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ORIGINAL ART I C L E
Effects of in-season short-term plyometric training on jumping
and agility performance of basketball players
Abbas Asadi
Received: 16 June 2013 / Accepted: 11 October 2013 / Published online: 29 October 2013
ÓSpringer-Verlag Italia 2013
Abstract The purpose of this investigation was to
examine the effects of in-season plyometric training pro-
gram on power and agility performance in young male
basketball players. Twenty intermediate basketball players
(age 20.1 ±1.3 years; height 181.1 ±8.5 cm; body mass
78.8 ±5 kg) from Division I province team volunteered to
participate in this study and were randomly divided into
two groups: plyometric training (PL; n=10) and control
group (CG; n=10). Plyometric training took place twice
weekly for 6 weeks including three sets of 15 repetitions of
depth jump (from 45-cm box height), vertical jump, and
standing long jump, in addition to regular basketball
practice of the team. Vertical jump (VJ), standing long
jump (SLJ), 4 99-m shuttle run, agility ttest (ATT),
and Illinois Agility Test (IAT) were measured at pre-
and post-training. The PL group showed significant
improvement (P\0.05) in VJ (10.21 ±2.72 cm), SLJ
(21.15 ±8.10 cm), 4 99-m shuttle run (0.62 ±0.28 s),
ATT (1.16 ±0.57 s), and IAT (1.17 ±0.65 s) after a
6-week training period and compared to CG. It can be
concluded that a 6-week in-season plyometric training
program has positive effects for improving power and
agility performance in young male basketball players and
this study provides support for coaches and basketball
players who use this training method during competitive
phase.
Keywords Agility Plyometric exercise Jump
Basketball
Introduction
In basketball, the ability to generate maximal strength
levels in the shortest period of time (muscular power) is
necessary to gain high sport performance levels [1].
Moreover, agility is a vital component for the success in
basketball players [2]. Two methods, plyometric and
resistance training, are usually referred to in the literature
as improving the most powerful strength characteristics
(explosive strength) in basketball players. Several studies
have demonstrated the positive effects of plyometric and
resistance training to increase the levels of strength and
power [3,4].
Plyometric exercise, such as jumping, bounding, and
hopping, is a widely used training mode to improve muscle
power [5]. Plyometrics consists of a rapid stretching of a
muscle (eccentric phase) immediately followed by a con-
centric or shortening action of the same muscle and con-
nective tissue, and this phenomenon is called stretch–
shortening cycle [5]. Plyometric training has been shown to
improve jumping ability [4], agility [6], running economy
[7], and strength [8].
However, a large number of studies investigated the
effects of plyometric training efficacy on performance [2,
3,6,8–14]; only one study examined the effects of in-
season plyometric training in basketball players [11].
Therefore, the purpose of the present study was to examine
the effects of a 6-week in-season plyometric training pro-
gram on muscular power and agility performance in young
male basketball players.
A. Asadi (&)
Department of Physical Education and Sport Sciences, Payame
Noor University, Tehran, P.O. Box 19395-3697, Islamic
Republic of Iran
e-mail: abbas_asadi1175@yahoo.com
123
Sport Sci Health (2013) 9:133–137
DOI 10.1007/s11332-013-0159-4
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Materials and methods
Participants
Twenty young basketball players volunteered to participate
in this study and were randomly assigned to plyometric
group (PL; n=10; age 20.2 ±1 years; height
182.1 ±9.2 cm; and body mass 78.5 ±5.5 kg) and con-
trol group (CG; n=10; age 20.1 ±1.5 years; height
180.1 ±7.2 cm; and body mass 79.5 ±4.5 kg). The par-
ticipants were Division I province team and trained tech-
nical and tactical basketball practice three sessions a week
for 90 min. The participants were healthy, free from any
lower body injuries and they had no medical and ortho-
pedic problems. Before data collection, the participants
were informed about the benefit and possible risk associ-
ated with the study and provided written informed consent.
The research project was conducted in accordance with the
Declaration of Helsinki and was approved by the Univer-
sity Review Board for use of Human Subjects.
Plyometric training and design
Plyometric training program was performed twice weekly
for 6 weeks (on Monday and Friday). The intensity and
volume of plyometric training was based on recommen-
dations of Chu [5] and Stemm and Jacobson [15]. Partici-
pants in the PL group trained depth jump (from 45-cm box
height), vertical jump, and standing long jump, respec-
tively. The training protocol consisted of three sets of
15-reps separated by a 2-min rest for each exercise. Plyo-
metric training sessions were added with regular basketball
practice and lasted 55 min, and began with a standard
10-min warm-up, including 5-min jogging, 5-min ballistic
exercises and stretching; 40-min main training, and 5-min
cool down. Subjects in PL group were instructed to per-
form exercises in each training session with maximal
effort. During the intervention of 6 weeks, PL and CG
continued their normal basketball training, and were not
allowed to perform any other training (such as: resistance
training and or plyometric training) that would impact the
results. A week pre- and post-training period, vertical jump
(VJ), standing long jump (SLJ), 4 99-m shuttle run,
agility ttest (ATT), and Illinois Agility Test (IAT) were
measured.
Dependent variables
To evaluate the effects of plyometric training on agility,
and power, five tests including VJ, SLJ, 4 99-m shuttle
run, ATT, and IAT were measured, respectively. Before
initial testing, each player was familiarized with the testing
protocol. To standardize testing procedures, the same
trained test leaders carried out the entire test procedure
using identical order and protocol. Before testing, subjects
performed 10-min warm-up protocol consisting of sub-
maximal jogging, and active stretching. There was a 5-min
rest in between tests to ensure recovery.
Vertical jump
The vertical jump (VJ) was assessed using Vertec (Power
Systems, Knoxville, TN 22550, USA). The Vertec was
adjusted to match the height of the individual subject by
having him stand with the dominant side to the base of the
testing device. The dominant hand was raised and the
Vertec was adjusted so that the hand was the appropriate
distance away from the marker based on markings on the
device itself. On verbal ‘‘GO’’ command, the volunteers
flexed their knee joints (*90°) and jumped as high as
possible. The difference between initial value and maximal
jump height value was calculated to determine VJ height.
Each test was performed twice, and the best value of the
two measurements was used for the analysis [13,14].
Standing long jump
The standing long jump was used as a test of bilateral leg
power. Arm movements were permitted for support during
the take-off movements. Trials were only evaluated when
the subjects landed properly on their feet while not falling
back. The distance between the toes at start and the heels at
landing was used as a testing criterion. The best of the two
SLJs was used for the statistical analysis [16].
499-m shuttle run
The shuttle run test was included as a measure of the ability
to sprint and change direction. With the 4 99-m shuttle
run, the subjects stood behind the starting line and on
command, they started the 9-m run. At the end of the 9-m
section, the subjects were asked to stop with one foot
beyond a marker, while reversing the running direction and
sprinting back to the start where the same reversing of
movement direction was required. After the fourth 9-m
section, when the subjects crossed the finish line, the time
was stopped. A hand-held stopwatch was used to measure
the sprint time to the nearest 0.01 s (Joerex, ST4610-2,
China). The best value of two consecutive trials was used
for the statistical analysis. Three minutes rest between
attempts was provided for each subject [16].
Agility ttest
Subjects’ agility was evaluated using the ATT according to
the method of Miller et al. [6]. The ttest was performed on
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the basketball court. A hand-held stopwatch was used to
take the subjects’ time to the nearest 0.01 s. The subjects
were instructed to sprint from a standing starting position
to a cone 10 m away, followed by a side-shuffle left to a
cone 5 m away. After touching the cone, the subjects side-
shuffled to the cone 10 m away and then side-shuffled back
to the middle cone. The test was concluded by back-ped-
aling to the starting line. The test score was recorded as the
best time of three trials, to the nearest 0.01 s. A 5-min rest
period was allowed between each trial [2].
Illinois agility test
The subjects’ agility was assessed using the IAT according
to the method of Miller et al. [6]. A hand-held stopwatch
was used to take the subjects’ time to the nearest 0.01 s.
The run started with a standing start on the command
‘‘GO’’ and subjects sprinted 10 m, turned, and returned to
the starting line. When the subjects reached the starting
line, they zigzagged in between four markers and com-
pleted two 10 m sprints. The fastest time of the three trials
was noted as the final agility time. A 5-min rest period was
allowed between each trial [2].
Statistical procedures
All data are presented as mean ±SD. A 2 92 analysis of
variance (ANOVA) was used to determine significant dif-
ferences between groups. When a significant Fratio was
found, Tukey post hoc tests were used for pairwise com-
parisons. A criterion alevel of PB0.05 was used to
determine statistical significance. All statistical analyses
were performed through the use of a statistical software
package (SPSS
Ò
, Version 16.0, SPSS., Chicago, IL).
Results
No injuries occurred throughout the study period, and the
testing and training procedures were well tolerated by the
subjects.
There were no significant differences between PL and
CG at pre-training. After 6 weeks of training, the PL group
made significant (P\0.05) improvements in VJ (from
41.31 ±3.40 to 51.25 ±2.11 cm; 24.1 %), SLJ
(214.82 ±9.20 to 235.11 ±8.42 cm; 9.4 %), 4 99-m
shuttle run (from 9.65 ±0.31 to 9.01 ±0.24 s; 6.7 %),
ATT (from 12.01 ±0.56 to 10.97 ±0.61 s; 8.6 %), and
IAT (from 17.36 ±0.48 to 16.14 ±0.51 s; 7.1 %) per-
formance in comparison to pre-training and CG. Jump test
(VJ and SLJ) results are presented in Fig. 1, while agility
(4 99-m shuttle run, ATT, and IAT) evaluations are
reported in Table 1.
Discussion
We tested that whether 6 weeks of in-season plyometric
training would lead to improvement in performance in
young male basketball players. It was observed that ath-
letes who added plyometric training to their regular bas-
ketball practice were able to achieve improvements in
lower body power and agility when compared with subjects
who participated in a basketball practice without plyo-
metric training.
In the present study, the plyometric training group
increased VJ and SLJ (24.1 and 9.4 %, respectively),
whereas control group showed no improvement. Many
studies indicated significant improvements in VJ following
plyometric training program [12–17], especially in bas-
ketball players [2–4,9–11]. In basketball players, some
studies examined the effect of plyometric training program
on VJ performance. For example, Brown et al. [3] exam-
ined the influence of three sets of ten drop jumps three
times weekly for 6 weeks and found 11.1 % increases in
VJ following plyometric training. Also, Matavulj et al. [4]
compared two groups of basketball players. One group
performed drop jumps from a 50-cm box height and
another group performed drop jumps from a 100-cm box
height. Both groups demonstrated significant increases in
VJ height (12.4 %). In this study, we found that in-season
plyometric exercise (such as depth jump, vertical jump, and
standing long jump) at two times a week for 6 weeks can
increase 24.1 and 9.4 % VJ and SLJ, respectively.
Although, previous authors addressed positive effects of
Fig. 1 Changes in vertical jump and standing long jump at pre- and
post-training. Values are mean ±SD. *Significantly different
(PB0.05) from all other conditions
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different types of plyometric exercise such as sagittal and
frontal plane and added load during plyometric exercise on
jump performance [2,8–10], a few studies examined in-
season plyometric training on muscular performance in
basketball players [11]. In accordance with our findings,
Santos and Janeira [11] found that 10-week in-season
plyometric training could improve explosive power in
adolescent basketball players. The improvement in jump
height indicates that adaptations relating to increases in leg
power have occurred. The adaptations of training are likely
to be neural because these predominate in the early stages
of strength and power training [18] and have been shown to
be the main adaptation to plyometric exercise [19]. Many
authors suggested that muscular performance gains after
plyometric training are attributed to a neural adaptation
located in the nervous system [20,21]. With regard to these
authors, neuromuscular factors such as increasing the
degree of muscle coordination and maximizing the ability
to use the muscles’ stretch–shortening cycle appear to be
more important for the improvement in jump performance
(VJ and SLJ) following high-intense plyometric training
[20,21].
The unique findings of the present study are positive
effects of in-season plyometric training on agility perfor-
mance (4 99-m shuttle run 6.7 %, ttest 8.6 %, and Illi-
nois agility test 7.1 %) in basketball players. These results
are in line with previous researchers who found increases
in quickness and agility via plyometric training [2,6]. In a
study of tennis players, the authors used a ttest and dot
drill test to determine speed and agility [22]. They found
that the players became quicker and more agile; enabling
them to get to more balls and be more effective tennis
players. Renfro [23] measured agility using the ttest with
plyometric training, while Robinson and Owens [24] used
vertical, lateral, and horizontal plyometric jumps and
showed improvements in agility. Miller et al. [6] also
examined the effects of a 6-week plyometrics on agility.
They used PL and control groups, and found significant
differences in PL after training, but no significant
differences between groups in the agility tests (ttest and
Illinois agility test). They reported 4.9 and 2.9 %
improvements in ttest and Illinois agility test, respectively,
but we found higher than 7 % improvement. The difference
in percentage of improvements could be discrepancy in
training intensity and fitness level of participants or train-
ing status [16]. Perhaps trained subjects gain greater
increase in agility performance with regard to their back-
ground and familiarization with training. These findings
demonstrated the necessity of plyometric training program
for enhancing performance in activities which involve
acceleration, deceleration, and a change of direction. In
addition, the plyometric training program may improve the
eccentric strength of the lower limb and resulting increases
in agility performance [25]. It has been well documented
that agility requires development of muscle factors (e.g.,
strength and power) to improve change of direction and it
appears that, agility has high relationship with strength and
power [25]. Perhaps increases in the power performance
became one of the important variables for the enhancement
of agility. Also, neural adaptations and enhancement of
motor unit recruitment are other mechanisms which can
lead to increase in agility tests [6]. However, we could not
exactly determine that neural adaptations occurred or better
facilitation of neural impulse to spinal cord; therefore,
further studies are necessary to determine mechanisms of
agility improvement by plyometric training. Also, future
study should use subjects with differing training status for
determining muscular performance responses to plyometric
training.
In conclusion, the result of this study highlights the
potential of using in-season plyometric training to improve
power and agility, especially in young male basketball
players (19–20 years old). It is recommended that, coaches
design plyometrics in competitive phase for young athletes,
because this type of training can be an effective method for
improving performance. Since coaches and athletes are often
restricted to a short preseason, this is beneficial for coaches
or athletes during collegiate or logical competitions.
Table 1 Agility performance at pre- and post-training
Variable Group Pre-training Post-training % changes
499-m shuttle run Plyometric 9.65 ±0.31 9.01 ±0.24* 6
Control 10.02 ±0.35 10.14 ±0.24 -1
Agility ttest Plyometric 12 ±0.56 10.97 ±0.61* 8
Control 12.15 ±0.57 12.57 ±0.68 -3
Illinois agility test Plyometric 17.36 ±0.48 16.14 ±0.5* 7
Control 17.48 ±0.6 17.41 ±0.49 0.4
Data are presented as the mean ±SD
* Significantly different (PB0.05) from all other conditions
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Acknowledgments The authors would like to thank all the partic-
ipants for their cooperation in this study.
Conflict of interest None.
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