agility in sub elite -under 11 soccer players saq

Research in Sports Medicine
An International Journal
ISSN: 1543-8627 (Print) 1543-8635 (Online) Journal homepage: http://www.tandfonline.com/loi/gspm20
Agility profile in sub-elite under-11 soccer players:
is SAQ training adequate to improve sprint,
change of direction speed and reactive agility
performance?
Athos Trecroci, Zoran Milanović, Alessio Rossi, Marco Broggi, Damiano
Formenti & Giampietro Alberti
To cite this article: Athos Trecroci, Zoran Milanović, Alessio Rossi, Marco Broggi, Damiano
Formenti & Giampietro Alberti (2016): Agility profile in sub-elite under-11 soccer players:
is SAQ training adequate to improve sprint, change of direction speed and reactive agility
performance?, Research in Sports Medicine, DOI: 10.1080/15438627.2016.1228063
To link to this article: http://dx.doi.org/10.1080/15438627.2016.1228063
Published online: 03 Sep 2016.
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Date: 09 September 2016, At: 02:54
RESEARCH IN SPORTS MEDICINE, 2016
http://dx.doi.org/10.1080/15438627.2016.1228063
Agility profile in sub-elite under-11 soccer players: is SAQ
training adequate to improve sprint, change of direction
speed and reactive agility performance?
Athos Trecrocia, Zoran Milanovićb, Alessio Rossia, Marco Broggia, Damiano Formentia
and Giampietro Albertia
a
Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy; bFaculty of
Sport and Physical Education, University of Nis, Nis, Serbia
ABSTRACT
ARTICLE HISTORY
The purpose of this study was to examine the effects of speed,
agility and quickness (SAQ) training on acceleration (5 and 20 m),
change of direction speed (CODS) and reactive agility in preadolescent soccer players. Thirty-five participants (age = 10.57 ± 0.26,
body mass = 36.78 ± 5.34 kg, body height = 1.42 ± 0.05 m),
randomly assigned to experimental (EG, n = 20) and control
groups (CG, n = 15), completed a 12-week training intervention,
2 day/week. A significant interaction was found in 5-m sprint
(P < 0.05, part η2 = 0.117) and reactive agility (P < 0.01, part
η2 = 0.248) between EG and CG. In both groups, 20-m sprint
time improved significantly (P < 0.05, effect size = 0.3–0.4) while
performance on CODS remained unchanged after 12 weeks. These
findings indicated that SAQ training could positively affect cognitive skills and initial sprint acceleration through the middle childhood, offering useful guidance to soccer coaches.
Received 27 March 2016
Accepted 14 August 2016
KEYWORDS
Athletic performance;
complex training; physical
activity; planning; youth
Introduction
Speed, agility and quickness (SAQ) are important determinants of the soccer anaerobic
fitness that allow players to address successfully crucial moments (e.g. winning ball
possession, dribbling an opponent and/or scoring a goal) throughout the match
(Hammami, Makhlouf, Chtara, Padulo, & Chaouachi, 2015). However, these determinants
are characterized by diverse physiological and biomechanical factors (Little & Williams,
2005) and their individual training would produce limited transfer to each other (Young,
McDowell, & Scarlett, 2001). Since soccer performance depends on multidimensional
physical demands (Bangsbo, Mohr, & Krustrup, 2006) based on open (e.g. reaction tasks)
and closed skill activities (e.g. change of direction speed [CODS]) (Gabbett, Sheppard,
Pritchard-Peschek, Leveritt, & Aldred, 2008; Ibba et al., 2014; Padulo et al., 2014, 2015,
2015; Trecroci, Cavaggioni, Caccia, & Alberti, 2015), it would be conceivable using
training methods aimed to promote integrated effects of SAQ at improving
CONTACT Athos Trecroci
[email protected]
Department of Biomedical Sciences for Health, Università
degli Studi di Milano, Via G. Colombo, 71, 20133 Milan, Italy
© 2016 Informa UK Limited, trading as Taylor & Francis Group
2
A. TRECROCI ET AL.
physiological and biomechanical adaptations, thus, saving energy and time (Jovanovic,
Sporis, Omrcen, & Fiorentini, 2011).
In this context, the SAQ training method refers to a training approach combining
high rate of movement tasks performed in a brief amount of time (quickness) and both
straight (speed) and multidirectional sprints over different distances with and without
cognitive stimuli (agility) that has become popular within soccer-related literature
(Bloomfield, Polman, O’Donoghue, & McNaughton, 2007; Jovanovic et al., 2011;
Milanović, Sporiš, Trajković, James, & Šamija, 2013; Milanović et al., 2014; Polman,
Walsh, Bloomfield, & Nesti, 2004).
Previous studies showed significant improvements in the 5- and 10-m sprint tests,
reporting that SAQ training was an effective tool for improving sprint performance up to
10 m (Jovanovic et al., 2011; Milanović et al., 2014). In addition, after a 12-week SAQ
training programme, Milanović et al. (2013) observed a significant enhancement in the
CODS with and without ball among under-19 soccer players. A further study investigated the effects of different SAQ training approaches on elite female athletes (Polman
et al., 2004). Polman et al. (2004) have showed that SAQ training using either specialized
(e.g. speed-ladder, hurdles, reaction balls and resistance cords) or non-specialized equipment (e.g. traditional soccer coaching equipment) produced similar effects after 12-week
training programme. The two approaches led to greater improvements in sprint, CODS
performance and vertical and horizontal jump tasks compared to regular soccer-specific
training. They concluded that SAQ training seemed to be an appropriate physical
conditioning element for young adult female soccer players.
Despite well-established advantages of using an integration of SAQ activities in
young adults and adolescents, to date, no studies have been conducted on younger
athletes. Preadolescent soccer players experience various exercises similar to those
incorporated in the SAQ method within their regular training sessions. For example,
during the sampling stage (from age 6 to 12 years), young athletes engage with both
deliberate and non-deliberate practice (e.g. age-adapted game formats and technical
drills) that contain rapid multi-directional steps, accelerations, decelerations, turnings, as
well as cognitive stimuli provided by unpredictable actions of soccer-related games
(Trecroci et al., 2015). According to Fransen et al. (2012), sampling stage is considered
beneficial for athletic and perceptual development in young athletes. Thus, training
methods including a combination of physical and cognitive drills (i.e. SAQ training) may
be more effective for middle childhood than adulthood (Fransen et al., 2012).
Therefore, the aim of this study was to investigate the effectiveness of a 12-week SAQ
training programme on acceleration, CODS and reactive agility profile in sub-elite under11 soccer players. We hypothesized that training based on SAQ would be more effective
than a mere sport-specific training for improving acceleration, CODS and reactive agility
in preadolescent soccer players.
Materials and methods
Participants
Thirty-nine sub-elite young soccer players were recruited for the study and randomly
divided in two groups using a random allocation table by means of which it was
RESEARCH IN SPORTS MEDICINE
3
generated an unpredictable random sequence for assigning participants to experimental
(EG) and control groups (CG). Twenty players were allocated in the EG (age:
10.5 ± 0.30 years; body mass: 37.94 ± 6.00 kg; height: 1.42 ± 0.05 m; body mass index
[BMI]: 18.05 ± 2.11 kg/m2; maturity offset: −2.58 ± 0.15; soccer training experience:
3.50 ± 0.66 years), while 19 players were allocated in the CG (age: 10.7 ± 0.21 years;
body mass: 35.24 ± 3.98 kg; height: 1.42 ± 0.06 m; BMI: 16.86 ± 1.30 kg/m−2; maturity
offset: −2.48 ± 0.10; soccer training experience: 3.41 ± 0.55 years). Unfortunately, four
participants of the CG dropped out prior to conclude the study for external reasons. All
players and their parents were informed about the purpose and experimental protocol
of the study. Parents or legal guardians provided the written informed consent before
the investigation. In accordance with the Declaration of Helsinki, the study was
approved by the ethics committee of the local University.
Procedures
All participants underwent a 4-week (two sessions per week) familiarization period
before starting the training intervention (Figure 1). Anthropometric characteristics
including height and weight were measured using a stadiometer (SECA 213, Germany)
and a portable scale (SECA 813, Germany) to the nearest 1.0 cm and 0.1 kg 48 h prior to
testing; with this data, we also calculated the BMI and the maturation index of the
players. This index was calculated by the following redeveloped equation of Moore et al.
(2015): maturity offset = −7.999994 + (0.0036124 × [age × height]) with R2 = 0.896, and
the standard error of estimated = 0.542. Within testing session, 5- and 20-m sprint tests
were selected to assess first-steps acceleration and speed characteristics of each participant. While, modified Illinois change of direction and reactive agility tests were
included to detect participant’s ability to change direction under several pattern of
movements as well as to react to visual stimuli provided by a live opponent. To evaluate
test–retest reliability, all participants were tested on an artificial turf wearing soccer
shoes in two separated days with at least 48 h in between. All tests were randomly
performed at the same time of day (from 5 to 7 p.m.) for pre- and post-test sessions. A 5min warm-up period consisting of general running exercises (e.g. jogging forwards and
backwards) and dynamic stretching (e.g. “knee to chest” and “high kicks” exercises)
preceded each test, while 10-min of rest was given among tests. A photocells timing
Figure 1. The training programme design.
4
A. TRECROCI ET AL.
system (Polifemo Radio, 0.125-ms resolution, Microgate, Bolzano, Italy) was used to
record split completion times, and the timing gates were placed at 0.70 m above the
ground. Fastest trial for each turn was included in the analysis.
Trials for 5- and 20-m sprint tests
On command, participants performed three trials of 20-m sprint (0–5, 0–20 m intervals)
starting from a standing position. To prevent fatigue-induced effects, a recovery of 3 min
was given among trials.
Modified Illinois change of direction test (MICODT)
A MICODT was used to assess CODS profile among different patterns of movement
including sprints, directional changes, turnings and slalom runs (Hachana et al., 2014).
On command, from a standing position, participants ran from point A to point B as
shown in Figure 2(a). They performed three trials resting 3 min in-between. Participants
were also instructed not to cut over the cones but to move around without touching or
hitting them. In case of failure, the trial was repeated after an extra recovery (~1 min).
Reactive agility test (RAT)
The RAT used in this study referred to the similar Y-shaped agility test previously
adopted by other authors (Green, Blake, & Caulfield, 2011; Oliver & Meyers, 2009;
Veale, Pearce, & Carlson, 2010) and including a live experimenter. After an initial sprint,
participants were required to react to the left or to the right gates according to the
experimenter’s movements: (i) step forward with the right or left foot, and change
direction to the left or right, respectively; (ii) step forward with the right or left, then
left or right, and change direction to the right or left, respectively. All participants were
Figure 2. (a) Layout of the Modified Illinois Change of Direction Test (MICODT); (b) Schematic
representation of the reactive agility test (RAT) with the addition of a live experimenter.
RESEARCH IN SPORTS MEDICINE
5
asked not to anticipate the reaction [Figure 2(b)]. Four trials were executed in a
randomized order with 2 min of rest in-between.
Training intervention
The intervention programmes involved 12-weeks in-season period from the beginning
of March until the end of May consisting in 24 training sessions, 2 days/week separated
by at least 48 h. Each intervention lasted 25 min, and it was given at the beginning of
the training session after an 8-min warm up with slow running and dynamic stretching
(Chaouachi et al., 2015). The SAQ-training programme consisted of brief efforts (from 3
to 5 s) in the form of SAQ drills (Table 1) arranged in two phases interspersed by 5 min of
rest. Both phases lasted 10 min and matched for number of drills, work volume/drill and
rest between drills (Table 2). Each experimental training session was organized in four
stations for every single drill with an equal number of participants (five per group) to
maintain the intensity as high as possible (Dawes, Roozen, & National Strength &
Conditioning Association, 2012). Participants commenced each station one after the
other with an approximately work:rest ratio of 1:2 during a single repetition. A supervisor with years of experience in strength and conditioning coaching monitored the
entire execution, providing verbal encouragement and technical support.
The CG performed soccer-specific drills also arranged in two phases for the same
amount of time of the EG (i.e. 25 min). The first phase included high-intensity technical
circuits (e.g. relay race including ball carrying, passing, heading, and dribbling drills)
while the second phase included progressive evasion drills with a combination of
defensive and offensive maneuvers (1 on 1, 2 on 1, 2 on 2 and 3 on 2) over the 12
Table 1. Descriptive characteristics of the 12-week SAQ training intervention performed by the EG.
SAQ intervention
Weeks
Week 1 and 2
Week 3–5
Week 6–8
Week 9–12
First phase
Second phase
Quickness and agility
Foot-working exercises using hoops (e.g. split
steps, line drills, lateral line hops and
multiple hops)
Speed-ladder exercises with a combination of
basic drills (e.g. one/two in the hole, skipping
and hopscotch)
Speed-ladder exercises with a combination of
advanced drills (e.g. carioca, cha-cha, cherry
pickers and slaloms)
Speed-ladder exercises in combination with
agility drills (e.g. reaction to a visual stimulus)
Speed, CODS and agility
Brief sprints with few directional changes
(e.g. from 1 to 3) and different angles
(30° and 45°)
Brief sprints with several directional
changes (e.g. from 3 to 5) and different
angles (30°, 45° and 90°)
Agility drills in response to different
commands (e.g. colour tag, right-to-left
direction)
Agility drills with an opponent (e.g.
chasing runs, “mirror” drills)
SAQ: speed, agility and quickness, CODS: change of direction speed.
Table 2. Framework of a single SAQ training session.
SAQ programme
SAQ training
session
No. of
drills
Work volume/
drill (s)
Rest between drills/
exercise (s)
Single phase
duration (min)
Rest between
phases (min)
First phase
Second phase
4
4
120
120
30
40
10
10
5
SAQ: speed, agility and quickness.
6
A. TRECROCI ET AL.
weeks, two sessions per week. As for the SAQ session, all exercises were conducted with
a work:rest ratio of 1:2 during each repetition.
Statistical analyses
Test–retest reliability was assessed for 5- and 20-m sprint tests, MICODT and RAT using a
one-way intra-class correlation coefficient (ICC) based on average measurements (ICC 1,
k). According to the normality assessed by Shapiro-Wilks’ test, unpaired t-tests were used
to detect difference between EG and CG in anthropometric characteristics and in pretraining test evaluations. Changes in sprint, CODS and reactive agility of both groups
were analysed using a two-way analysis of variance (ANOVA) repeated measures on one
factor (e.g. time). Effect size (ES) was calculated for multiple comparisons to determine
the magnitude of the pre–post changes. ES were classified as follows: <0.2 was defined
as trivial, 0.2–0.6 was defined as small, 0.6–1.2 was defined as moderate, 1.2–2.0 was
defined as large, and >2.0 was defined as very large (Hopkins, Marshall, Batterham, &
Hanin, 2009). The level of significance was set at P < 0.05, and data were shown as mean
± SD. Statistical analysis was performed using SPSS 21.0 for windows (IBM SPSS Statistics,
Inc., New York, NY, USA).
Results
Both EG and CG presented non-significant differences for age, anthropometric characteristics and overall performance variables at the pre-training (P > 0.05). A good
level of test–retest reliability was attained for 5- and 20-m sprint tests (ICC = 0.88,
ICC = 0.92), and for MICODT and RAT (ICC = 0.88, ICC = 0.85), respectively. Significant
interactions were found in 5-m sprint test (F1,33 = 4.738, P = 0.044, part η2 = 0.117)
and RAT (F1,33 = 10.889, P = 0.002, part η2 = 0.248). The EG, compared to the CG,
obtained greater pre–post changes in both tests as showed by the ES (Table 3). A
within-subjects difference was observed in the 20-m sprint test (F1,33 = 11.372,
P = 0.002, part η2 = 0.256) in both groups (Table 3). The CODS measured by
MICODT remained unchanged for both EG and CG after the intervention
(F1,33 = 1.399, P = 0.245, part η2 = 0.041).
Table 3. Differences in sprint, change of direction speed and reactive agility after 12-week training
programme (mean ± SD).
EG (N = 20)
5-m sprint test (s)*
20-m sprint test (s)ǂ
MICODT (s)
RAT (s)*
Pre
1.53 ± 0.08
4.27 ± 0.24
13.35 ± 0.66
2.85 ± 0.15
Post
1.50 ± 0.08
4.16 ± 0.26
13.4 ± 0.52
2.73 ± 0.15
CG (N = 15)
(%)
2.0
2.6
0.4
4.2
ES
0.4
0.4
0.0
0.8
Pre
1.49 ± 0.07
4.11± 0.22
13.10 ± 0.69
2.78 ± 0.19
Post
1.50 ± 0.09
4.05 ± 0.23
13.08 ± 0.68
2.75 ± 0.19
(%)
0.7
1.5
0.2
1.1
ES
0.1
0.3
0.0
0.2
Interaction: *P < 0.05; within-subjects factor: ǂP < 0.05.
MICODT: Modified Illinois Change of Direction Test, RAT: reactive agility test, ES: effect size, EG: experimental groups,
CG: control group, % = per cent change in performance.
RESEARCH IN SPORTS MEDICINE
7
Discussion
The main findings of this study indicated that a 12-week SAQ training programme
improved significantly 5-m sprint and RAT performance in preadolescent soccer players
compared to a mere soccer training. The ability to perform maximal running tasks over
short distances is considered an essential component of the running performance
during matches (Dawes et al., 2012; Tomáš, František, Lucia, & Jaroslav, 2014). The
significant improvement observed on 5-m sprint may be attributed to the specificity
of foot-working exercises (e.g. split steps, skipping and multiple hops) conducted by the
EG, which were based on short contact times with the surface. This condition can elicit
to higher forces production at faster rates, resulting in an increase in power (Bloomfield
et al., 2007). It has been shown that 10–11-year-old children may be largely benefited by
explosive activities (based on rapid stretch-shortening cycle) improving their sprint time
because of high neuromuscular adaptations (e.g. intra- and intramuscular coordination)
(Michailidis et al., 2013). Similar improvements were also reported on sprint performance
up to 15 m in other studies in adolescent and young adult athletes, supporting the use
of SAQ method for enhancing acceleration in soccer (Bloomfield et al., 2007; Jovanovic
et al., 2011; Milanović et al., 2014). Hence, in this study, it can be speculated that 5-m
sprint improvements could be due to a gain in stretch-shortening cycle ability via
improved intra- and intermuscular coordination in the first steps (Trecroci et al., 2015).
In light of this, the present result might have implication throughout a match by
increasing the chance of players to win one-on-one duels, or successfully defending
an attack. To the best of the author’s knowledge, this is the first study assessing the
effects of SAQ training on reactive agility in preadolescent soccer players. Addressing
decision-making demands during the sampling stage becomes crucial to youth athletic
development at improving reaction skills. The present results showed a moderate effect
on the total time of the RAT performance in the EG (P < 0.05). This finding may be likely
due to the integrated effects provided by agility drills in response to an opponent (e.g.
chasing runs) and different commands (e.g. right-to-left directions) based on non-sport
specific stimuli. Accordingly, a recent large-sampled study on 553 subjects has monitored reaction time along age in response to non-task specific stimuli (Zemková &
Hamar, 2014). The participants had to touch four mats located at the corners of a
0.55-m square according to visual stimuli (rear right or left and front right or left)
generated by a computer screen. Zemková and Hamar (2014) observed greater improvements, from ages 7 to 14 compared to older, in which the size of such positive trend
appeared smaller along age. As a result, the authors stated that reaction skills based on
general perceptual components would be effectively trainable in the middle childhood.
The latter consideration seems to be consistent with the results found in the CG. At the
end of the 12-week intervention, RAT improvements of the CG were negligible (P > 0.05)
with a small estimated ES. It is reasonable thinking that the little soccer training background of the participants (<4 years) may have limited positive transfer of highly sportspecific stimuli by evasive drills performed in the study.
The ability to rapidly decelerate, change body direction and accelerate in a planned
context (e.g. CODS) is an important prerequisite in the soccer-related tasks that has to be
trained as well as monitored throughout a season (Young & Rogers, 2014). After 12
weeks of training, however, CODS profile measured by MICODT remained unchanged in
8
A. TRECROCI ET AL.
both groups. A plausible explanation can be given by the fact that CODS trainability is
associated with the prepubertal spurt, achieving its peak rate of development approximately at 13–14 years of age (Lloyd et al., 2013). Thus, potential neuromuscular adaptations derived from SAQ training may not have been adequate enough to affect CODS
performance in under-11 soccer players of this study. This seems to support the fact that
focusing on CODS development in the prepubescent may not be a primary aim of youth
training programmes as reported previously (Lloyd et al., 2013).
With regard to the speed assessment, both EG and CG exhibited a significant
improvement in the 20-m sprint time with a small effect (0.2 < ES < 0.6) after 12
weeks. This result is in contrast with those reported in literature for older athletes in
which no performance gains were observed on 20-m sprint after SAQ training (Jovanovic
et al., 2011; Milanović et al., 2014). In fact, these authors observed that increases in sprint
performance via SAQ method were effective solely over short distances (i.e. 0–5 m)
because of the specificity of movement patterns over short distance.
However, as the present ES were small for both groups, it is conceivable that
performance gains observed on 20-m sprint were due to other factors rather than a
training effect. In fact, concurrent small ES detected in both groups may be likely the
result from a natural nervous system development, which is known to be dominant
within the sampling years (Ostojic et al., 2014).
As far as the authors are concerned, this study presents a limitation that has to be
considered. In the RAT, the total time was the only variable taken into account to
evaluate participants’ response rather than decision time. In fact, although both time
variables are correlated (Young & Willey, 2010), one may argue that positive effects in
the RAT would be the result of an improvement in the 5-m sprint rather than in decisionmaking factors. However, if that were true, we would have also expected an improvement in the MICODT. Nonetheless, further studies should be encouraged to introduce
high-speed video recordings to identify all of the time variables affecting reactive agility
performance in the attempt to corroborate or not our results.
Conclusions
SAQ training method appeared to be more effective at improving acceleration over 5 m
and reactive agility than a soccer-specific training programme in preadolescent soccer
players. From a practical point of view, our novel findings indicated that the agility
profile can be successfully improved in the middle childhood through organized SAQ
drills. On the contrary, SAQ training seemed not be adequate for enhancing speed and
CODS performance in the same period.
Acknowledgement
The authors would like to thank Luca Rimoldi (M.Sc.) for his technical support.
Disclosure statement
No potential conflict of interest was reported by the authors.
RESEARCH IN SPORTS MEDICINE
9
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