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Abstract

This study examined the effects of a progressive resistance training program in addition to soccer training on the physical capacities of male adolescents. Eighteen soccer players (age: 12-15 years) were separated in a soccer (SOC; n = 9) and a strength-soccer (STR; n = 9) training group and 8 subjects of similar age constituted a control group. All players followed a soccer training program 5 times a week for the development of technical and tactical skills. In addition, the STR group followed a strength training program twice a week for 16 weeks. The program included 10 exercises, and at each exercise, 2-3 sets of 8-15 repetitions with a load 55-80% of 1 repetition maximum (1RM). Maximum strength ([1RM] leg press, bench-press), jumping ability (squat jump [SJ], countermovement jump [CMJ], repeated jumps for 30 seconds) running speed (30 m, 10 x 5-m shuttle run), flexibility (seat and reach), and soccer technique were measured at the beginning, after 8 weeks, and at the end of the training period. After 16 weeks of training, 1RM leg press, 10 x 5-m shuttle run speed, and performance in soccer technique were higher (p < 0.05) for the STR and the SOC groups than for the control group. One repetition maximum bench press and leg press, SJ and CMJ height, and 30-m speed were higher (p < 0.05) for the STR group compared with SOC and control groups. The above data show that soccer training alone improves more than normal growth maximum strength of the lower limps and agility. The addition of resistance training, however, improves more maximal strength of the upper and the lower body, vertical jump height, and 30-m speed. Thus, the combination of soccer and resistance training could be used for an overall development of the physical capacities of young boys.
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Journal of Strength and Conditioning Research, 2006, 20(4), 783–791
2006 National Strength & Conditioning Association
E
FFECTS OF
R
ESISTANCE
T
RAINING ON THE
P
HYSICAL
C
APACITIES OF
A
DOLESCENT
S
OCCER
P
LAYERS
M
ARIOS
C
HRISTOU
,
1,2
I
LIAS
S
MILIOS
,
1
K
ONSTANTINOS
S
OTIROPOULOS
,
1
K
ONSTANTINOS
V
OLAKLIS
,
1
T
HEOFILOS
P
ILIANIDIS
,
1
AND
S
AVVAS
P. T
OKMAKIDIS
1
1
Department of Physical Education & Sport Science, Democritus University of Thrace, Komotini, Greece;
2
Center
for Leisure, Tourism and Sports Research and Development, Intercollege, Nicosia, Cyprus.
A
BSTRACT
.Christou, M., I. Smilios, K. Sotiropoulos, K. Volaklis,
T. Pilianidis, and S.P. Tokmakidis. Effects of resistance training
on the physical capacities of adolescent soccer players. J.
Strength Cond. Res. 20(4):783–791. 2006.—This study examined
the effects of a progressive resistance training program in ad-
dition to soccer training on the physical capacities of male ado-
lescents. Eighteen soccer players (age: 12–15 years) were sepa-
rated in a soccer (SOC; n9) and a strength-soccer (STR; n
9) training group and 8 subjects of similar age constituted a
control group. All players followed a soccer training program 5
times a week for the development of technical and tactical skills.
In addition, the STR group followed a strength training program
twice a week for 16 weeks. The program included 10 exercises,
and at each exercise, 2–3 sets of 8–15 repetitions with a load
55–80% of 1 repetition maximum (1RM). Maximum strength
([1RM] leg press, bench-press), jumping ability (squat jump [SJ],
countermovement jump [CMJ], repeated jumps for 30 seconds)
running speed (30 m, 10 5-m shuttle run), flexibility (seat and
reach), and soccer technique were measured at the beginning,
after 8 weeks, and at the end of the training period. After 16
weeks of training, 1RM leg press, 10 5-m shuttle run speed,
and performance in soccer technique were higher (p0.05) for
the STR and the SOC groups than for the control group. One
repetition maximum bench press and leg press, SJ and CMJ
height, and 30-m speed were higher (p0.05) for the STR group
compared with SOC and control groups. The above data show
that soccer training alone improves more than normal growth
maximum strength of the lower limps and agility. The addition
of resistance training, however, improves more maximal
strength of the upper and the lower body, vertical jump height,
and 30-m speed. Thus, the combination of soccer and resistance
training could be used for an overall development of the physical
capacities of young boys.
K
EY
W
ORDS
. agility, flexibility, growth, running speed, strength,
vertical jump
I
NTRODUCTION
Resistance training is proven to be safe and ef-
fective for adolescents when it is properly de-
signed and supervised. Established scientific
organizations recommend resistance training
for young people to enhance muscular
strength, prevent sport injuries, improve performance in
sports and recreational activities, and affect health and
lifestyle in a positive way (1, 3, 26).
Several studies have shown that resistance training
increases muscular strength more than natural growth in
adolescents (14, 20, 21, 25). However, as far as the effect
of resistance training on motor performance is concerned,
some studies have shown a positive effect on some phys-
ical capacities, whereas other studies have not indicated
a similar effect. For example, after a resistance training
program, vertical jump performance was found to either
increase (21) or not show changes at all (20). When the
effect of resistance training on running speed was ex-
amined, resistance training failed to influence running
performance (20). Similarly, resistance training failed to
affect anaerobic capacity (15, 21). To our knowledge, no
study has examined the effects of resistance training on
flexibility and agility in young boys. Therefore, research
findings concerning the effects of resistance training on
motor performance are either limited or inconclusive, and
further studies of the potential role of resistance training
on physical capacities of adolescents are required to pro-
vide useful information to coaches.
After participating in resistance training programs,
sport performance of youths is expected to improve. An-
ecdotal comments on strength training suggested that
this is enhanced (18). Definitely, sports performance is
the outcome of multiple factors, and it would be difficult
to control and assess the net impact of resistance train-
ing. Nevertheless, Gorostiaga et al. (20) found that hand-
ball throwing velocity in adolescent players increased af-
ter resistance training. Thus, it would be interesting to
examine if strength training would have a positive impact
on specific tasks of soccer involving fast running and ef-
fective handling of the ball at the same time.
On the other hand, it is unknown whether a resistance
training program incorporated with regular soccer train-
ing would enhance the physical capacity of adolescent
players compared with soccer training alone. Soccer is a
sport that requires acceleration, rapid change of direc-
tion, and many powerful movements. Therefore, training
of the sport itself may enhance muscular performance es-
pecially during the developmental period. It would have
been interesting for physical educators and coaches to
recognize if soccer training would have an effect on motor
performance and if resistance training combined with soc-
cer training would have an extra effect on motor perfor-
mance. The purpose of this study was to investigate the
effects of soccer training combined with resistance train-
ing as well as the effects of regular soccer training alone
on physical capacities such as muscular strength, vertical
jump performance, running speed, agility, and flexibility,
and on soccer technique of male adolescent soccer players.
M
ETHODS
Experimental Approach to the Problem
The objectives of this study were to examine (a) the ef-
fects of soccer training on anthropometric characteristics,
784 C
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OTIROPOULOS ET AL
.
T
ABLE
1. Strength training program throughout the 16-week
training period.*
Week Session
Set
repetitions
Intensity
(%1RM)
11215 55–60
2215 55–60
23315 55–60
4215 55–60
35315 55–60
6315 55–60
47215 55–60
8215 55–60
59212 65–70
10 2 12 65–70
611312 65–70
12 2 12 65–70
713312 65–70
14 3 12 65–70
815212 65–70
16 2 12 65–70
917210 70–75
18 2 10 70–75
10 19 3 10 70–75
20 2 10 70–75
11 21 3 10 70–75
22 3 10 70–75
12 23 2 10 70–75
24 2 10 70–75
13 25 2 8 75–80
26 2 8 75–80
14 27 3 8 75–80
28 2 8 75–80
15 29 3 8 75–80
30 3 8 75–80
16 31 2 8 75–80
32 2 8 75–80
*1RM1 repetition maximum.
muscular strength, jumping ability, running speed, agil-
ity, flexibility, and specific technical skills of male ado-
lescent players, and (b) the effects of a combined soccer
and resistance training program for 16 weeks on the
above physical capacities. For these reasons, a team of
male regional soccer players was divided into a strength-
soccer training group (STR) and a soccer training group
(SOC). Soccer training (5 times per week) for the devel-
opment of technical and tactical skills was the same in
both groups. The STR group not only trained in soccer,
but in a strength training program as well, using free
weights and machines twice a week (Table 1). No boy had
regularly participated in any form of resistance training
before this study. To assess the effect of natural growth
on physical capacities, a control group (CON) was used
with boys of a similar age and physical characteristics.
The subjects of this group did not participate in any struc-
tured training program. Anthropometric characteristics,
maximum strength, vertical jump performance, running
speed, agility, flexibility, and soccer-specific technical
skills were measured at the beginning of the training pro-
gram and after 8 and 16 weeks of training.
Subjects
Eighteen soccer players with training experience of 4.3
1.9 years and ranging from 12 to 15 years of age volun-
teered to participate in this study. The boys were equally
divided into 2 groups: STR (13.8 0.4 years; n9) and
SOC (13.5 0.9 years; n9). In addition, 8 boys were
recruited as a CON group (13.3 0.7; n8). The mat-
uration status of the boys was determined according to
the development of pubic hair, based on the Tanner 5-
point scale (23), at the beginning, after 8 weeks, and after
16 weeks of strength training by the same investigator.
There were no significant differences between groups for
age or Tanner ratings. The physical characteristics of the
subjects are presented in Table 2.
All boys underwent medical evaluation before the be-
ginning of the study, and the following exclusion criteria
were used: (a) boys with a chronic pediatric disease; (b)
boys with an orthopedic limitation; and (c) boys who were
not classified as Tanner stage 3–5 at the beginning of the
study. Both the boys and their parents were informed
about the scope and the objectives of the study as well as
the risks associated with strength training. A written con-
sent was obtained from the parents. The experimental
protocol was approved by the Institutional Review Board
Committee.
Training Program
Weight-Training Program. The study was performed at
the beginning of the competitive season. The STR group
followed an introductory weight training program of 4
weeks (2 times per week), focusing on proper lifting tech-
niques with low volume and intensity (2 sets of 15 repi-
titions at 30–50% of 1 repetition maximum [1RM]). Af-
ter this period, players began the strength training pro-
gram, 2 times per week for 16 weeks with a total of 32
training sessions. Weight-training sessions were separat-
ed by at least 48 hours of rest. Each player performed the
exercises in order: leg press, bench press, leg extension,
peck-deck, leg flexion, overhead press, lat pull-downs, calf
raise, sit-ups, and upper-lower back extension. The spe-
cific configuration of the acute program variables during
the course of the 16-week training period is presented in
detail in Table 1. In summary, the intensity was 55% of
the 1RM at the beginning of the program and progres-
sively increased up to 80% of the 1RM. For each exercise,
2–3 sets of 8–15 repetitions with 2–3 minutes of rest be-
tween sets and 3–5 minutes between exercises were per-
formed. When a boy was able to complete the predeter-
mined number of repetitions with proper form and with-
out help, the load was increased by 5%. Subjects per-
formed up to 2–3 sets of 20–30 repetitions of the body
weight exercises.
Strength training was performed before soccer train-
ing, and the duration of each session lasted approximate-
ly 45 minutes. A warm-up period of 10 minutes, including
low to moderate intensity aerobic exercises and stretch-
ing, was carried out before strength training. In addition,
boys performed stretching exercises for about 1 minute
after each set of exercises and for 5 minutes after the end
of each session. A qualified instructor, who monitored
proper exercise techniques and made adjustments in
training load and repetitions, supervised strength train-
ing sessions. No injuries occurred during the training and
testing sessions.
Soccer Training Program. Both training groups fol-
lowed a soccer training program 5 times a week, with
each session lasting 90 minutes. In addition, both
groups participated in a 70-minute official game once a
week (two 35-minute halves). Soccer training focused on
the development of technical and tactical skills first and
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785
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ABLE
2. Anthropometric characteristics for the 3 groups for the 16-week training program (mean SE).*
Group Pretraining 8 weeks Adjusted means 16 weeks Adjusted means
Body mass (kg)
Strength-soccer (n9) 52.0 3.3 54.3 3.4† 56.3 0.4 55.6 3.5† 57.5 0.7
Soccer (n9) 54.1 2 54.3 2.0 54.2 0.4 55.3 2.0†‡ 55.1 0.7
Control (n8) 55.8 4.5 57.4 4.4 55.6 0.4 57.5 4.1 55.8 0.7
Pretraining (covariate) 54.0
Height (cm)
Strength-soccer (n9) 162.0 3.8 164 3.9† 164.7 0.3 165.2 3.9†‡ 165.9 0.4
Soccer (n9) 163.0 2.5 164 2.5† 163.7 0.3 165.3 2.5†‡ 165.0 0.4
Control (n8) 163.2 4.5 164.9 4.2† 164.5 0.4 165.6 4.0† 165.2 0.5
Pretraining (covariate) 162.8
Maturational status (Tanner 5-pt scale)
Strength-soccer (n9) 4.0 0.2 4.2 0.2 4.1 0.1 4.3 0.2 4.3 0.1
Soccer (n9) 3.9 0.3 4.0 0.2 4.0 0.1 4.2 0.1 4.2 0.1
Control (n8) 3.8 0.3 4.0 0.3 4.1 0.1 4.1 0.2 4.2 0.2
Pretraining (covariate) 3.9
Sum of 4 skinfolds (mm)
Strength-soccer (n9) 30.0 1.9 28.3 1.6 38.9 1.4 28.1 1.6 37.6 1.8
Soccer (n9) 40.0 3.5 38.4 3.5 40.4 1.2 37.5 3.3† 39.2 1.6
Control (n8) 58.7 6.6 55.4 5.7 41.2 1.6 47.2 5.5†‡ 34.4 2.1
Pretraining (covariate) 42.3
Body fat (%)
Strength-soccer (n9) 12.2 0.9 11.9 0.7 16.9 0.7 12.0 0.7 16.8 0.8
Soccer (n9) 16.6 1.5 15.8 1.6 16.9 0.6 15.8 1.5 16.9 0.6
Control (n8) 24.8 2.9 23.5 2.6 17.4 0.8 20.3 2.5†‡ 14.6 0.8
Pretraining (covariate) 17.8
Girth, midthigh (cm)
Strength-soccer (n9) 45.4 1.1 46.4 1.4† 48.0 0.3 48.1 1.4†‡ 49.4 0.6
Soccer (n9) 47.7 0.9 48.3 0.8 47.6 0.3 48.9 0.8† 48.3 0.6
Control (n8) 47.9 1.9 49.3 1.8 48.5 0.4 48.3 1.5 47.5 0.6§
Pretraining (covariate) 47.0
Girth, calf (cm)
Strength-soccer (n9) 32.9 0.8 33.1 0.9 34.0 0.2 33.6 0.9† 34.4 0.2
Soccer (n9) 33.9 0.4 34.1 0.6 34.0 0.2 34.4 0.6† 34.2 0.2
Control (n8) 34.5 1.2 34.7 1.2 34.0 0.2 34.2 1.1 33.5 0.2§
Pretraining (covariate) 33.8
Girth, upper arm (cm)
Strength-soccer (n9) 23.8 1.0 23.7 0.9 24.1 0.2 24.0 0.9 24.4 0.2
Soccer (n9) 23.4 0.4 23.0 0.4† 23.7 0.2 23.4 0.4‡ 24.1 0.2
Control (n8) 25.2 1.1 25.4 1.3 24.3 0.2 24.8 1.0 23.8 0.2
Pretraining (covariate) 24.1
Girth, midbiceps (flexed) (cm)
Strength-soccer (n9) 25.7 1261 26.7 0.3 26.4 1 26.9 0.3
Soccer (n9) 26.0 0.5 25.4 0.5 25.7 0.3 25.6 0.5 25.9 0.3
Control (n8) 27.0 1.2 26.9 1.3 26.1 0.3 26.2 1 25.5 0.3
Pretraining (covariate) 26.2
*p0.05.
† From pretraining.
‡ From 8 weeks.
§ Between strength soccer and control.
then on the improvement of physical capacities. Technical
skills, such as dribbling, passing, receiving, shooting, and
heading were performed for 40–50 minutes in at least 3
training sessions a week. In addition, soccer drills and
games were performed in small areas from squads with
a reduced number of players (1 vs. 1, 3 vs. 3, 4 vs. 4) to
work on offensive and defensive strategies and individual
tactics. High-intensity training for the development of
running speed and agility (with and without a ball) was
carried out twice a week, and 1 training session per week
included soccer games or interval training for the devel-
opment of aerobic capacity. A half-field game lasting 20–
30 minutes was played at the end of each training ses-
sion. Stretching exercises for the main muscle groups
were executed in the warm-up and cool-down periods.
Testing Procedures
A standardized 15- to 20-minute warm-up consisting of
submaximal aerobic exercises and stretching exercises
preceded each test.
Anthropometric Measurements. All boys were mea-
sured for height, weight, body fat, and selected girths.
786 C
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Body fat was measured using triceps and calf skinfolds
as described by Slaughter et al. (33). Girth measures of
the upper arm, midbiceps (flexed), midthigh, and calf
(maximum girth of calf muscle) were obtained with an
anthropometric tape measure as described by Callaway
et al. (11). All anthropometric and body composition mea-
sures were taken from the right side by the same inves-
tigator.
Maximum Strength. All boys were evaluated for 1RM
in the bench press and leg press. The 1RM was typically
determined within 6 trials using the protocol of Ramsey
et al. (29). All testing procedures were closely supervised
(an instructor-to-subject ratio was 1:1), and verbal en-
couragement was given to all boys. All measurements
were performed with a constant position of the body, us-
ing the same resistance equipment by the same test ad-
ministrator. The intraclass correlation coefficient (ICC)
and the coefficient of variation (CV) of the SEM for the
measurement of maximum strength were r0.975 and
2.81%, respectively.
Vertical Jump Performance. Vertical jump performance
was measured with 3 types of jumps: a squat jump (SJ;
initiated from a knee flexion of 90), a countermovement
jump (CMJ), and repeated jumps (RJ) for 30 seconds (9,
10). During the performance of the jumps, the hands of
the boys were placed on the waist. The jumps were exe-
cuted on a platform connected to a digital timer (Ergo-
jump, Psion CM; MAGICA, Rome, Italy) that measured
flight time and calculated jump height. For the SJ and
the CMJ, after 2–3 practice trials, 3 trials were carried
out for each type of jump (1–2 minutes of rest were al-
lowed between jumps), and the best trial was used for
further analysis. For the RJ test, the boys were instructed
to jump continuously using maximal effort. For every
jump, the position of takeoff and landing were the same.
To standardize knee angular displacement during the
contact phase, the boys were instructed to bend the knee
to about 90. Pilot testing revealed an ICC and a CV of
the SEM of r0.971 and 2.47% for the SJ, r0.957
and 3.42% for the CMJ, and r0.932 and 3.44% for the
RJ, respectively.
10- and 30-m Sprint Time. Sprint time was measured
using 3 electronic photo cells connected to a Lafayette
63501 timer (Lafayette Instrument Co. Systems, Lafay-
ette, IN). A photocell was placed at the start, at 10 m, and
at 30 m. The first photocell was positioned at a height of
50 cm from the ground and the photocells of 10 and 30 m
were placed at the height of the head of the boys, in an
attempt to standardize the part of the body breaking the
photocell (5). The boys started on a visual signal from a
standing position and ran the 30-m distance as fast as
possible on an indoor running track. After 1 practice trial,
2 sprints were performed, separated by a 5-minute recov-
ery period, and the fastest was used for subsequent anal-
ysis. All performance times were recorded with an accu-
racy of 0.001 seconds, and the time from 0 to 10 m and
total sprint time from 0 to 30 m was recorded. These
sprint distances were selected because they are the most
common during soccer games (6). The ICC and the CV of
the SEM for the 10-m sprint were r0.958 and 1.46%,
and for the 30-m sprint, r0.979 and 0.83%, respective-
ly.
Agility (10
5m).Agility was evaluated using a 10
5-m maximal shuttle run on an indoor running track
following the protocol of Eurofit (16). After 1 practice trial
and at least 5 minutes of rest, a maximum test was per-
formed. Performance time was recorded with an accuracy
of 0.01 seconds. The ICC and the CV of the SEM for the
10 5-m shuttle run test were r0.935 and 1.01%,
respectively.
Flexibility. Flexibility of the lower back and ham-
strings was measured using the sit and reach test as sug-
gested by the American Alliance of Health, Physical Ed-
ucation, Recreation, and Dance (2). Two trials were per-
formed, and the best one was used for further analysis.
The ICC and the CV of the SEM for the sit and reach
test were r0.979 and 2.71%, respectively.
Soccer Technique Test. Technical skills in soccer were
evaluated using a slalom dribble test (35). The boys per-
formed zigzag dribbling with the preferred leg around a
series of 9 cones with a distance of 1.5 m between them
(total distance, 14 m). After 2 practice trials, 2 maximum
efforts of zigzag dribbling were performed separated by a
2-minute rest. The fastest and most successful trial (with-
out losing possession of the ball) was recorded for further
analysis. All performance times were recorded with an
accuracy of 0.001 seconds, using an electronic timer (La-
fayette Instrument Co. Systems). Pilot testing revealed
an ICC and a CV of the SEM of r0.982 and 1.88%,
respectively.
Statistical Analyses
The effects of training on each group were tested using a
repeated-measures analysis of variance and the effect
size ([posttest mean pretest mean]/SD) for the magni-
tude of treatment effects was determined (12, 30). A two-
way analysis of covariance (ANCOVA), using initial val-
ues as covariate and
2
for effect size, was used to deter-
mine the differences between groups at the 8th and 16th
week of training. Statistical power (P) for the ANCOVA
was determined as suggested by Keppel (22). Significant
differences between means were located with the Tukey
honestly significant difference procedure. The statistical
significance level was set at p0.05.
R
ESULTS
Anthropometric Measurements
Significant main effects (p0.05) were observed for
height and weight, but no differences (p0.05) were
found between groups. No significant changes were ob-
served between groups for percentage of body fat and the
sum of 4 skinfolds. Analysis of covariance revealed that
midthigh and calf circumferences were larger (p0.05)
for the STR group compared with the CON after 16 weeks
of training (Table 2).
Maximal Strength
Leg Press (1RM). Training resulted in significant increas-
es (p0.01) in lower body strength for the STR (58.8%)
and SOC groups (33.8%). A significant increase (17.3%; p
0.05), indicative of growth, was also observed for the
control group (Table 3). For all groups, the greatest in-
crease was observed after the first 8 weeks of training
(37.7, 20.7, and 9% respectively). Further analysis (AN-
COVA) revealed significant differences between groups in
maximum strength (p0.01,
2
0.551, P1). Leg
press 1RM for the STR group was greater than that
achieved by the SOC and CON groups after 8 and 16
weeks of training. Maximum strength of the SOC group
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3. Physical performance and soccer technique scores for the three groups for the 16-week training program.*
Group
Pretraining
Means SE
8 weeks
Means SE
Effect
size
Adjusted
means
16 weeks
Means SE
Effect
size
Adjusted
means
Flexibility (cm)
Strength-Soccer (n9) 26.7 1.8 23.7 2.2† 0.5 20.1 1.2 24.6 1.9 0.37 21.2 1.1
Soccer (n9) 22.1 3.8 23.2 3.3 0.11 23.5 1.2 24.7 2.8 0.26 24.9 1.1
Control (n8) 18.3 2.9 18.7 1.2 0.05 22.1 1.2 18.4 2.8 0.01 21.5 1.2
Pretraining (covariate) 22.5
Sprint time 10 m (s)
Strength-soccer (n9) 2.16 0.06 2.18 0.07 0.14 2.14 0.04 2.09 0.04 0.41 2.06 0.03
Soccer (n9) 2.00 0.04 2.04 0.04 0.4 2.13 0.04 1.98 0.04 0.15 2.05 0.03
Control (n8) 2.18 0.05 2.20 0.06 0.12 2.15 0.04 2.11 0.04 0.48 2.07 0.03
Pretraining (covariate) 2.11
Sprint time 30 m (s)
Strength-Soccer (n9) 5.07 0.16 5.16 0.16 0.19 5.13 0.05 4.94 0.12†‡ 0.3 4.91 0.04
Soccer (n9) 4.85 0.09 4.88 0.10 0.1 5.04 0.05 4.85 0.10 0 5.00 0.04
Control (n8) 5.20 0.11 5.26 0.06 0.22 5.12 0.05 5.22 0.10 0.06 5.09 0.04‡
Pretraining (covariate) 5.04
Agility 10 5 m (s)
Strength-soccer (n9) 19.92 0.24 19.25 0.29† 0.83 19.43 0.16 18.84 0.16† 1.74 18.97 0.19
Soccer (n9) 19.78 0.21 19.07 0.22† 1.08 19.34 0.16 18.99 0.24† 1.13 19.19 0.20
Control (n8) 20.86 0.63 20.89 0.41 0.02 20.43 0.18‡§ 21.12 0.40 0.17 20.78 0.22‡§
Pretraining (covariate) 20.18
Mean height of repeated jumps for 30 s (cm)
Strength-soccer (n9) 21.6 1.4 22.4 1.3 0.2 21.4 0.5 24.8 1.4†‡ 0.76 23.7 0.7
Soccer (n9) 22.2 1.3 23.0 1.2 0.21 21.4 0.5 23.7 1.2† 0.41 22.0 0.8
Control (n8) 16.9 1.4 16.9 1.1 0 19.5 0.6 18.3 1.4 0.36 21.0 0.9
Pretraining (covariate) 20.21
Soccer technique test (s)
Strength-soccer (n9) 7.91 0.20 7.51 0.18 0.69 7.95 0.18 7.32 0.10 1.22 7.72 0.19
Soccer (n9) 7.40 0.24 7.21 0.24 0.25 8.08 0.20 7.10 0.26 0.39 7.90 0.22
Control (n8) 10.27 0.55 10.32 0.52 0.03 8.85 0.26§ 10.30 0.51 0.02 8.95 0.28‡§
Pre-training (covariate) 8.52
Squat jump (cm)
Strength-soccer (n9) 24.9 1.4 28.1 1.4† 0.76 27.9 1 32.4 1.6† 1.65 32.1 1
Soccer (n9) 23.8 1.2 25.2 1.2 0.4 25.7 1 25.9 1.1 0.62 26.6
Control (n8) 25 2 26.5 1.8 0.28 26.2 1.1 27 2.1 0.35 26.6
Pretraining (covariate) 24.5
Countermovement jump (cm)
Strength-soccer (n9) 29 1.6 32.9 1.4† 0.86 33.1 0.6 35.7 1.4† 1.49 35.9 0.8
Soccer (n9) 29.7 1.7 30.3 1.5 0.12 30 0.6¶ 31.1 1.3 0.3 30.8 0.8
Control (n8) 29 2 30.6 1.4 0.33 30.7 0.7¶ 31.2 1.5 0.44 31.3 0.9
Pretraining (covariate) 29.2
Leg press 1RM (kg)
Strength-soccer (n9) 102.8 2.5 142.8 8.5† 1.73 148.7 4.7 163.9 7.4† 2.77 170.1 4.4
Soccer (n9) 106.1 7 126.7 6.7† 1 118.9 4.8¶ 139.4 6† 1.7 132.5 4.6¶
Control (n8) 93.8 5.2 102.5 6.7† 0.52 108.3 110 6.8† 0.95 115.2 4.8§
Pretraining (covariate) 100.9
Bench press 1RM (kg)
Strength-soccer (n9) 36 1.6 45.9 2.5† 1.57 50.6 1.1 55 3.1† 2.54 60.6 1.5
Soccer (n9) 48.3 3.2 47.8 2.6 0.01 41.4 1.2¶ 45.8 3.4 0.25 38.2 1.5¶
Control (n8) 39.4 2.7 41 2.4 0.22 42.7 1.1§ 40.5 2.5 0.15 42.5 1.5§
Pretraining (covariate) 41.2
*p0.05.
† From pretraining.
‡ From 8 weeks.
§ Between strength-soccer and control.
Between soccer and control.
Between strength-soccer and soccer.
788 C
HRISTOU
,S
MILIOS
,S
OTIROPOULOS ET AL
.
F
IGURE
1. Differences between the strength-soccer (STR),
soccer (SOC), and control (CON) groups in 1RM leg press and
bench press. *p0.01 between STR and SOC, †p0.01 be-
tween STR and CON, ‡p0.05 between SOC and CON.
F
IGURE
2. Differences between the strength-soccer (STR),
soccer (SOC), and control (CON) groups in countermovement
jump (CMJ) and squat jump (SJ). *p0.05 between STR and
SOC, †p0.05 between STR and CON.
was greater compared with the CON group only at the
end of the 16-week training period (Figure 1).
Bench Press (1RM). After 8 and 16 weeks of training,
bench press 1RM was significantly higher (p0.01) for
the STR group than the SOC and CON groups (p0.01,
2
0.79, P1; Figure 1). In particular, upper body
strength increased only in the STR group (52.3%; p
0.01), whereas no significant differences (p0.05) were
observed for the SOC and CON groups (-5.4 and 3.3%
respectively; Table 3).
Vertical Jump Performance
Squat Jump. After 16 weeks of training, SJ height was
higher (p0.05,
2
0.33, P0.83) for the STR group
compared with the SOC and CON groups (Figure 2). SJ
height was significantly improved by 13.5 and 31% for the
STR after 8 and 16 weeks of training, respectively (p
0.05). The increases observed for the SOC (9.8%) and
CON (9.6%) groups were not significant (p0.05; Table
3).
Countermovement Jump. After 8 and 16 weeks of train-
ing, CMJ height was greater (p0.01,
2
0.49, P1)
for the STR group compared to the SOC and CON groups
(Figure 2). CMJ height improved by 14.4 and 24.6% for
the STR after 8 and 16 weeks of training, respectively (p
0.05). No significant changes were observed for the
SOC (6.3%) and CON (9.5%) groups (Table 3).
Repeated Jumps for 30 Seconds. After 16 weeks of
training, the STR and the SOC groups improved signifi-
cantly in average height during repeated jumps for 30
seconds (15.8 and 7.2%, respectively; p0.05), whereas
the CON group showed a nonsignificant improvement
(9.8%; p0.05). No significant differences were observed
between groups after the end of the training period (p
0.07,
2
0.21, P0.57; Table 3).
Sprint and Agility Times
Running Speed. There were no significant improvements
for 10-m acceleration speed in any group during the
study, although the STR group showed a higher speed
(3.1%) than the SOC (0.7%) and CON (2.7%) groups. No
differences were observed between groups (p0.99,
2
0.01, P0.07). Significant improvements in 30-m
sprint time (p0.05) occurred only with the STR group
R
ESISTANCE
T
RAINING IN
A
DOLESCENTS
789
(2.5%) after 16 weeks of strength training, whereas no
significant differences were found for the SOC (0.04%)
and CON (0.5%) groups. Sprint velocity was higher for
the STR group compared with the SOC and CON groups
at the end of the training period (p0.049,
2
0.24, P
0.65; Table 3).
Agility Time. Improvements were observed in the 10
5-m shuttle run for the STR and SOC groups after 8
(3.4 and 3.5%, respectively; p0.05), and 16 weeks (5.4
and 4%, respectively) of training, whereas no changes
were observed in the CON (1.6%) group. The ANCOVA
revealed significant differences between groups in agility
time (p0.01,
2
0.65, P1) with the STR and the
SOC groups being faster than the CON group (Table 3).
Flexibility
Sit and reach scores decreased significantly by 8.2% in
the STR group (p0.05), whereas they increased, but
not in a significant way, in the SOC and CON groups.
The 3 groups did not differ in flexibility scores throughout
the course of the study (p0.07,
2
0.22, P0.62;
Table 3).
Soccer Technique Test
The STR and SOC groups improved their performance
(6.8 and 4.0%, respectively) in the soccer technique test
after training, but this improvement was not significant
(p0.05). No changes were observed in the CON group
(0.4%; p0.05). The scores in the soccer technique test,
at the end of the training period, were better for both the
STR and SOC groups compared with the CON group,
whereas no differences were observed between them (p
0.05,
2
0.34, P0.83; Table 3).
D
ISCUSSION
The soccer training applied in this study improves agility,
flexibility, and strength of the lower extremities. Strength
training twice a week in addition to soccer training (5
times per week) caused greater increases in upper- and
lower-body strength and improved more vertical jump
performance compared with soccer training alone. Fur-
thermore, strength-soccer training improved agility time
and 30-m running speed compared with subjects who did
not get any structured training. Flexibility decreased
(8%), and 10-m acceleration time was not affected by
strength training.
All 3 groups increased their lower-body strength (leg
press). However, upper-body strength (bench press) im-
proved only in the STR group, whereas the SOC and CON
groups showed minor increases. These results, based on
the principle of specificity, confirm the findings of other
studies in children (29) and adolescents (20, 21). Lower-
body muscles are used more in daily physical activities
and are strengthened faster than the upper-body muscles
that may be used less frequently (29). Therefore, strength
training for the upper-body muscles of adolescents seems
to be necessary for an optimal growth of the whole body
and especially for participants in sports such as soccer,
where strength stimuli for the upper body are rare.
The high acceleration of sprint, the stopping move-
ments after a sprint, and the changes in direction are
actions that occur frequently in soccer. These activities
require the development and application of high forces
from the legs, causing a greater leg strength increase in
our soccer training group than natural growth. The spe-
cific effect that soccer has on leg strength is supported by
the fact that these adaptations are limited to the leg mus-
culature, because maximum strength of the arms, which
are not used in soccer, did not increase.
Specific neural adaptations, such as increased motor
unit recruitment and coordination, and improved coordi-
nation of the involved muscle groups have been reported
after resistance training programs in children and ado-
lescents (28, 29). The STR group improved significantly
in 1RM bench press without any increases in their flexed
midbiceps circumferences, indicating that strength in-
creases were mainly caused by neural adaptations. How-
ever, the possibility of muscular hypertrophy in adoles-
cents caused by strength training should not be over-
looked (8, 21, 25). The strength improvements of the low-
er body muscles (1RM leg press) for the STR group were
accompanied by an increase in midthigh and calf circum-
ferences, with minor changes in midthigh and calf skin-
fold sites. Although circumference increases may follow
natural growth and development (24), our data suggest
the possibility of muscular hypertrophy caused by
strength training. The use of advanced techniques, such
as magnetic resonance imaging, would provide better re-
sults on muscular hypertrophy in adolescents after
strength training.
Vertical jump performance (SJ and CMJ) increased
significantly only in the STR group. Our results confirm
previous studies with prepubescent active men (31, 36)
and pubescent athletes (21). It seems that the increase in
the maximal muscle force, as a result of strength training,
also improves muscular power, despite the absence of spe-
cific exercises for the improvement of jump performance.
To our knowledge this is the first study that shows sig-
nificant improvement in jumping ability as a result of
strength training in adolescent soccer players.
Strength training combined with soccer training or
soccer training alone had no effects on anaerobic capacity,
evaluated with the average height of repeated jumps for
30 seconds. Similarly, other studies using the Wingate
test in preadolescents and adolescent subjects did not find
changes in anaerobic capacity, after strength training (15,
21). In the STR group, SJ and CMJ performance in-
creased to a greater rate than in the SOC and CON
groups. Although no significant differences were observed
between groups for repeated jump performance, the STR
group showed higher performance than the SOC and
CON groups. The results may be caused by the different
neuromuscular and metabolic components of anaerobic
performance. Short-term power output (SJ and CMJ) de-
pends more on the degree of neuromuscular activation
than on energy provision from anaerobic metabolism (27).
Besides the need of high neuromuscular activation, the
30-second all-out test (intermediate anaerobic perfor-
mance) activates anaerobic glycolysis and causes lactate
production because of the length of the protocol. Thus,
when increasing their maximum strength, children and
adolescents can benefit to a greater degree on maximum
anaerobic power.
Running speed has been found to correlate with max-
imum strength and VJ performance (4, 21). However, an
improvement in maximum strength does not assure an
improvement in sprinting velocity as well (13, 37). In a
study concerning a similar age group with ours, Hetzler
et al. (21) did not find an improvement in a 40-yd sprint
in boys who followed strength training. In this study,
790 C
HRISTOU
,S
MILIOS
,S
OTIROPOULOS ET AL
.
however, where the STR group followed strength and
sprint training, a significant improvement in 30-m sprint
time was observed, along with an improvement in maxi-
mum strength and vertical jump performance. Soccer
training did not lead to an improvement in sprint despite
the fact that specific sprint training took place 2 days a
week. It seems that a combination of strength and speed
training may be more beneficial for speed development.
It should be noted, however, that based on the data of our
study, the transfer of strength gain to speed was rather
small (58.8% increase in leg strength vs. 2.5% in 30-m
speed), and a low correlation was observed between the
percent increase in leg strength and 30-m speed (r
0.24).
Agility was affected in a similar way in both the STR
and SOC groups, indicating the specificity of soccer train-
ing. Soccer training drills and games involved continuous
changes of direction. Thus, agility performance improved
with this type of training, without any further contribu-
tion from strength training. Furthermore, it is interesting
to note that the soccer training group improved only dur-
ing the agility test, which involved fast running with
changes in direction, and not in 30-m speed that involved
forward fast running. This probably reflects the specific-
ity of soccer training and the need for targeted speed
training for an overall improvement of soccer perfor-
mance. To our knowledge, the only study that examined
the effects of 12 weeks of strength training in agility in-
volving preadolescent boys was that of Falk and Mor (19)
and it is in agreement with our result. Despite these lim-
ited data, it seems that strength training has a minor
effect on agility performance of young people. There is a
minor transfer of the strength gain to agility, which prob-
ably involves a motor control pattern that is not strongly
influenced by the neural adaptations, which occur with
resistance training.
Flexibility increased in the soccer training group. Al-
though it was not significantly different from the control
group, it seems that the participation in soccer training
does not impair flexibility development when proper care
is taken to include stretching exercises in the training
program. Studies performed in adults reported that if
stretching exercises are part of the strength training pro-
gram, flexibility would not be impaired and it may even
increase (34). In this study, stretching exercises were per-
formed before, during, and after the strength training
sessions. However, flexibility of the hamstrings and the
lower back muscles decreased (8%) in the STR group. Pre-
vious studies involving children and prepubescents re-
ported either increases or no changes in flexibility after
strength training when using programs with low to mod-
erate volume and intensity (17–19, 32, 36). The high
volume and intensity of resistance training or the com-
bination of soccer and resistance training in our study
probably interfered with flexibility. More emphasis was
probably required on specific stretching exercises. Fur-
thermore, our subjects were adolescents and the phase of
their physical development might also interact with flex-
ibility levels. It should be noted that, even in the control
group, a slight decrease in flexibility was observed. Stud-
ies reported that inadequate flexibility might limit joint
mobility and predispose the muscles or the connective tis-
sue to injury and reduced performance (7, 34). However,
no injury was observed during the course of this study in
the STR group and other physical performance compo-
nents improved in this group. In any case, it seems that
additional stretching exercises or sessions for the main-
tenance or improvement of flexibility are necessary to
prevent muscles from becoming tight during strength
training. Further research is needed to determine which
factors might impede flexibility or not when adolescent
soccer players lift weights.
Resistance training had no effects on the soccer tech-
nique test used in this study. The nature of the test (drib-
bling with a ball between cones) is such that resistance
training would have a minor effect in comparison with a
training program focusing more on motor performance
development. This does not mean that resistance training
has no effect on any soccer-related action. If we had used
another soccer-specific test (e.g., speed of the ball after a
shot), we might have seen some sort of effect through the
increased leg force after strength training. For example,
Gorostiaga et al. (20) found that handball throwing ve-
locity in adolescent handball players increased after re-
sistance training. Furthermore, resistance training may
improve performance during a soccer game through a
greater speed and jumping ability, which help the player
to get control of the ball. In any case, it should be noted
that in this study we applied a low-frequency resistance
training program of moderate to submaximal intensity,
using basic core exercises and not sport specific strength
exercises, during the competition period. The aim was not
to maximize soccer performance but to develop the neu-
romuscular system of the athletes and help them to tol-
erate the mechanical stress of the various soccer actions
more and protect them from possible injuries. This might
be even more important than an improved performance
in the sport.
P
RACTICAL
A
PPLICATIONS
Soccer is a popular sport worldwide, and many youths
participate in soccer training programs. Soccer training
in adolescents provides a pleasant pastime and seems to
increase the parameters of physical capacity and soccer-
related skills. Soccer training alone improves maximal
strength of the lower-body muscles and agility, and when
stretching is included in the training program flexibility
also increases. The application of soccer training com-
bined with low frequency of moderate to submaximal in-
tensity resistance training offers an overall development
of physical capacities by improving in a greater degree
soccer-related abilities such as maximal strength of the
upper- and lower-body muscles, VJ performance, and 30-
m speed compared with regular soccer training. More em-
phasis should be given, however, to stretching exercises
when the soccer training program is combined with resis-
tance training. This may prevent any possible inconve-
nience caused after resistance training on flexibility dur-
ing the developmental period.
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Address correspondence to Savvas P. Tokmakidis,
stokmaki@phyed.duth.gr.
... A common trait among 12 of the 13 groups that achieved at least a large ES, was that they all had a background in ball sports (football, rugby or handball). Another possible explanation for the positive trends among athletes who carried out maximal weight training is that they were exposed to high physical demands in their technical and physical training that could have had a marked positive effect on speed [89][90][91][92][93][94]. The fact that ball sports contain a multitude of short-sequence sprints could have resulted in an optimization of intermuscular coordination tailored towards sprinting, compared to performing weight training in isolation [24]. ...
... The groups [74,76], Yáñez-García, et al. [81] consisted of male football players and athletes from basketball between the ages of 16 and 19 years old. A possible explanation for the lack of progression is that they had a high pre-existing maximal power production, which they could have received from previous ball-based training, as football and basketball is a sport that demands the development of and application of a high level of force from the lower body fast across a variety of movements [89,90,92,94] Thus, football and basketball players already would have had a high level of previous training experience with the type of force development that is carried out in explosive weight training with light loads, so they would have required a higher training dose to register any progression [35]. The limitations of the two groups are unlikely related to how good they were at developing maximal power quickly and often, but rather to a lack of strength required to develop high maximal power. ...
... Of the remaining seven groups that recorded progressions in ES, two groups had a moderate ES, while the remining had low ESs, even though four of the experimental groups [84,85,87] contained athletes from ball sports, which provide an additional stimulus for specific adaptation [89][90][91][92][93][94]. The low progression that arises because of hypertrophy training could be a result of training being carried out without intending to achieve maximal speed. ...
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The purpose of this review was to examine how different relative loads in weight training can improve acceleration over 10 m from a standing or flying start. A systematic review of the literature was undertaken using the following databases: PubMed, MedLine, Google Scholar, and SPORTDiscus. Studies were eligible if they met the following criteria: (1) participants were at least 15 years or older and healthy and injury free, (2) the study included at least one exercise for the lower body with a strength training frequency of at least once a week and included a training period of at least four weeks, and (3) interventions with clear pre- and post-test results on 10 m sprint or 10 m flying start are stated. Non-English-language articles were excluded. Percent change and between-group effect size (ES) were calculated to compare the effects of different training interventions. Forty-nine studies met the inclusion criteria. The results were categorized into four groups: (1) explosive weight training with light loads at 30–60% of 1-RM, (2) explosive weight training with moderate loads at 60–85% of 1-RM, (3) maximal weight training at 85–100% of 1-RM, and (4) hypertrophy training at 60–85% of 1-RM. At 10 m, all methods of weight training demonstrated improvements, and maximal weight training demonstrated the highest results with a large ES, while other approaches varied from very small to moderate ES. Weight training showed little progression with a significantly lower effect on flying start across all training methods, except for one group that trained power cleans (hypertrophy) where progress was large. To improve acceleration over the first 10 m, this review demonstrated maximal weight training as the preferred training method. For athletes with a pre-existing high level of strength, it could be more appropriate to use explosive training with light loads or a combination of the two. To a lesser extent, acceleration from a flying start could be improved using both training methods as well.
... Besides DJ training, another method used for vertical jump performance enhancement is weight training. Several studies have shown a concomitant increase of maximal strength and vertical jump performance after lower-body resistance training (7,10,17,18). Interestingly, when weight training is combined with DJ training, there is a superior improvement of vertical jump performance compared with either training modality alone (1,8,11). ...
... Weight training improved vertical jump performance, and the addition of drop jumps lead to even greater improvements. This agrees with several previous reports highlighting the efficacy of weight training (7,10,17,18) or the combination of the 2 training modalities (11,43) which may lead to further performance enhancement. This study, though, reveals that the drop height should be at least equal to the optimum to cause additional benefits compared with weight training alone on slow SSC jump performance. ...
Article
Sotiropoulos, K, Smilios, I, Barzouka, K, Christou, M, Bogdanis, G, Douda, H, and Tokmakidis, SP. Effects of drop jump training from different heights and weight training on vertical jump, maximum strength and change of direction performance in female volleyball players. J Strength Cond Res XX(X): 000-000, 2022-This study compared the effects of drop jump (DJ) training from different drop heights and weight training on vertical jump and maximum strength performance. Fifty-five female volleyball players (age: 23.8 ± 4.3 years) were randomly and equally allocated to a control group (volleyball training, CG); a volleyball and weight training group (WG); and 3 volleyball, weight, and drop jump training groups. One group performed DJ training from the optimal drop height, i.e., the height that elicited the highest ratio of jump height to contact time (OG), a second group from a drop height 25% higher than the optimal (HG), and a third group from a drop height 25% lower than the optimal (LG). Drop jump and weight training were performed 1-2 times per week, for 8 weeks for a total of 13 sessions. After training, vertical jump performance improved by 3.6-17.4% (p < 0.05; effect size [ES]: 1.03-1.23) in the OG and the HG compared with the LG, WG, and CG (p < 0.05; ES: 0.03-0.58). Drop jump height from drop heights 20-70 cm increased by 10.0-20.2% (p < 0.05; ES: 0.59-1.13) for the OG and the HG, while reactive strength index increased (p < 0.05; ES: 0.74-1.40) by 19.6-33.9% only in the HG compared with the CG. Half-squat maximum strength was increased in all experimental groups by 17.4-19% compared with the CG (p < 0.05) with no differences (p > 0.05) observed among them. The use of the optimal height or a moderately higher drop height by 25% for DJ training, combined with weight training, seems to be the most beneficial option to improve vertical jump and reactive strength index in female volleyball players.
... An increase was noted in running speed indices (progress rate = 0.1 sec), aerobic endurance (progress rate = 0.23 sec) and abdominal muscle strength (progress rate = 11.75 repetitions), while the leg muscle strength, although slightly increased (progress rate = 0.12 cm), did not record statistically significant differences between the two tests. These results confirm the findings of other studies conducted with adolescents, which emphasise an improvement in the strength of the upper and lower limbs, speed, flexibility, power and agility through training programmes adapted to the participants" biomotor characteristics (Christou et al., 2006;Kalinowski et al., 2021). ...
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The current study aimed to enhance the level of physical fitness of young football players aged 12-14 years and to verify whether the implementation of a specific motor programmes has positive effects on the development level of general motor skills. This scientific research was intended to make a contribution to the development and assessment of the level of physical fitness of athletes by promoting a set of methods and means for the improvement of physical training process. The research methods used were: literature review, pedagogical observation, verification experiment, mathematical and statistical method, graphical method. The experiment was conducted in the gym of the Middle School no. 13 in Bucharest on a sample of 14 athletes aged 12-14 years and lasted 6 months. Throughout this period, a series of operational structures for the development of physical fitness level were implemented in the training programme. The operational structures were allocated 35 minutes per training session. The study used tests for the assessment of speed, aerobic endurance, explosive power of the lower limbs and abdominal muscle strength. After processing the research results, statistically significant differences have been found between the initial test and the final test, which highlights the efficiency of the methodology used in the physical fitness training optimisation programme. Experimental validation of the methods and means used in the training of the experimental group represents a contribution to increasing the efficiency of the instructive-educational process.
... With a training age of 3 years, he or she may be able to perform 10 repetitions at 75% of 1RM, and as training age increases, the number of repetitions performed at the same percentage decreases even further. [77][78][79][80][81]. ...
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The physical improvements from strength and resistance training have been known for decades, but the cognitive benefits of this type of activity are not as well-known. The aim of this review article is to provide a summary of studies presenting the effects of strength and resistance training on BDNF in healthy young adults. A systematic search of various electronic databases (PubMed, Web of Science, Science Direct and Google Scholar) was conducted in September 2022. Studies that examined associations between strength training and BDNF in healthy young adults aged 18–30 years were included. The final sample included 10 studies published between 2009 and 2020. The results of this literature review are inconclusive. Based on the results of the 10 studies, there is no clear answer as to whether strength training has positive effects on BDNF in healthy young adults.
... To measure agility and anaerobic power, the subjects performed a 10 x 5 m shuttle run test according to the protocol of the Eurofit battery [34,36], followed by a 30-m sprint run from a standing start. Both running tests were conducted on concrete flooring, and the better of two attempts in the shuttle run and the best of the three attempts in 30-m sprint run were used for subsequent analysis. ...
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The effects of genetic polymorphisms on muscle structure and function remain elusive. The present study tested for possible associations of 16 polymorphisms (across ten candidate genes) with fittness and skeletal muscle phenotypes in 17- to 37-year-old healthy Caucasian male endurance (n = 86), power/strength (n = 75) and team athletes (n = 60), and non-athletes (n = 218). Skeletal muscle function was measured with eight performance tests covering multiple aspects of muscular fitness. Along with body mass and height, the upper arm and limb girths, and maximal oxygen uptake were measured. Genotyping was conducted on DNA extracted from blood. Of the 16 polymorphisms studied, nine (spanning seven candidate genes and four gene families/signalling pathways) were independently associated with at least one skeletal muscle fitness measure (size or function, or both) measure and explained up to 4.1% of its variation. Five of the studied polymorphisms (activin- and adreno-receptors, as well as myosine light chain kinase 1) in a group of one to three combined with body height, age and/or group explained up to 20.4% of the variation of muscle function. ACVR1B (rs2854464) contributed 2.0–3.6% to explain up to 14.6% of limb proximal girths. The G allele (genotypes AG and GG) of the ACVR1B (rs2854464) polymorphism was significantly overrepresented among team (60.4%) and power (62.0%) athletes compared to controls (52.3%) and endurance athletes (39.2%), and G allele was also most consistently/frequently associated with muscle size and power. Overall, the investigated polymorphisms determined up to 4.1% of the variability of muscular fitness in healthy young humans.
... Recently, resistance training has been welcomed by children to improve fitness and enhance athletic performance (1). Previous studies have confirmed the effects of resistance exercises on increasing muscular strength (3)(4)(5) and cardiovascular fitness, improving sports performance, bone density, and body composition, and reducing physical damage (6)(7)(8). Strength training is a form of physical fitness that is used to increase the ability to withstand refractory strength (9). ...
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Resistance training is a common component of sports and physical fitness programs for children. Resistance training programs may involve the use of body weight, medical balls, bands and ropes, dumbbells, and barbells. In recent years, researchers have discussed the problems associated with resistance exercises during childhood. A similar view is the impact of these exercises on muscular strength although opinions vary on the role of these exercises on sports performance. Some researchers confirm the effects of resistance training on cardiovascular, bone density, body composition, and physical impairment. However, the main concern of physicians, coaches, and parents is the potential damage caused by these exercises. The present study aimed to reduce the damage caused by resistance training by designing special exercises.
... It has been proven that strength training can significantly improve athletes' vertical jump performance [23,24]. In the present experiment, the vertical jump performance of the HIPT and TRT groups both significantly improved. ...
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Background: High-intensity interval training (HIIT) features short, repeated bursts of relatively vigorous exercise with intermittent periods of rest or low-intensity exercise. High-intensity power training (HIPT), in combination with HIIT and traditional resistance training (TRT), is characterized as multijoint high-intensity resistance exercises with low interset rest periods. HIPT requires people to finish the exercise as fast as possible, which increases acute physiological demands. The aim of the study was to investigate the differences between eight-week HIPT or TRT on exercise performance. Methods: Twenty-four college students were recruited and randomly assigned to either the HIPT or TRT group in a counterbalanced order. The power of upper and lower limbs (50% 1RM bench press and vertical jump) and anaerobic power were tested before and after the training (weeks 0 and 9). The results were analyzed by two-way analysis of variance (ANOVA) or Friedman's test with a significance level of α = 0.05 to compare the effects of the intervention on exercise performance. Results: There were significant differences in the explosive force of the upper and lower limbs between the pretest and post-test in both the HIPT and TRT groups (p < 0.05). However, only the HIPT group showed a significant difference in the mean power on the Wingate anaerobic test between the pretest and post-test (p < 0.05). Conclusions: Both HIPT and TRT can improve upper and lower limb explosive force. HIPT is an efficient training protocol, which took less time and produced a better improvement in mean anaerobic power.
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2 1 ‫ﮐﺎرﺷﻨﺎ‬. ‫داﻧﺸﮑﺪة‬ ‫ورزﺷﯽ،‬ ‫ﻓﯿﺰﯾﻮﻟﻮژي‬ ‫ارﺷﺪ‬ ‫ﺳﯽ‬ ‫ﺗﺮﺑﯿﺖ‬ ‫ﻣﺸﻬﺪ،‬ ‫ﻣﺸﻬﺪ،‬ ‫ﻓﺮدوﺳﯽ‬ ‫داﻧﺸﮕﺎه‬ ‫ورزﺷﯽ،‬ ‫ﻋﻠﻮم‬ ‫و‬ ‫ﺑﺪﻧﯽ‬ ‫ا‬ ‫ﯾﺮان‬ 2 ‫داﻧﺸﮑﺪة‬ ‫ورزﺷﯽ،‬ ‫ﻓﯿﺰﯾﻮﻟﻮژي‬ ‫داﻧﺸﯿﺎر‬. ‫ﺗﺮﺑﯿﺖ‬ ‫اﯾﺮان‬ ‫ﻣﺸﻬﺪ،‬ ‫ﻣﺸﻬﺪ،‬ ‫ﻓﺮدوﺳﯽ‬ ‫داﻧﺸﮕﺎه‬ ‫ورزﺷﯽ،‬ ‫ﻋﻠﻮم‬ ‫و‬ ‫ﺑﺪﻧﯽ‬ ‫ﺗﺎر‬ ‫ﯾ‬ ‫در‬ ‫ﺦ‬ ‫ﯾ‬ ‫ﻣﻘﺎﻟﻪ:‬ ‫ﺎﻓﺖ‬ 26 / 3 / 94 ‫ﺗﺎر‬ ‫ﯾ‬ ‫ﭘﺬ‬ ‫ﺦ‬ ‫ﯾ‬ ‫ﻣﻘﺎﻟﻪ:‬ ‫ﺮش‬ 28 / 1 / 96 ‫ﭼﮑ‬ ‫ﯿ‬ ‫ﺪه‬ ‫ﭘﮋوﻫﺶ:‬ ‫ﻫﺪف‬ ‫ﻣﻄﺎﻟﻌﮥ‬ ‫از‬ ‫ﻫﺪف‬ ‫ﭘﺴﺮ‬ ‫ﺷﻨﺎﮔﺮان‬ ‫اﺟﺮاﻫﺎي‬ ‫ﺑﺮ‬ ‫ﺧﺸﮑﯽ‬ ‫در‬ ‫ﭘﻼﯾﻮﻣﺘﺮﯾﮏ‬ ‫و‬ ‫ﻗﺪرﺗﯽ‬ ‫ﺗﺮﮐﯿﺒﯽ‬ ‫ﺗﻤﺮﯾﻦ‬ ‫ﻫﻔﺘﻪ‬ ‫ﻫﺸﺖ‬ ‫ﺗﺄﺛﯿﺮ‬ ‫ﺗﻌﯿﯿﻦ‬ ‫ﺣﺎﺿﺮ‬ ‫ﻧﺎﺑﺎﻟﻎ‬ 9 ‫ﺗﺎ‬ 12 ‫ﺑﻮد‬ ‫ﺳﺎل‬. ‫ﭘﮋوﻫﺶ:‬ ‫روش‬ ‫آزﻣﻮدﻧﯽ‬ ‫ﭘﮋوﻫﺶ‬ ‫اﯾﻦ‬ ‫ﻫﺎي‬ 20 ‫وزن‬ ‫و‬ ‫ﻗﺪ‬ ‫ﺳﻦ،‬ ‫ﻣﯿﺎﻧﮕﯿﻦ‬ ‫ﺑﺎ‬ ‫ﻧﺎﺑﺎﻟﻎ‬ ‫ﭘﺴﺮ‬ ‫ﺗﺮﺗ‬ ‫ﺑﻪ‬ ‫ﯿ‬ ‫ﺐ‬ 85 / 0 36 / 11 ‫ﺳﺎل،‬ 45 / 7 38 / 148 ‫و‬ ‫ﺳﺎﻧﺘﯿﻤﺘﺮ‬ 51 / 7 05 / 42 ‫ﺑﻮدﻧﺪ‬ ‫ﮐﯿﻠﻮﮔﺮم‬ ‫ﺑﻪ‬ ‫ﮐﻪ‬ ‫ﻏﯿﺮ‬ ‫ﺻﻮرت‬ ‫ﺗﺼﺎدﻓﯽ‬ ‫و‬ ‫ﺷﺮﮐﺖ‬ ‫ﺷﺪﻧﺪ.‬ ‫اﻧﺘﺨﺎب‬ ‫ﻫﺪﻓﻤﻨﺪ‬ ‫ﺑﻪ‬ ‫ﮐﻨﻨﺪﮔﺎن‬ ‫ﺻﻮرت‬ ‫ﮔﺮﻓﺘﻨﺪ.‬ ‫ﻗﺮار‬ ‫ﮐﻨﺘﺮل‬ ‫و‬ ‫ﺗﺠﺮﺑﯽ‬ ‫ﮔﺮوه‬ ‫دو‬ ‫در‬ ‫ﺳﺎده‬ ‫ﺗﺼﺎدﻓﯽ‬ ‫ﺑﺮﻧﺎﻣ‬ ‫ﮥ‬ ‫ﺗﻤﺮ‬ ‫ﯾ‬ ‫ﻨ‬ ‫ﯽ‬ ‫ﺗﻤﺮ‬ ‫ﻓﻘﻂ‬ ‫ﮐﻨﺘﺮل‬ ‫ﮔﺮوه‬ ‫ﯾ‬ ‫ﻨﺎت‬ ‫ﺑﻮد‬ ‫ﺷﻨﺎ‬ ، ‫ﺣﺎﻟ‬ ‫در‬ ‫ﯽ‬ ‫ﮐﻪ‬ ‫ﮔﺮ‬ ‫ﻋﻼوه‬ ‫ﺗﺠﺮﺑﯽ‬ ‫وه‬ ‫ﺷﻨﺎ‬ ‫ﺗﻤﺮﯾﻨﯽ‬ ‫ﺟﻠﺴﺎت‬ ‫ﺑﺮ‬ ، 2 ‫ﺑﺮاي‬ ‫ﻫﻔﺘﻪ‬ ‫در‬ ‫روز‬ 8 ‫ﺗﻤﺮﯾﻦ‬ ‫ﻫﻔﺘﻪ‬ ‫و‬ ‫ﻗﺪرﺗﯽ‬ ‫ﻫﺎي‬ ‫ﺗﻤﺮﯾﻦ‬ ‫دادﻧﺪ.‬ ‫اﻧﺠﺎم‬ ‫را‬ ‫ﭘﻼﯾﻮﻣﺘﺮﯾﮏ‬ ‫ﭘﻼﯾﻮﻣﺘﺮﯾﮏ‬ ‫و‬ ‫ﻗﺪرﺗﯽ‬ ‫ﻫﺎي‬ ‫ﺳﯿﻨﻪ‬ ‫ﭘﺮس‬ ‫ﺷﺎﻣﻞ‬ ، ‫ﻋﻤﻮدي‬ ‫ﭘﺮش‬ ‫زاﻧﻮ،‬ ‫ﺷﺪن‬ ‫ﺑﺎز‬ ، ‫ﭘ‬ ‫و‬ ‫ﻋﻤﻘﯽ‬ ‫ﭘﺮش‬ ‫ﺟﺴﻤﺎﻧ‬ ‫ﻣﺘﻐﯿﺮﻫﺎي‬ ‫ﺑﻮد.‬ ‫ﻃﺒﯽ‬ ‫ﺗﻮپ‬ ‫ﺮﺗﺎب‬ ‫ﯽ‬ ‫ﭘﺎﯾﺎن‬ ‫و‬ ‫ﺷﺮوع‬ ‫در‬ ‫ﻋﻤﻠﮑﺮدي‬ ‫و‬ ‫دورة‬ ‫اﻧﺪ‬ ‫ﺗﻤﺮﯾﻦ‬ ‫ازه‬ ‫داده‬ ‫ﺷﺪﻧﺪ.‬ ‫ﮔﯿﺮي‬ ‫ﻧﺮم‬ ‫ﺗﻮﺳﻂ‬ ‫ﻫﺎ‬ ‫اﻓﺰار‬ SPSS ‫وﯾﺮاﯾﺶ‬ 16 ‫و‬ ‫آزﻣﻮن‬ ‫ﺗﻮﺻﯿﻔﯽ،‬ ‫آﻣﺎر‬ ، ‫ﻣﻦ‬ ‫و‬ ‫ﯾﻠﮑﺎﮐﺴﻮن‬ ‫و‬ ‫ﺗﺠﺰﯾﻪ‬ ‫ﻣﻮرد‬ ‫وﯾﺘﻨﯽ‬ ‫ﮔﺮﻓﺖ.‬ ‫ﻗﺮار‬ ‫ﺗﺤﻠﯿﻞ‬ ‫ﻧﺘﺎﯾﺞ:‬ ‫از‬ ‫ﺑﻌﺪ‬ 8 ‫ﺳﯿﻨﻪ‬ ‫ﮐﺮال‬ ‫ﺷﻨﺎي‬ ‫در‬ ‫ﺟﻠﻮﺑﺮﻧﺪه‬ ‫ﻧﯿﺮوي‬ ‫و‬ ‫ﺷﻨﺎ‬ ‫اﺟﺮاي‬ ‫ﻋﻀﻼﻧﯽ،‬ ‫ﺗﻮان‬ ‫ﻗﺪرت،‬ ‫ﺗﺠﺮﺑﯽ،‬ ‫ﮔﺮوه‬ ‫در‬ ‫ﺗﻤﺮﯾﻦ،‬ ‫ﻫﻔﺘﻪ‬ ‫ﻣﻌﻨﯽ‬ ‫اﻓﺰاﯾﺶ‬ ‫داﺷﺖ‬ ‫داري‬) 05 / 0. (p< ‫ﺳﯿﻨﻪ(‬ ‫)ﭘﺮس‬ ‫ﻗﺪرت‬ ‫ﮐﻨﺘﺮل،‬ ‫ﮔﺮوه‬ ‫در‬ ‫ﺳﯿﻨﻪ‬ ‫ﮐﺮال‬ ‫ﺷﻨﺎي‬ ‫در‬ ‫ﺟﻠﻮﺑﺮﻧﺪه‬ ‫ﻧﯿﺮوي‬ ‫و‬ ‫ﻣﻌﻨﯽ‬ ‫اﻓﺰاﯾﺶ‬ ‫داري‬ ‫داﺷﺖ‬) 05 / 0 .(p< ‫ﻣﻌﻨﯽ‬ ‫ﺗﻔﺎوت‬ ‫ﻫﻤﭽﻨﯿﻦ‬ ‫ﻗﺪرت‬ ‫در‬ ‫داري‬ ، ‫ﺷﻨﺎي‬ ‫اﺟﺮاي‬ ‫و‬ ‫ﻋﻀﻼﻧﯽ‬ ‫ﺗﻮان‬ 25 ‫ﮐﻨﺘﺮل‬ ‫و‬ ‫ﺗﺠﺮﺑﯽ‬ ‫ﮔﺮوه‬ ‫دو‬ ‫ﺑﯿﻦ‬ ‫ﺳﯿﻨﻪ‬ ‫ﮐﺮال‬ ‫ﻣﺘﺮ‬ ‫ﺷﺪ‬ ‫ﻣﺸﺎﻫﺪه‬) 05 / 0. (p< ‫ﮔﯿﺮي:‬ ‫ﻧﺘﯿﺠﻪ‬ ‫ﭘﻼﯾﻮﻣﺘﺮﯾﮏ‬ ‫و‬ ‫ﻗﺪرﺗﯽ‬ ‫ﺗﺮﮐﯿﺒﯽ‬ ‫ﺗﻤﺮﯾﻦ‬ ‫ﻋﻀﻼﻧ‬ ‫ﺗﻮان‬ ‫و‬ ‫ﻗﺪرت‬ ‫اﻓﺰاﯾﺶ‬ ‫ﺑﻪ‬ ‫ﻣﻨﺠﺮ‬ ‫ﻧﺎﺑﺎﻟﻎ‬ ‫ﺷﻨﺎﮔﺮان‬ ‫در‬ ‫ﯽ‬ ‫ﻣﯽ‬ ‫ﺷﻮد.‬ ‫اﮔﺮ‬ ‫ﺑﻬﺒﻮد‬ ‫ﭼﻪ‬ ‫ﺷﻨﺎي‬ ‫اﺟﺮاي‬ 25 ‫ﻧﮑﺘﮥ‬ ‫ﺳﯿﻨﻪ‬ ‫ﮐﺮال‬ ‫ﻣﺘﺮ‬ ‫داده‬ ‫اﻣﺎ‬ ‫اﺳﺖ،‬ ‫ﺗﻮﺟﻬﯽ‬ ‫ﻗﺎﺑﻞ‬ ‫ﺑﻪ‬ ‫ﻫﺎ‬ ‫اﯾﻦ‬ ‫ﮐﻪ‬ ‫اﺳﺖ‬ ‫اﯾﻦ‬ ‫ﺑﯿﺎﻧﮕﺮ‬ ‫روﺷﻨﯽ‬ ‫ﺗﻤ‬ ‫ﮔﻮﻧﻪ‬ ‫ﺮﯾﻨﺎت‬ ‫ﻧﻤﯽ‬ ‫ﺟﻠﻮﺑﺮﻧﺪه‬ ‫ﻧﯿﺮوي‬ ‫و‬ ‫ﺷﻨﺎ‬ ‫اﺟﺮاي‬ ‫اﻓﺰاﯾﺶ‬ ‫ﺑﻪ‬ ‫ﻣﻨﺠﺮ‬ ‫ﺷﻮد.‬ ‫ﮐﻠﯿﺪ‬ ‫واژه‬ ‫ﻫﺎ:‬ ‫ﺟﻠﻮﺑﺮﻧﺪه‬ ‫ﻧﯿﺮوي‬ ‫ﺷﻨﺎ،‬ ‫اﺟﺮاي‬ ‫ﺗﻮان،‬ ‫ﻗﺪرت،‬ Abstract Purpose: There is clear evidence that resistance training can be a worthwhile and beneficial activity for children. The purpose of the present study was to determine the effect of eight weeks combined strength and plyometric training on land in performances of 9-12 years old male swimmers. Methods: Our participants include; 20 boys with mean age, height and weight of 11.36±0.85 yr, 148.38±7.45 cm and 42.05±7.51 kg respectively. Our sample was selected by purposefully non-random method then randomly divided to experimental and control group. Training program of control group was limited to swimming practice sessions while; the experimental group in addition to swimming training sessions, they conducted strength and plyometric training two days weekly for eight weeks. The strength and plyometric exercises include: bench press, leg extension, vertical jump, depth jump and medicine ball throwing. Physical and performance variables were measured at the beginning and at the end of the training period. The data were analyzed using SPSS (version 16) with Descriptive Statistics, Wilcoxon and Mann-Whitney U tests. Results: After 8 weeks of training, in the experimental group, strength, muscular power, swimming performance and propulsive force in front crawl swimming significantly increased (p <0.05). In the control group, strength bench press and propulsive force in front crawl swimming significantly increased (p <0.05). Significant differences in strength, muscular power and swimming performance in 25 m front crawl between experimental and control groups were also observed (p <0.05). Conclusions: A combined strength and plyometric training allow strength and muscular power developments in young male swimmers. Although swimming performance improvement in 25 m front crawl due to strength training was noticeable but these current results do not clarify that these training programs can enhance swimming performance and propulsive force.
Conference Paper
INTRODUCTION: In the last decade foam rolling has become a popular technique in sports practice (1). A recent meta-analysis showed that a single foam rolling exercise can acutely increase the range of motion (ROM) of a joint (2). However, evidence on the training effects of foam rolling on joint ROM, is limited and inconsistent (3,4). Hence, there is a need to conduct a meta-analysis on the long-term training effects of foam rolling on ROM. Therefore, the purpose of this meta-analysis was to investigate the effects of foam rolling training interventions on joint ROM in healthy participants. METHODS: For the main meta-analysis we applied a random-effect model, whilst subgroup analyses were performed by applying a mixed-effect model. Subgroups included comparisons of the intervention total load (i.e., time under tension; ≤ 1520s vs. > 1520s), duration (≤4 weeks vs. >4weeks), comparisons between muscles tested (e.g., hamstrings vs. quadriceps vs. triceps surae), and study designs (RCT vs. CT). RESULTS: In total 11 studies with 46 effect sizes were included in this meta-analysis. The main meta-analysis revealed a moderate effect of foam rolling training on ROM increases in the foam rolling group compared to the control group (ES = 0.823; Z = 3.237; CI (95%) 0.325 to 1.322; p = 0.001; I2 = 72.76). Subgroup analyses showed a significant difference in the intervention duration in favor of interventions >4 weeks compared to ≤4 weeks for ROM increases (p=0.049). Moreover, a further subgroup analysis showed significant differences between the muscles tested (p=0.047). While foam rolling increased joint ROM when applied to hamstrings and quadriceps, no such increase was observed in ankle dorsiflexion ROM after triceps surae rolling. CONCLUSION: Our meta-analysis showed that a longer duration (i.e., > 4 weeks) foam rolling intervention can increase joint ROM in young healthy participants. However, ROM increases may be muscle-and/or joint dependent as foam rolling on the triceps surae muscle did not increase ankle dorsiflexion ROM. Although not much evidence, it is assumed that altered pain perception is a possible mechanism for long-term increases in ROM after a foam rolling intervention rather than changes in soft tissue stiffness (3). REFERENCES: 1. Behm D. et al. (2020) Foam Rolling Prescription: A Clinical Commentary. J. strength Cond. Res. 34:3301–3308 2. Hodgson D. et al. (2018) Four weeks of roller massage training did not impact range of motion, pain pressure threshold, voluntary contractile properties or jump performance. Int J Sports Phys Ther 13:835–845. 3. Kiyono R. et al. (2020) Effects of 5-Week Foam Rolling Intervention on Range of Motion and Muscle Stiffness. J Strength Cond Res 4. Wilke J. et al. (2020) Acute Effects of Foam Rolling on Range of Motion in Healthy Adults: A Systematic Review with Multilevel Meta-analysis. Sport Med 50:387–402.
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Purpose: There is clear evidence that resistance training can be a worthwhile and beneficial activity for children. The purpose of the present study was to determine the effect of eight weeks combined strength and plyometric training on land in performances of 9-12 years old male swimmers. Methods: Our participants include; 20 boys with mean age, height and weight of 11.36±0.85 yr, 148.38±7.45 cm and 42.05±7.51 kg respectively. Our sample was selected by purposefully non-random method then randomly divided to experimental and control group. Training program of control group was limited to swimming practice sessions while; the experimental group in addition to swimming training sessions, they conducted strength and plyometric training two days weekly for eight weeks. The strength and plyometric exercises include: bench press, leg extension, vertical jump, depth jump and medicine ball throwing. Physical and performance variables were measured at the beginning and at the end of the training period. The data were analyzed using SPSS (version 16) with Descriptive Statistics, Wilcoxon and Mann- Whitney U tests. Results: After 8 weeks of training, in the experimental group, strength, muscular power, swimming performance and propulsive force in front crawl swimming significantly increased (p <0.05). In the control group, strength bench press and propulsive force in front crawl swimming significantly increased (p <0.05). Significant differences in strength, muscular power and swimming performance in 25 m front crawl between experimental and control groups were also observed (p <0.05). Conclusions: A combined strength and plyometric training allow strength and muscular power developments in young male swimmers. Although swimming performance improvement in 25 m front crawl due to strength training was noticeable but these current results do not clarify that these training programs can enhance swimming performance and propulsive force.
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This study examined the effects of training frequency on strength maintenance in 21 trained pubescent male baseball players (mean age 13.25 +/- 1.26 yrs). The subjects completed 12 weeks of preseason, progressive strength training 3 days a week and were assigned to 1 of 3 experimental groups for an additional 12 weeks of in-season maintenance training. Group 1 (n = 7) lifted weights 1 day a week, Group 2 (n = 8) lifted weights 2 days a week, and a control group (n = 6) did not train during this 2nd 12 weeks. The preseason strength training program revealed significant increases (p < 0.05) for all groups in upper (bench press) and lower (leg press) body strength and dynamic upper body muscular endurance (pull-up). Following the 12-week in-season maintenance program, significant differences (p < 0.05) were observed between the control group and both training groups for the bench press. However, no significant differences were revealed between groups for the leg press or pull-up. It was concluded that for pubescent male athletes, a 1-day-a-week maintenance program is sufficient to retain strength during the competitive season. (C) 1996 National Strength and Conditioning Association
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The purpose of the present study was to determine the effect of a 12-week training program on the motor performance of 6- to 8-year-old prepubertal boys (n = 14). Each subject participated in a 40-min session twice a week, which included three sets of upper body strength exercises (1 to 15 repetitions/ set), unregimented lower body strength exercises, coordination, balance, and martial arts skills. The control group included 15 prepubertal boys in the same age range. All subjects were pre- and posttested on 20-s sit-ups, seated ball put, standing broad jump, sit-and-reach flexibility, 6 × 4-m shuttle run, and a coordination task. The experimental group improved significantly (p < .05) more than the control group in the sit-ups and in the long jump. Both groups improved (p < .05) in the coordination task. No significant changes were observed in body weight, seated ball put, flexibility, and shuttle run. A twice-weekly training program seems to improve performance in selected motor tasks in 6- to 8-year-old boys.
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The effectiveness of a twice-a-week strength training program on children was evaluated in 14 boys and girls (mean age 10.8 yrs) who participated in a biweekly training program for 8 weeks. Each subject performed three sets of 10 to 15 repetitions on five exercises with intensities ranging between 50 and 100% of a given 10-repetition maximum (RM). All subjects were pre- and posttested on the following measures: 10-RM strength, sit and reach flexibility, vertical jump, seated ball put, resting blood pressure, and body composition parameters. The subjects were compared to a similar group of boys and girls (n = 9; mean age 9.9 yrs) who were randomly selected to serve as controls. Following the training period, the experimental group made greater gains in strength (74.3%) as compared to the control group (13.0%) (p < 0.001), and differences in the sum of seven skinfolds were noted (−2.3% vs. +1.7%, respectively, p < 0.05). Training did not significantly affect other variables. These results suggest that parti...
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This abridged version of the "Anthropometric Standardisation Reference Manual" contains the heart of the original manual - complete procedures for 45 anthropometric measurements. Its style enables it to be used as a supplemental text for courses in fitness assessment and exercise prescription, kinanthropometry, body composition, nutrition, and exercise physiology. It can also be used as a reference for exercise scientists. For each of the 45 measurements included in this abridged edition, readers will find complete information on the recommended technique for making the measurement, the purpose and uses for the measurement, the literature on which the measurement technique is based, and the reliability of the measurement.
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