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470
Journal of Strength and Conditioning Research, 2000, 14(4), 470–476
q2000 National Strength & Conditioning Association
Evaluation of Plyometric Exercise Training,
Weight Training, and Their Combination on
Vertical Jumping Performance and Leg Strength
IOANNIS G. FATOUROS,
1
ATHANASIOS Z. JAMURTAS,
2
D. LEONTSINI,
1
KYRIAKOS TAXILDARIS,
1
N. AGGELOUS IS,
1
N. KOSTOPOULOS,
4
AND
PHILIP BUCKENMEYER
3
1
Department of Physical Education and Sport Sciences, Democritus University of Thrace, Komotini, 691 00,
Greece;
2
Department of Exercise and Sports Sciences, The University of North Carolina at Greensboro,
Greensboro, North Carolina 27412;
3
Department of Physical and Health Education, University of Akron, Akron,
Ohio 44325;
4
Department of Physical Education and Sports Science, University of Athens, Athens, 17237, Greece.
ABSTRACT
The purpose of this study was to compare the effects of 3
different training protocols—plyometric training, weight
training, and their combination—on selected parameters of
vertical jump performance and leg strength. Forty-one men
were randomly assigned to 1 of 4 groups: plyometric train-
ing (n511), weight training (n510), plyometric plus
weight training (n510), and control (n510). Vertical jump,
mechanical power, flight time, and maximal leg strength
were measured before and after 12 weeks of training. Sub-
jects in each training group trained 3 days per week, where-
as control subjects did not participate in any training activ-
ity. Data were analyzed by a 2-way (4 32) analysis of var-
iance (repeated-measures design). Results showed that all
training treatments elicited significant (p,0.05) improve-
ment in all tested variables. However, the combination train-
ing group produced improvements in vertical jump perfor-
mance and leg strength that were significantly greater than
improvements in the other 2 training groups (plyometric
training and weight training). This study provides support
for the use of a combination of traditional and Olympic-style
weightlifting exercises and plyometric drills to improve ver-
tical jumping ability and explosive performance in general.
Key Words: stretch-shorten cycle, power training, flight
time, leg strength
Reference Data: Fatouros, I.G., A.Z. Jamurtas, D. Leon-
tsini, K. Taxildaris, N. Aggelousis, N. Kostopoulos, and
P. Buckenmeyer. Evaluation of plyometric exercise
training, weight training, and their combination on
vertical jumping performance and leg strength. J.
Strength Cond. Res. 14(4):470–476. 2000.
Introduction
V
ertical jumping constitutes an integral component
of explosive performance in numerous athletic ac-
tivities. As such, jumping ability is crucial in the exe-
cution of many athletic skills, such as rebounding in
basketball, spiking in volleyball, and high jumping.
Therefore, it is important to determine the parameters
involved in vertical jumping and develop them
through proper training regimens.
Several factors have been established as major de-
terminants of vertical jumping performance; these in-
clude force developed by the hip, knee, and ankle
joints, the rate of force development (muscle power)
produced by these muscles (32), and the neural coor-
dination of the movement (32). The extent to which
jumping performance can be improved by training
seems to depend on subjects’ strength status before the
initiation of the training program. Specifically, it has
been shown that subjects of a low-strength profile ex-
hibited substantial increments in their jumping ability
following training (2, 8, 21), whereas previously
strength-trained subjects experienced limited increase
in their jumping score after additional training (27).
Despite the fact that vertical jumping performance
seems to depend on leg strength, a low correlation be-
tween leg strength and vertical jumping performance
has been obtained (r50.35 and r50.40) on 2 occa-
sions (24, 34), but this may be due to the way leg
strength was assessed (dynamic vs. static measure-
ment) and the speed of movement adapted during the
measurement (4).
Jumping is a complex multijoint action that de-
mands not only force production but also a high pow-
er output. Numerous investigators have underlined the
significance of maximal rate of force development in
the improvement of explosive jumping performance
(9, 27, 39). Plyometric training has been advocated for
sports that require explosiveness and increased verti-
cal jumping ability by the athletes.
Effects of Plyometric and Weight Training on Vertical Jump and Leg Strength
471
Table 1. Descriptive data of subjects’ characteristics.
Group* nHeight (cm) Weight (kg) Age (y)
Control 10 181 61.5 80.8 63.1 20.5 61.8
PT 11 178 62.1 83.4 64.8 21.1 62.5
WT 10 180 61.9 85.0 62.7 20.9 62.4
PWT 10 178 63.0 79.9 62.2 20.1 61.4
*PT 5plyometric training; WT 5weight training; and
PWT 5plyometric plus weight training.
Plyometric or stretch-shortening cycle exercises are
those that are characterized by rapid deceleration of
the body followed almost immediately by rapid accel-
eration of the body in the opposite direction (35). Ply-
ometric exercises evoke the elastic properties of the
muscle fibers and connective tissue in a way that al-
lows muscle to store energy during the deceleration
phase and release that energy during the acceleration
period (5, 6, 14, 20, 26, 30, 43). The end result is that
muscles are trained under tensions greater than those
achieved by conventional slow-speed resistance train-
ing (28). Therefore, plyometric training has been rec-
ommended for sports that rely on generation of high
power output. Researchers and practitioners assumed
that these characteristics of plyometric exercises would
facilitate significant gains in muscle strength and pow-
er and therefore optimize jumping performance. De-
spite the support for plyometrics in improving power
(6, 11, 12, 17, 18, 23), their effectiveness in improving
jumping performance is less clear. Specifically, most
studies revealed that plyometric training resulted in
increased vertical jumping performance (2, 3, 11, 14,
18), although some studies indicated otherwise (2, 10,
37, 45), and one study showed improvement of vertical
jumping performance only after 18 months of plyome-
tric training (13).
Weight training has been able to improve vertical
jumping performance in most cases by 2–8 cm (or by
5–15%) (2, 3, 10, 11, 45), with lighter more explosive
lifts being more effective than the heavier and slower
lifts (27, 45). The comparison of plyometric exercises
and weight-training protocols has produced contro-
versial results. Plyometric protocols have been shown
to be more effective (44), equally effective (2, 3), or less
effective (25, 44) than weight training in improving
vertical jumping ability. Furthermore, 2 other studies
showed that plyometric training was no more effective
than isokinetic training (10) or flexibility training alone
(40).
The combination of plyometric exercises and
weight training increased (2, 8, 10) or maintained un-
affected vertical jumping performance (25). Adams et
al. (2) suggested that this combination may provide a
more powerful training stimulus to vertical jumping
performance than either weight training or plyometric
training alone. However, Clutch et al. (21) did not
reach similar conclusions.
It seems that researchers have not come to an
agreement about the relative effectiveness of plyome-
tric training compared with weight training or the
combination of both in the development of vertical
jumping ability. It seems likely that different durations
of training periods, different training status of the sub-
jects, or different training designs (i.e., training loads
or volumes or exercises) might have caused the dis-
crepancy in the results of previous studies. Therefore,
the purpose of the present investigation was to deter-
mine how selected variables of vertical jumping per-
formance, namely, leg power, jumping height, flight
time, ground time, and leg strength, are affected by a
typical 12-week plyometric training program, a typical
12-week weight-training program, and 12-week train-
ing program that combines plyometric exercises and
weight training.
Methods
Subjects
Forty-one healthy men (20.7 61.96 years of age) vol-
unteered to participate in this study (subjects’ char-
acteristics are given in Table 1). Although subjects
could be classified as untrained (they did not partici-
pate in organized weight or other types of training),
they were able to lift at least 1.5 times their body
weight in the squat exercise. (Those who were not able
to lift that amount of weight were discharged from the
study.) Subjects received all necessary information
about the study’s procedures in oral and written form.
Each subject completed a medical history form (special
care was given to hypertension and orthopedic status
screening), a training background questionnaire, and
a written informed consent form. The study was ap-
proved by the university’s institutional review board
and conformed to requirements set by the American
College of Sports Medicine.
Data Acquisition
Each subject underwent measurements of vertical
jumping performance, leg power, flight time, and max-
imal leg strength. Pretesting was conducted in 4 ses-
sions 1 week before initiation of the training period.
The first session included an introduction of the test-
ing protocols to the subjects. The second session in-
cluded measurement of vertical jumping performance
and flight time. In the third session, leg strength was
determined. During the fourth session, leg power was
measured. There was a 24-hour pause between testing
sessions. Identical measurements were performed in
the same order 4 days following the completion of the
training period.
Vertical Jump Height
Vertical jump height was measured by the stand and
reach test (41). A vertical jump board marked in cen-
472 Fatouros, Jamurtas, Leontsini, Taxildaris, Aggelousis, Kostopoulos, and Buckenmeyer
timeters was used. A vertical jump test was completed
from a 2-footed standing position without a step into
the jump. Subjects were allowed to use their hands as
they desired. Three test jumps were completed, and
the highest of these was recorded. This test was se-
lected because it has high validity (0.80) and reliability
(0.93) coefficients (38) and because it allows arm move-
ment and a squat motion before the jump, such as
those performed in sports.
Measurement of Jumping Mechanical Power
Jumping mechanical power was obtained by use of the
Vertical Jump Test by Bosco et al. (15). This test was
preferred because it takes advantage of the potential
for using elastic energy storage in addition to chemi-
cal-mechanical energy conversion. The test has been
shown to have high validity (compared with the Win-
gate test, 0.87) and reliability (test-retest, 0.95) coeffi-
cients (15). The test calculates mechanical power both
for 15- and 60-second jumping intervals. The 15-sec-
ond jumping interval was selected, since it reflects real
jumping conditions in sports performance and exhib-
its a high validity coefficient when compared with the
Wingate power test (0.87) (15). A Dekan Automatic
Performance Analyzer was used. Two switch mats for
the timer were placed side by side and connected by
a Y adapter to the timer (‘‘start on break contact’’ in-
put). The timer was triggered by the feet of the subject
at the moment of release from the platform and
stopped at the moment of touch down. Thus, the flight
time of the subject during the jump was recorded. This
method of flight time calculation assumes that the po-
sitions of the jumper on the platform were the same
in takeoff and landing. The error of measurement,
when compared with film analysis, has been reported
to be approximately 62% (30). If several jumps are
performed, the timer is summing the respective flight
times of the single jumps. To standardize the knee an-
gular displacement during the contact phase, the sub-
ject was required to bend the knees to about 908. Fur-
thermore, to avoid unmeasurable work output, hori-
zontal and lateral displacements should be minimized,
and the hands were required to be kept on the hips
throughout the jump (15). Jumping frequency was vi-
sually counted and recorded manually by 2 testers for
15 seconds. The average power output during the trial
was computed as follows:
Power (W)
9,8 3total flight time (sec) 360
5(1)
43number of jumps 3(60 2total flight time)
Measurement of Flight Time
The Dekan Automatic Performance Analyzer, which
was selected to measure jumping mechanical power,
was used for the measurement of flight time and
ground time. Subjects performed 3 single jumps, and
the time they remained in the air was recorded (the
best flight time of the 3 was recorded). Ground time
was defined as the amount of time subjects were in
contact with the ground between successive jumps.
Ground time was selected for measurement as an in-
dication of the time delay between the eccentric and
concentric phase of the jump (42). Subjects had to ex-
ecute maximal jumps for 15 seconds. To standardize
the knee angular displacement during the contact
phase, subjects were required to bend the knees to
about 908. The following formula (15) was used to cal-
culate ground time:
Tc (s)
5Total Time (2)
2Total Flight Time (for Number of Jumps)/n
Measurement of Leg Strength
Leg strength was assessed by 2 weightlifting tests: the
1RM (1 repetition maximum) squat and 1RM leg press
tests. Bilateral leg press tests were completed using
standard leg press equipment (Universal, Irvine, CA),
with the subjects assuming a sitting position (about
1208flexion at the hips, 1008flexion at the knees, and
108dorsiflexion) and the weights sliding vertically.
During the lifts, the subjects extended their hips and
knees, with ankle plantar flexion to about 108. The sub-
jects’ 1RM weight was determined within 2–5 lifts, us-
ing weight increments selected by the subjects.
In the squat 1RM test, subjects executed the tradi-
tional back squat exercise following the NSCA guide-
lines for the execution of this particular test. However,
a manual goniometer was used at the knee to stan-
dardize range of motion. Subjects started the squat ex-
ercise at 308of knee flexion, descended to 908, and then
forcefully returned to the starting position by extend-
ing both knees and hips and plantar flexing at the an-
kles. Testers alerted the subjects when the starting and
finishing positions were attained.
Training Protocols
After the initial measurements, subjects were random-
ly assigned to 1 of 4 groups: control (n510), ply-
ometric training (n511), conventional weight training
(n510), and combination of plyometric plus weight
training (n510). The control group did not train. All
other 3 training groups trained for 12 weeks 3 days
per week. Before the initiation of the training periods,
subjects of all groups were instructed about the proper
execution of all the exercises to be used during the
training period for all training regimens. The training
protocols included only leg exercises. None of the sub-
jects had used plyometric exercises before. The train-
ing programs were designed to overload the leg mus-
cles involved in vertical jumping motion. All training
sessions were supervised.
Weight Training Protocol. Traditional leg exercises
Effects of Plyometric and Weight Training on Vertical Jump and Leg Strength
473
were used. Barbell squats, leg presses, leg curls, and
standing calf raises were used as core exercises in the
first 8 weeks, whereas jump squats (with a barbell),
cleans, snatches, and push presses were used as core
exercises in the last 4 weeks, supplemented by front
and side lunges, step ups, sitting calf raises, and dead
lifts in all 12 weeks of training. During the first 2
weeks, training intensities (average weight lifted or
percentage of 1RM lifted, 2 sets at 1 312 and 1 310)
and volumes (repetitions 3weight lifted) were kept
relatively low (weight lifted corresponded to approx-
imately 70% of 1RM) to accommodate subjects with
the training protocol. In the remaining training period,
intensity for the core exercises was maintained be-
tween 80 and 95% of each subject’s 1RM, whereas sup-
plementing exercises were performed constantly at 70–
80%. The first training day of the week included high-
intensity (2 36,134,132), the second day inter-
mediate-intensity (2 310, 2 38), and the third day
low-intensity (4 312) exercises. Supplementing exer-
cises were performed at 1 312, 1 310, and 1 38.
Increases in training weight were adjusted carefully to
ensure that the subjects were able to complete the re-
quired sets and repetitions. (If a subject was perceived
to be using too little weight, adjustments were made.)
Plyometric Training Protocol. Plyometric exercises in-
cluded squat jumps, jumps over cones and bench, re-
peat triple jumps, single- or double-leg hops, alternate
leg bounds, depth jumps, and box jumps. Training in-
tensity and volume was kept low (up to 80 foot con-
tacts with low-intensity drills, while technique was
given special attention) during the first 2 weeks to
avoid injuries and have subjects adjusted to this new
(to them) type of training. During the remainder of
the training period (10 weeks), the first training day
of the week included high intensity of about 220 foot
contacts, the second included moderate-to-high inten-
sity of about 150–170 foot contacts, and the third day
included low-to-moderate intensity of about 120 foot
contacts. However, box jumps and depth jumps were
introduced in the sixth week of training, and the
height of boxes varied, depending on the training day
and the week within the program (started with 30 cm
and reached a high of 80 cm).
Plyometric Plus Weight Training Program. The com-
bined program consisted of a weight-training regimen
in conjunction with a plyometric routine that included
exercises used in the 2 protocols separately as de-
scribed above. The 2 protocols were performed on the
same day, with weight training taking place 180 min-
utes after the plyometric exercise program. The train-
ing intensities followed the same progression as the
ones used in the plyometric and weight-training
groups.
Statistical Analyses
A factorial, 2-way (4 32, 4 treatments by 2 times of
measurement) analysis of variance (repeated-measures
design) procedure was used to test for statistically sig-
nificant differences on all criterion variables across
time. Following a statistically significant Fratio, a
Newman-Keuls post hoc technique was used to clarify
the interaction. The 0.05 level was adopted as the prob-
ability level of significance throughout the analysis.
Data are presented as mean 6SE.
Results
Means and SEs for vertical jump height, jumping me-
chanical power, flight time, and leg strength (in leg
press and squat tests) are listed in Table 2. The com-
bination training group exhibited significantly (p,
0.05) better performance than the plyometric training
and the weight-training groups in vertical jump
height, jumping mechanical power, and flight time.
However, in leg press– and squat-measured leg
strength, the combination group presented significant-
ly (p,0.05) higher improvement compared with the
plyometric training group but not compared with the
weight-training group.
Discussion
The purpose of this study was to determine if ply-
ometric training alone or in combination with weight
training can enhance selected variables of vertical
jumping performance. The results indicate that long-
term plyometric training is capable of improving ver-
tical jumping ability, but its combination with weight
training is even more beneficial.
The effectiveness of plyometric training in improv-
ing explosive performance has been supported by
most training studies in the field during the last 2 de-
cades (11, 14, 25, 30). Despite its wide use in athletics
and the specific guidelines given regarding its use,
more studies are needed to evaluate its effectiveness,
especially compared with other conventional training
methods such as weight training or its combination
with them. Combination of different training methods
will promote all qualities of muscle power and
strength.
Several previous investigations have failed to find
that plyometric training is significantly more effective
than other training methods in improving vertical
jumping ability (21, 25, 28, 33, 35). Furthermore, pre-
vious research that used a combination of plyometric
and weight training found either increased (2, 8, 10)
or unaffected vertical jumping performance (25). Oth-
er investigators (21, 33) found that the combination of
plyometric and weight training is equally effective to
plyometric or weight training. Results of the present
study indicate otherwise. This combination training
provided the most powerful stimulus in improving
various parameters of vertical jumping ability.
In contrast to previous studies, results of the pre-
sent study indicate that all treatments produced pro-
474 Fatouros, Jamurtas, Leontsini, Taxildaris, Aggelousis, Kostopoulos, and Buckenmeyer
Table 2. Means 6SEs between pretraining and posttraining for all dependent variables for the 3 groups.*
Group
VJH
(cm)
Power
(W/kg)
FT
(ms)
GT
(ms)
Leg press
(kg)
Squat
(kg)
Control (n510)
Pre 54.5 61.5 44.8 63.8 528 610.01 333 62.8 191.5 65.8 128.5 64.1
Post 54.9 61.9 45.1 13.5 533 610.09 333 63.6 194.2 66.4 130.2 63.8
PT (n511)
Pre 52.9 62.4 46,5 66.9 515 610.45 344 64.1 202.9 68.3 132.4 66.4
Post 58.9 62.3†‡§ 58.4 67.4†‡§ 578 610.31†‡§ 277 63.2†‡§ 221.3 67.3†‡§¶ 148.8 66.6†‡§¶
WT (n510)
Pre 58.1 61.4 46.5 64.0 522 612.39 343 64.5 189.8 69.3 133.0 64.4
Post 63.5 61.8†‡\58.0 64.0†‡\566 612.19†‡\290 64.8†‡\217.5 67.4†‡¶ 161.9 63.3†‡¶
PWT (n510)
Pre 58.8 63.0 43.0 64.6 508 620.53 341 62.9 133.0 68.9 125.0 64.5
Post 67.4 62.8†‡§\59.9 15.0†‡§\597 621.44†‡§\258 62.7†‡§\216.5 67.6†‡§ 161.1 63.4†‡§
* VJH 5vertical jump height; FT 5flight time; GT 5ground time; PT 5plyometric training; WT 5weight training; PWT
5plyometric plus weight training.
† Significant difference between pretraining and posttraining (p,0.05).
‡ Significant difference with the control group (p,0.05).
§ Significant difference between the PT and PWT groups (p,0.05).
\Significant difference between the WT and PWT groups (p,0.05).
¶ Significant difference between the PT and WT groups (p,0.05).
found improvement in vertical jumping performance
and leg power. However, the combination training
treatment evoked the most significant changes in these
variables. The discrepancy between these results and
results of previous investigations might be attributed
to several reasons. First, the training experience level
of the study subjects might offer one explanation. Sub-
jects in the present study were novices in plyometric
training in contrast to subjects in previous investiga-
tions. However, they were strength trained enough to
be able to sustain plyometric training loads. One needs
to be weight trained to enjoy positive adaptations to
plyometric training. The second explanation is the na-
ture of the training protocols used in the present study
and previous investigations. The present study used a
large variety of plyometric and weight-training exer-
cises compared with previous studies. During the first
phase of training, the weight-training protocols used
general strength training exercises (i.e., squats) aimed
at increasing maximal strength of the lower limb mus-
cles. During the last stage of training, special strength
exercises (i.e., snatches, cleans, jump squats) were used
to convert maximal strength to power as it relates to
jumping (7). This special type of strength training ex-
ercises are characterized by a more forceful and rapid
execution, generation of a higher power output, and
loss of foot contact with the ground (7). In plyometric
training protocols, several exercises were used, rang-
ing from bounds and hops to drop jumps. Another
difference between the present study and previous
ones is the model used to provide the training stim-
ulus to subjects. Training intensity, volume, and exer-
cise selection followed the principle of progressive
overload, starting with lower intensities, single-joint
exercises, and less complex exercise techniques and
progressing to higher intensities, multijoint exercises,
and more complex techniques. Intensity varied within
a single week. Training programs focused on devel-
oping basic strength and exercise technique initially,
maximal strength later, and finally transition of max-
imal strength to power.
Plyometric training resulted in a slightly better im-
provement than weight training in vertical jump per-
formance, but it was not statistically significant. These
results are in agreement with previous findings, in-
dicating that these 2 methods are equally effective in
improving jumping performance (1, 3). Lately, weight-
training protocols have been modified by incorporat-
ing more dynamic and explosive movements aimed
toward power development. Such weight-training pro-
tocols have been found to be very effective in improv-
ing mechanical power in movements requiring explo-
siveness (31, 45).
Even though plyometric and weight training each
increased flight time and decreased ground time sig-
nificantly, it is their combination that caused the great-
est gains in these 2 parameters. It has been suggested
that the increased efficiency of plyometric movements
and generally in stretch-shortening cycle exercises is
due to the fact that previous stretching decreases the
time in which positive work is done during the sub-
sequent shortening (16, 17, 20). Part of the positive
Effects of Plyometric and Weight Training on Vertical Jump and Leg Strength
475
work measured does not derive from chemical energy
transformation but from recoil of tense elastic elements
(20). If the time delay between the stretch and the con-
centric contraction is too long, the energy stored dis-
sipates as heat (18). In the present study, results
showed that combination training decreased ground
time or the amortization phase between jumps (there-
by decreasing the time that the feet were in contact
with the ground between jumps). This adaptation
might have occurred because of a better utilization of
the stored elastic energy, resulting in a higher jump
and increased flight time (and thus reduced ground
time). Mechanical power results followed the same
trend between groups. Interestingly, maximal strength
as measured in leg press was improved more by
weight training than by plyometric training, whereas
maximal strength as measured by the squat exercise
was equally increased by the 2 treatments. This finding
probably is related to the nature of the plyometric and
weight-training exercises used.
Another interesting note is that, despite the fact
that subjects in the combination group performed ply-
ometric and weight training on the same day, their
performance was not impaired. NSCA and others (22,
36) do not recommend performing heavy strength and
plyometric training on the same day, with the excep-
tion of track and field athletes, who might benefit from
‘‘complex training.’’ In the present study, there was
enough rest between sessions to allow recovery of the
neuromuscular and metabolic systems of the subjects.
Plyometric training was performed first to ensure that
subjects would perform the plyometric drills with the
proper technique and full explosiveness.
However, some extraneous variables might have
confound the results of this study. It is very difficult
to control the total work performed in each training
session so that subjects in all groups handle the same
amount of total work. Total workload was not equated
between groups. Authors followed a traditional train-
ing scheme in each treatment based on the periodiza-
tion model. There is a possibility that subjects in the
combination training group were exposed to a higher
training stimulus than subjects in the other groups. It
would be very interesting if future studies made an
attempt to equate workloads between groups when
comparing different training methods.
Therefore, the results of this study indicate that
both plyometric and weight training are able to im-
prove selected variables of vertical jumping perfor-
mance. However, it is their combination that produced
the greatest improvement on these selected variables
of vertical jumping performance.
Practical Applications
The results of this study provide insight into several
aspects of vertical jump training and into training for
improvement of athletes’ explosiveness. First, very im-
portant parameters of vertical jumping performance
can be improved significantly by either plyometric or
weight training separately. However, strength and con-
ditioning professionals must notice that in this study
the combination of plyometric and weight training was
significantly more beneficial in increasing vertical
jump height and other related variables. Therefore,
strength professionals must be able to incorporate both
elements in their training regimens. Second, weight
training must incorporate special exercises, that is, ex-
ercises (such as power jumps, snatches, pulls, power
cleans, and push presses) that focus on power devel-
opment once strength levels have been improved.
Third, intensity and training volume followed the pro-
gressive overload principle in the present study. Inten-
sity and volume of training built up, gradually allow-
ing subjects to adjust effectively, especially subjects
who followed the plyometric training protocols. Vari-
ation of intensity within each week of training seems
to have helped subjects who participated in all train-
ing groups. Fourth, despite the fact that execution of
plyometric training and weight training is not gener-
ally recommended on the same day, the present study
indicates that this might not be true if adequate recov-
ery is allowed in between. Fifth, it seems that 12 weeks
is adequate for improvement of vertical jumping if the
training protocols maintain the appropriate intensity
and volume. Sixth, in this study, 3 days of training per
week was proven an effective training frequency for
vertical jump training. However, this cannot be accom-
plished during the in-season period. Such training
protocols should be incorporated in the preseason or
postseason training periods. Seventh, the results of
this study concern individuals relatively inexperienced
in jump training. It is possible that advanced athletes
in power sports would not exhibit the same magnitude
of improvement with the training protocols used here-
in. It is possible that more advanced athletes need a
different manipulation of training intensity and vol-
ume and selection of exercises.
References
1. A
DAMS
, T. An investigation of selected plyometric training ex-
ercises on muscular leg strength and power. Track Field Q. Rev.
84:36–40. 1984.
2. A
DAMS
, K., J.P. O’S
HEA
, K.L. O’S
HEA
,
AND
M. C
LIMSTEIN
.The
effect of six weeks of squat, plyometrics and squat-plyometric
training on power production. J. Appl. Sport Sci. Res. 6:36–41.
1992.
3. A
NDERST
, W.J., F. E
KSTEN
,
AND
D.M. K
OCEJA
. Effects of ply-
ometric and explosive resistance training on lower body power.
Med. Sci. Sports Exerc. 26:S31. 1994.
4. A
SHLEY
, C.D.,
AND
L.W. W
EISS
. Vertical jump performance and
selected physiological characteristics of women. J. Strength
Cond. Res. 8:5–11. 1994.
5. A
SMUSSEN
, E. Apparent efficiency and storage of elastic energy
in skeletal muscles in man. Acta Phys. Scand. 91:385–392. 1974.
6. A
SMUSSEN
,E.,
AND
F. B
ONDE
-P
ETERSEN
. Apparent efficiency
476 Fatouros, Jamurtas, Leontsini, Taxildaris, Aggelousis, Kostopoulos, and Buckenmeyer
and storage of elastic energy in human muscles during exer-
cise. Acta Physiol. Scand. 92:537–545. 1974.
7. B
AKER
, D. Improving vertical jump performance through gen-
eral, special, and specific strength training: A brief review. J.
Strength Cond. Res. 10:131–136. 1996.
8. B
AUER
, T., R.E. T
HAYER
,
AND
G. B
ARAS
. Comparison of training
modalities for power development in the lower extremity. J.
Appl. Sport Sci. Res. 4:115–121. 1990.
9. B
EHM
,D.G.,
AND
D.G. S
ALE
. Velocity specificity of resistance
training. Sports Med. 15:374–388. 1993.
10. B
LAKEY
, J.B.,
AND
D. S
OUTHARD
. The combined effects of
weight training and plyometrics on dynamic leg strength and
leg power. J. Appl. Sports Sci. Res. 1:14–16. 1987.
11. B
LATTNER
,S.,
AND
L. N
OBLE
. Relative effects of isokinetic and
plyometric training on vertical jump performances. Res. Q. 50:
533–538. 1979.
12. B
OBBERT
, M.F. Drop jumping as a training method for jumping
ability. Sports Med. 9:7–22. 1990.
13. B
OSCO
,C.,P.V.K
OMI
,
AND
A. I
TO
. Prestretch potentiation of
human skeletal muscle during ballistic movement. Acta Physiol.
Scand. 111:135–140. 1981.
14. B
OSCO
,C.,P.V.K
OMI
,M.P
ULLI
,C.P
ITTERA
,
AND
H. M
ONTO
-
NEV
. Considerations of the training of elastic potential of hu-
man skeletal muscle. Volleyball Tech. J. 1:75–80. 1982.
15. B
OSCO
,C.,P.V.K
OMI
,J.T
HIHANY
,G.F
EKETE
,
AND
P. A
POR
.
Mechanical power test and fibre composition of human leg ex-
tensor muscles. Eur. J. Appl. Physiol. 51:129–135. 1983.
16. B
OSCO
, C., I. T
ARKKA
,
AND
P. V. K
OMI
. Effect of elastic energy
and myoelectric potentiation of triceps surea during stretch-
shortening cycle exercise. Int. J. Sports Med. 2:137–140. 1982.
17. B
OSCO
,C.,J.T.V
ITASALO
,P.V.K
OMI
,
AND
P. L
UHTANEN
. Com-
bined effect of elastic energy and myoelectrical potentiation
during stretch shortening cycle exercise. Acta Physiol. Scand.
114:557–565. 1982.
18. B
ROWN
, M.E., J.L. M
AYHEW
,
AND
L.W. B
OLEACH
. Effect of ply-
ometric training on vertical jump performance in high school
basketball players. J. Sports Med. Phys. Fitness Q. Rev. 26:1–4.
1986.
19. C
AVAGNA
, G. Positive work force by a previously stretched
muscle. J. Appl. Physiol. 24:21–32. 1968.
20. C
AVAGNA
, G. Storage and utilization of elastic energy in skel-
etal muscle. Exerc. Sports Sci. Rev. 5:89–129. 1977.
21. C
LUTCH
, D., M. W
ILTON
,C.M
C
G
OWN
,
AND
G.R. B
RYCE
.The
effect of depth jumps and weight training on leg strength and
vertical jump. Res. Q. 54:5–10. 1983.
22. C
HU
, D.A. Explosive Power and Strength. Champaign, IL: Human
Kinetics, 1996.
23. C
HU
, D.A. Jumping into Plyometrics. Champaign, IL: Human Ki-
netics, 1996.
24. C
ONSIDINE
,W.,
AND
W. S
ULLIVAN
. Relationship of selected tests
of leg strength and leg power on college men. Res. Q. 44:404–
415. 1973.
25. F
ORD
, J.R., J.R. P
UCKETT
,J.P.D
RUMMOND
,K.S
AWYER
,K.
K
NATT
,
AND
C. F
USSEL
. Effects of three combinations of ply-
ometric and weight training programs on selected physical fit-
ness test items. Percept. Mot. Skills 56:59–61. 1983.
26. F
UKASHIRO
, S., H. O
HMICHI
,H.K
ANEHISA
,
AND
M. M
IYASHITA
.
Utilization of stored elastic energy in leg extensors. In: Biome-
chanics VIII-A. H. Matsuie and K. Koboyaski, eds. Champaign,
IL: Human Kinetics, 1983. pp. 253–263.
27. H
A
¨KKINEN
,K.,
AND
P. V. K
OMI
. Changes in electrical and me-
chanical behavior of leg extensor muscles during heavy resis-
tance strength training. Scand. J. Sports Sci. 7:55–64. 1985.
28. H
OLCOMB
, W.R., J.E. L
ANDER
, R.M. R
YTTLAND
,
AND
G.D. W
IL
-
SON
. The effectiveness of a modified plyometric program on
power and the vertical jump. J. Strength Cond. Res. 10:89–92.
1996.
29. J
ASTER
,S.,
AND
C. F
RAZIER
. Developing volleyball power. Ath-
letic J. 77:33–38. 1977.
30. K
ANEKO
,M.,T.F
UCHIMOTO
,H.T
OJI
,
AND
K. S
UEI
. Training
effect of different loads on the force velocity relationship and
mechanical power output in human muscle. Scand. J. Sports Sci.
5:50–55. 1983.
31. K
OMI
,P.,
AND
C. B
OSCO
. Utilization of stored elastic energy in
leg extensor muscles by men and women. Med. Sci. Sports Exerc.
10:261–265. 1978.
32. K
RAEMER
,W.J.,
AND
R.U. N
EWTON
. Training for improved ver-
tical jump. Gatorade Sports Sci. Inst. Rep. (Sports Sci. Exchange)
7(6) 1994.
33. L
YTTLE
, A.D., G.J. W
ILSON
,
AND
K.J. O
STROWSKI
. Enhancing
performance: maximal power versus combined weights and
plyometrics training. J. Strength Cond. Res. 10:173–179. 1996.
34. M
ISNER
, J.E., R.A. B
OILEAU
, S.A. P
LOWMAN
, B.G. E
LMORE
, M.A.
G
ATES
, J.A. G
ILBERT
,
AND
C. H
ORSWILL
. Leg power character-
istics of female firefighter applicants. J. Occup. Med. 30:433–437.
1988.
35. NSCA. Position statement: Explosive/plyometric exercises.
Natl. Strength Cond. Assoc. J. 15(3):16. 1993.
36. NSCA. Essentials of Strength Training and Conditioning. T.R. Bae-
chle, ed. Champaign, IL: Human Kinetics, 1994.
37. P
OOLE
,W.,
AND
M. M
ANEVAL
. The effects of two ten week
depth jumping routines on vertical jump performance as it re-
lates to leg power. J. Swim. Res. 3:11–14. 1987.
38. S
AFRIT
, M.J. Introduction to Measurement in Physical Education and
Exercise Science (2nd ed.). St Louis: C.V. Mosby Company, 1990.
39. S
CHMIDTBLEICHER
, D. Training for power events. In: Strength
and Power in Sport. P.V. Komi, ed. Boston: Blackwell Scientific
Publishers, 1992. pp. 381–395.
40. S
COLES
, G. Depth jumping: Does it really work? Athletic J. 58:
48–55. 1978.
41. S
EMENICK
, D. The vertical jump. Natl. Strength Cond. J. 12:68–
69. 1990.
42. S
TEBEN
,R.,
AND
A. S
TEBEN
. The validity of the stretch-short-
ening cycle in selected jumping events. J. Sports Med. 21:28–37.
1981.
43. S
TONE
,M.,
AND
H. O’B
RYANT
.Weight Training: A Scientific Ap-
proach. Minneapolis: Burgess, 1986.
44. V
ERKHOSHANSKI
,T.,
AND
V. T
ATYAN
. Speed-strength prepara-
tion of future champions. Soviet Sports Rev. 18:166–170. 1983.
45. W
ILSON
, G.J., R.U. N
EWTON
, A.J. M
URPHY
,
AND
B.J. H
ENDRICKS
.
The optimal training load for the development of dynamic ath-
letic performance. Med. Sci. Sports. Exerc. 25:1279–1286. 1993.
