53][54][55]. ...
Experiment Findings
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Foundational Stability, Support, Strength, Symmetry and Balance of the Foot and Lower Extremity is the Predictable Primary Starting Platform for All Closed Chain Stance and Movement
... Implementation of technical and tactical trainings within the game and in positions, that change instantly, is a major factor in improvement of properties such as coordination and reaction. The fact that athletes reflect the physical, psychological and other impacts of trainings on their skills is essential for their optimal functions, success, and prevention of injuries (Rhea et al., 2008). Today, there are many studies performed by experts that can develop and improve the physical fitness parameters of athletes in order to increase their success (Harris et al., 2000). ...
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This study was carried out in order to compare certain physical fitness parameters of young basketball and football players. Basketball players, who are playing in U16 league (n=12), and football players playing in U17 league (n=10) participated in the study voluntarily. Groups were separated into two as the basketball group (BG) and the football group (FG). BG has a body weight mean of 74.13±7.26 kg, a height mean of 187.50±7.03 cm, and an age mean of 16. FG has a body weight mean of 68.0±7.95 kg, a height mean of 178.4±5.31 cm, and an age mean of 17. Participants were applied performance tests, which are composed of sit and reach test, leg strength, hand grip strength, flexibility, 20 m sprint, and flamingo balance test among physical fitness parameters. Data obtained were analysed using SPSS 19.0 package program, and Mann Whitney U test was used to compare two groups. While there was no meaningful difference between strength and flexibility values (p>0.05), a meaningful difference occurred in favour of FG in 20 m speed test (p<0.05). As a result, the difference that occurred in speed only makes us think that height and body weight in basketball players can impact speed and agility negatively compared to football players.
... Por ejemplo, existe un sistema de poleas de entrenamiento para los miembros inferiores y superiores denominado Vertimax, el cual provee un entrenamiento de potencia y resistencia a través de la aplicación de cargas mediada por poleas y bandas elásticas. (McClenton, Brown, Coburn, & Kersey, 2008;Rhea, Peterson, Lunt, & Ayllón, 2008;Rhea, Peterson, Oliverson, Ayllón, & Potenziano, 2008) Otro sistema tecnológico es el Optogait, es un sistema de obtención de datos sobre la marcha y la carrera basada en bandas trasmisoras y receptoras, este sistema permite determinar con exactitud parámetros temporoespaciales de la marcha como: longitud de paso, cadencia, ancho de paso, fuerza de presión, velocidad de la carrera. (Mo Lee, y otros, 2014;Lienhard, Schneider, & Maffiuletti, 2013) Existe también un sistema conocido como HUMAC caracterizado por ser un sistema confiable para la medición de fuerza isocinética en deportistas. ...
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Introducción: en la última década la tecnología ha avanzado en muchos campos profesionales alrededor del mundo, en fisioterapia el uso de la tecnología ha tenido un aumento exponencial en la creación de dispositivos tecnológicos de intervención y evaluación fisioterapéutica en pacientes con diversas patologías. Objetivo: realizar una revisión de la literatura con relación a las nuevas tecnologías de intervención y evaluación en fisioterapia. Materiales y métodos: se realizó una búsqueda de estudios entre el año 2000 y 2016, literatura que contemplara los siguientes términos MESH: Technology, Sport, Physical Theraphy, Virtual rehabilitation, Medical Laboratory. Resultados: las nuevas tecnologías en fisioterapia son sistemas especializados en la rehabilitación de pacientes con patologías neurológicas, osteomusculares y cardiovasculares, entre los sistemas a nivel mundial más conocidos se encuentran: balance trainer, dynstable, aretech zerog, zerog overground, Xbox Kinect, exoesqueletos robóticos, vetimax, optogait, humac, cold system, chaleco de electroestimulación, virtual rehab, Pablo, Nirvana, sistema BTS y sistemas de medición antropométrica. Conclusiones: la tecnología es la base del futuro, en rehabilitación el desarrollo de nuevos dispositivos permitirá la creación de nuevas herramientas de intervención lo cual favorecerá el crecimiento de nuevos conceptos en la fisioterapia a nivel mundial.
Objectives Watson-Jones proximal tibial avulsion injuries occur more frequently in athletic and muscular adolescent males. However, they are rare and therefore infrequently described in the medical literature. Two of these injuries occurred in a Category 1 football academy in the same season within a six-month period. We have described the cases with the hope of better informing other clinicians should they encounter this injury. Methods This case report describes the injury mechanism, surgical management and rehabilitation for the two cases [Players A and B]. Outcomes measures including player speed, agility and power were compared with scores from players of the same age group at the time of injury in the Premier League academies. Risk factors are also discussed. Results Both players were managed surgically, initially. Player B had the surgical fixation removed during rehabilitation. Player A still has the fixation in situ. Post-surgery, player A returned to full play at thirty-two weeks and thirty-eight weeks for player B. No critical incidents occurred during rehabilitation. Conclusion Watson-Jones avulsion fractures, although rare, can be managed successfully. Athletes can achieve a successful return to play at their previous level.
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This study examined the relative effectiveness of two leading forms of athletic training in enhancing dynamic performance in various tests. Thirty-three men who participated in various regional level sports, but who had not previously performed resistance training, were randomly assigned to either a maximal power training program, a combined weight and plyometric program, or a nontraining control group. The maximal power group performed weighted jump squats and bench press throws using a load that maximized the power output of the exercise. The combined group underwent traditional heavy weight training in the form of squats, and bench press and plyometric training in the form of depth jumps and medicine ball throws. The training consisted of 2 sessions a week for 8 weeks. Both training groups were equally effective in enhancing a variety of performance measures such as jumping, cycling, throwing, and lifting. (C) 1996 National Strength and Conditioning Association
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Explosive leg power is a key ingredient to maximizing vertical jump performance. In training, the athlete must use the most effective program to optimize leg power development. The purpose of this study was to compare the effectiveness of three training programs - squat (S), plyometric (P) and squat-plyometric (SP) - in increasing hip and thigh power production as measured by vertical jump. Forty-eight subjects were divided equally into four groups: S, P, SP or control (C). The subjects trained two days a week for a total of seven weeks, which consisted of a one-week technique learning period followed by a six- week periodized S, P or SP training program. Hip and thigh power were tested before and after training using the vertical jump test, and the alpha level was set at 0.05. Statistical analysis of the data revealed a significant increase in hip and thigh power production, as measured by vertical jump, within all three treatment groups. The SP group achieved a statistically greater improvement (p < 0.0001) than the S or P groups alone. Examination of the mean scores shows that the S group increased 3.30 centimeters in vertical jump, the P group increased 3.81 centimeters and the SP group increased 10.67 centimeters. The results indicate that both S and P training are necessary for improving hip and thigh power production as measured by vertical jumping ability. (C) 1992 National Strength and Conditioning Association
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The purpose of this study was to determine whether ballistic resistance training would increase the vertical jump (VJ) performance of already highly trained jump athletes. Sixteen male volleyball players from a NCAA Division I team participated in the study. A Vertec was used to measure standing vertical jump and reach (SJR) and jump and reach from a three-step approach (AJR). Several types of vertical jump tests were also performed on a Plyometric Power System and a forceplate to measure force, velocity, and power production during vertical jumping. The subjects completed the tests and were then randomly divided into two groups, control and treatment. All subjects completed the usual preseason volleyball on-court training combined with a resistance training program. In addition, the treatment group completed 8 wk of squat jump training while the control group completed squat and leg press exercises at a 6RM load. Both groups were retested at the completion of the training period. The treatment group produced a significant increase in both SJR and AJR of 5.9+/-3.1% and 6.3+/-5.1%. respectively. These increases were significantly greater than the pre- to postchanges produced by the control group, which were not significant for either jump. Analysis of the data from the various other jump tests suggested increased overall force output during jumping, and in particular increased rate of force development were the main contributors to the increased jump height. These results lend support to the effectiveness of ballistic resistance training for improving vertical jump performance in elite jump athletes.
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Ten active males performed reactive drop jumps from a height of 40 cm in six experimental conditions: jumps with additional loads of 100 N (BW+ 100 N) and 200 N (BW+ 200 N), an ordinary jump with body weight (BW) and three jumps in which the body weight was artificially reduced (BW-172 N, BW-337 N and BW-495 N). The vertical ground reaction forces, the angular displacement in the knee and ankle joints as well as the surface electromyogram (EMGs) of the triceps surae muscles and tibialis ant. muscle were recorded. When compared to the control condition (BW) in the jumps with extra load and in the jumps with reduced body weight, both the take-off velocity as well as the mean vertical ground reaction force were decreased during the push-off phase. The integrated EMG before ground contact as well as the duration of the preactivation phase was significantly reduced as a function of the load condition. Upon the touchdown, the coactivation of the muscles acting around the ankle joint was greatest in the control jump. Through all experimental conditions, the mean activation amplitude remained rather constant both for the impact as well as for the push-off phase of the contact. It is concluded that the centrally programmed activity prior to the contact can be seen as the decisive mechanism in the regulation of the stiffness behavior of the tendomuscular system. The extent of the preprogrammed activity determines mainly the physical output of the entire jump exercise.
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The influence of series elastic structures on the dynamics of the contractile machinery was examined in the gastrocnemius medialis (GM) of five male Wistar rats, with respect to enhancement of work of a muscle-tendon complex after active stretch. Imposed isotonic and isokinetic contractions were preceded by either an isometric phase (PI) or an active stretch (PS). The effects of fibre length differences at the onset of shortening, due to differences of extension of tendinous structures, were studied. For the isotonic experiments fibre length and shortening velocity were estimated 30 ms after release and compared with the PI length velocity curve determined at the same force level. For shortening above the optimum length, about half of the enhanced shortening found after prestretch could be explained by PS—PI fibre length differences. Below the optimum length, PS shortening velocity was somewhat lower than expected on the basis of length-velocity characteristics. Enhancement of work output due to stretch was different for isokinetic and isotonic shortening. In isokinetic shortening, following prestretch, fibre work was limited because of enhanced shortening of the tendinous structures. In stretch-shortening cycles imposed on a muscle-tendon complex, the length of the complex affected all prestretch effects, i.e. potentiation of the contractile element, contractile element interaction with the tendinous structures, and elastic energy release. It is concluded that, besides potentiation effects and enhanced elastic energy release, the influence of series elastic structures on fibre dynamics determines active stretch-induced work enhancement. The contribution by these mechanisms to this work enhancement depends largely on the type of stretch-shortening cycle.
Some controversy exists concerning the "transfer of training effect" from different methods of resistance-training programs to various athletic performance variables. The purpose of this study was to examine the effects of 3 different resistance-training methods on a variety of performance variables representing different portions of the force velocity curve, ranging from high force to high speed movements. Forty-two previously trained men (1 repetition maximum [RM] squat kg per kg body mass >= 1.4) served as subjects. After a 4-week high-volume training period and the pretests, the subjects were randomly assigned to 1 of 3 groups. The groups were high force (HF; n = 13), high power (HP; n = 16), and a combination training group (COM; n = 13); each group trained 4 d[middle dot]wk-1 for 9 weeks. Group HF trained using 80-85% of their 1RM values. Group HP trained at relative intensities approximating 30% of peak isometric force. Group COM used a combination training protocol. Variables measured pre-and posttraining were the 1RM parallel squat, 1RM 1/4 squat, 1RM midthigh pull, vertical jump (VJ), vertical jump power, Margaria-Kalamen power test (MK), 30-m sprint, 10-yd shuttle run (10-yd), and standing long jump (SLJ). Data were analyzed within groups with t-tests, and the between-group analysis used a group [chi] trials analysis of variance test. The HF group improved significantly in 4 variables (p <= 0.05 for squat, 1/4 squat, midthigh pull, MK), the HP group in 5 variables (p <= 0.05 for 1/4 squat, midthigh pull, VJ, MK, SLJ), and the COM group in 7 variables (p <= 0.05 for squat, 1/4 squat, midthigh pull, VJ, VJP, 10-yd). These results indicate that when considering the improvement of a wide variety of athletic performance variables requiring strength, power, and speed, combination training produces superior results. (C) 2000 National Strength and Conditioning Association
Effects of power training with stretch-shortening cycle (SSC) exercises on mechanical efficiency (ME) were investigated with 9 young women who trained 3 times a week for 4 months. The training included various types of jumping exercises. Before and after the training as well as after the detraining (2 months) the subjects performed 6 different submaximal exercises with a special sledge apparatus. Each exercise involved 60 muscle actions lasting for a total of 3 min per testing condition. The work intensities were determined individually according to the recordings of distance obtained during the single maximal concentric exercises. The training caused the greatest changes of ME in conditions of higher prestretch intensities. The ME values changed from 49.3 ± 12.9% to 55.4 ± 12.1% in pure eccentric exercises and from 39.5 ± 4.6% to 46.1 ± 5.0% in SSC exercises during the training. After the training, the subjects preactivated their leg extensor muscles earlier before the impact, and the eccentric working phase was more powerful, because of higher tendomuscular stiffness. Higher preactivation of the measured muscles, higher flexion of knee and increased dorsiflexion of ankle joints in the beginning of contact caused the increased stiffness, possibly through more powerful reflex activation. At the same time the metabolic demands of muscles decreased, causing the increases of ME.
Mechanical efficiency of positive work (eta+) and elastic behavior of human skeletal muscles were investigated on a special sledge apparatus which allowed the use of the normal stretch-shortening cycle exercises. Twenty-five young men were investigated in a total of 92 exercise situations, in which the intensity of the prestretch (eccentric contraction) was different, but the shortening phase (concentric contraction) was kept constant in all conditions. The results demonstrated that eta+ was on the average 35.8% +/- 6.4% and correlated positively with the prestretch intensity (r = 0.413; P less than 0.001), reaching a highest individual value of 51.5%. Estimation performed on the elastic characteristics of the leg extensor muscles confirmed an earlier suggestion that the pure muscle elasticity plays an important role in potentiating performance in stretch-shortening cycle exercises. The analysis of the myoelectrical activity of the leg extensor muscles showed that the nervous system plays an essential role in regulating muscle stiffness and thus utilization of muscle elasticity in ballistic exercises.