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Background: It is unknown whether a concentrated period of small-sided games and high intensity training is an effective training approach in youth soccer players. The aim of the study was to examine the effect of a concentrated period of soccer specific training on physical fitness in youth players. Methods: Nineteen male soccer players, from two teams, participated (mean ± SD age: 16.2 ± 0.8 years; body mass: 58.2 ± 7.6 kg; height: 170.8 ± 7.7 cm). One team performed 5 days of small-sided games and high intensity training (SSG & HIT; n = 12) and the other team regular soccer training with 1 day of SSG and HIT (REG; n = 7) weekly for 4 weeks. The 30-15 intermittent fitness test (30-15 IFT), countermovement jump (CMJ) and change of direction (COD) performance were measured pre and post intervention. Heart rate (HR) and rating of perceived exertion (RPE) were recorded and session load calculated (RPE x minutes). Results: Average % of maximum HR and session load were 83% and 344 AU for the SSG & HIT vs 73% and 253 AU for the REG (P< 0.05). 30-15 IFT improved for the SSG & HIT (from 17.0 ± 1.1 to 18.4 ± 0.8 km/h; p< 0.05; ES = 0.57) with no difference for the REG group (Pre: 17.9 ± 1.3, Post: 18.2 ± 1.6 km/h, ES= 0.10). CMJ and COD were unchanged in both groups and no injuries were reported. Conclusions: A 4-week concentrated period of daily SSG & HIT is effective for improving endurance performance in youth soccer players. This was without injuries and without negating performance in power and change of direction.
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J Sports Med Phys Fitness. 2018 Jun 27. doi: 10.23736/S0022-4707.18.08547-X. [Epub
ahead of print]
Title: The effect of a concentrated period of soccer specific fitness training with small-sided
games on physical fitness in youth players
Authors
Darren J. Paul1, Joao B. Marques1, George P. Nassis1*
Affiliations
1National Sports Medicine Programme, Excellence in Football Project, Aspetar - Orthopedic
and Sports Medicine Hospital, Sports City, 29222 Doha, Qatar.
*Corresponding Author: George P. Nassis, PhD, georgenassis@gmail.com
Running title: Concentrated training in soccer
Abstract
BACKGROUND: It is unknown whether a concentrated period of small-sided games and
high intensity training is an effective training approach in youth soccer players. The aim of
the study was to examine the effect of a concentrated period of soccer specific training on
physical fitness in youth players. METHODS: Nineteen male soccer players, from two teams,
participated (mean ± SD age: 16.2 ± 0.8 years; body mass: 58.2 ± 7.6 kg; height: 170.8 ± 7.7
cm). One team performed 5 days of small-sided games and high intensity training (SSG &
HIT; n = 12) and the other team regular soccer training with 1 day of SSG and HIT (REG; n
= 7) weekly for 4 weeks. The 30-15 intermittent fitness test (30-15 IFT), countermovement
jump (CMJ) and change of direction (COD) performance were measured pre and post inter-
vention. Heart rate (HR) and rating of perceived exertion (RPE) were recorded and session
load calculated (RPE x minutes). RESULTS: Average % of maximum HR and session load
were 83% and 344 AU for the SSG & HIT vs 73% and 253 AU for the REG (P< 0.05). 30-
15 IFT improved for the SSG & HIT (from 17.0 ± 1.1 to 18.4 ± 0.8 km/h; p< 0.05; ES =
0.57) with no difference for the REG group (Pre: 17.9 ± 1.3, Post: 18.2 ± 1.6 km/h, ES=
0.10). CMJ and COD were unchanged in both groups and no injuries were reported. CON-
CLUSIONS: A 4-week concentrated period of daily SSG & HIT is effective for improving
endurance performance in youth soccer players. This was without injuries and without negat-
ing performance in power and change of direction.
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Key words: Intensified, small sided games, high intensity training, junior
Introduction
Periodization is described as a framework for systematic variation of training parameters with
the goal of optimizing adaptations to a particular sport 1. The general notion is that a cumula-
tive overload of training will result in a more powerful stimulus for adaptation, given that ap-
propriate recovery periods are planned. In terms of physical training for soccer players, a typ-
ical week may be devoted to strength/power, endurance, speed, agility, injury prevention and
specific motor skills training. Arguably this may be considered an established approach that
is common in most soccer clubs 2. It has rarely been examined whether this approach is the
most optimal way for enhancing physical capacities, particularly in youth soccer players. In-
deed, whereby practitioners typically manipulate the exercise selection, intensity and volume,
changes to the training organization are often overlooked.
Players are regularly tasked with performing at high levels and during regular time periods,
as shown during congested fixture periods 3. When designing training drills therefore, it is
highly likely that coaches will gravitate towards modes of training that can simultaneously
benefit a range of fitness components. Small-sided games (SSG), for instance, are looked up-
on favourably as a way of simultaneously improving the physical, technical and tactical qual-
ities of the players 4. In a similar instance, Taylor et al. 5 found repeated sprint training might
induce small to large improvements in power, speed, repeated sprint ability and endurance.
The notion is that of hastening the training response and/or getting ‘the biggest bang for their
buck’.
Concentrated or intensified training, sometimes analogous with broadly used terms such as
block periodization or shock mesocycle, has been postulated as a viable method of enhancing
performance 6. This form of training organization is generally considered more suitable for
continuous cyclical sports (running, swimming, cycling) 7,8 rather than intermittent team (e.g.
soccer) based sports. Favourable gains in physiological and performance measures have in-
deed been reported when including a period of intensified training in other sports (e.g. skiing
and cycling). For instance, increases in VO2max have been observed in response to period of
intensified training in cyclists 7,8 and skiers, respectively 9.
Concentrated/intensified training organization has gained fewer acceptances within soccer,
although there are emerging studies examining this area 6,10,11. The rationale for it not being a
common procedure is that it may inappropriately load the players and may actually prove de-
bilitative to performance, yet this tenet appears anecdotal given the paucity of underpinning
literature. In fact, a 2-week period of intensified training (SSG and speed endurance) im-
proved repeated sprint ability (RSA) and running economy in a group of senior soccer play-
ers 10. No improvement, however, was observed in Yo Yo Intermittent Recovery Test Level 2
(YYIRTL2) 10. Another study in semi-professional soccer players has shown a 2-week period
of sprint interval training (6 sessions) to improve YYIRTL1 and VO2max by 17 and 3%, re-
spectively 12. A recent study also showed superior RSA performance after a 13-day intensi-
fied period of high-intensity training (HIT) as well as a significant improvement in YYIRTL2
11. The training comprised of interval running, SSG or a dribbling course, each consisting of
4 x 4-min bouts separated by 3min active recovery 11. Although a reduction in performance
(YYIRTL2 and RSA mean and RSA index) was observed following a 25-day period without
3
HIT (in order to test sustainability), values remained significantly higher than baseline 11. Un-
fortunately, this particular study did not include a comparative group, nor were any monitor-
ing methods used to quantify the workload (e.g. heart rate). A more recent study of similar
duration (12 days) examined the effect of a maximal shuttle run shock microcycle in hypoxia
on soccer specific performance and oxidative stress in soccer players 6. Participants were
randomly assigned to hypoxia (~3300m) or normoxia training and performed 8 maximal
shuttle run sessions within 12 days. Interestingly, YYIRT performance improved inde-
pendently of the hypoxia stimulus.
It is unknown whether a concentrated period of SSG & HIT is an effective training approach
in youth soccer players. Therefore, the aim of the present study was to investigate the effects
of a 4-week period of concentrated SSG and HIT (5 d/wk) compared to regular soccer train-
ing incorporating 1 d/wk of SSG and HIT on performance measures in youth soccer players.
Our hypothesis is that a concentrated 4-week period of SSG & HIT will improve soccer-
specific fitness more than regular soccer training.
Methods
Experimental Approach to the Problem
All participants have given their informed consent for participation in the research study. The
study has been approved by Anti Doping Lab Qatar Institutional Review Board (protocol
number: SCH-ADL-070, date of approval: 21/10/2014).
Two separate teams competing in the same professional division in Qatar national league
were approached to participate. Based on previous 3 championship rankings both teams were
classified within the top 5 in the league. The training programme of both teams included 30
min physical training followed by 60 min of technical and tactical training whereby the coach
performed drills, positional play and some small and large sided games. Performance
measures were assessed using the 30-15 intermittent field test 13, 40 m sprint, countermove-
ment jump and a modified L run change of direction test. A cluster randomisation of partici-
pants was performed to determine the selection of groups.
Subjects
Nineteen male soccer players from 2 separate teams participated in the study (team 1; mean ±
SD age: 16.2 ± 0.8 years, height: 170.8 ± 7.7 cm, body mass: 58.2 ± 7.6 kg - team 2; age:
16.4 ± 0.7 years, height: 171.2 ± 7.5 cm, body mass: 57.9 ± 7.2 kg). Their normal week
schedule consisted of five training sessions (~90 min each), comprising of 30 min physical
training and 60 min of tactical training and one 90 min competitive league match. Players
reported no significant involvement in other sports outside of their training schedule. Both
teams consisted of ~20 players and all were measured at baseline.
Procedures
Prior to the intervention and as part of the 30 min physical training, both teams performed a
combination of endurance, strength/power, speed and agility over the 5 training days. For the
intervention period one team was assigned to a 4-week period of concentrated training
whereby their designated physical training time was replaced with 4 sessions of small sided
games (SSG) and 1 high intensity training (HIT) session (5 sessions in total) per week (SSG
& HIT, n = 12). The other team continued their regular (REG, n = 7) training organisation
4
which comprised of 1 (total) SSG and HIT session as well as training of strength/power and
speed and agility, respectively. All testing and the training intervention took place within the
competitive season, between October and November and approximately 2 months after the
start of preseason.
All participants were familiar with each of the testing procedures and the training content.
The technical coach was asked to refrain from strenuous drills and players to avoid demand-
ing physical activity in the 36 h preceding testing. All pre testing was performed 5 days be-
fore the start of the intervention and post testing within 7 days after the intervention period.
Maximal aerobic velocity, countermovement jump and change of direction were performed
pre and post the 4-week training intervention period. Technical and tactical training remained
similar between groups and comprised of technical drills and match play. Heart rate (Polar
team 2, EO, Finland), and session rate of perceived exertion (RPE) were recorded.
Training
All training sessions (SSG & HIT and REG) included a similar standardized warm-up (~10
min) consisting of running, jogging, dynamic exercises and short accelerations and decelera-
tions. The SSG & HIT performed 4 SSG and 1 interval training session per week (in total 16
SSG and 4 HIT sessions, Table 1). The SSG comprised of 4 x 4 min interspersed with a 1
min passive recovery. Player configuration was 4 vs 4 while task constraints were adapted for
each session to offer variety. All of the SSG’s were performed in an area of 30 x 25 m (rela-
tive pitch area= 93.7 m2) and a large number of balls were placed around the perimeter of the
area to ensure the intensity remained high. Verbal motivation was given during all sessions to
encourage the maintenance of a high work-rate. The HIT session was based on individual 30-
15 Intermittent Field Test (30-15 IFT) performance results. Players performed 2 x 6 min
(30/15 sec) at 110% of 30-15 IFT test performance and 2 x 4 min (15/15 sec) at 120% of 30-
15 IFT test performance. The two sets were separated by a rest period of 90 sec. The players
performed 8 repetitions in each set. The SSG & HIT group performed no other form of spe-
cific designated fitness or conditioning, such as strength, power speed and agility training.
The REG group training included only 1 combined SSG & HIT session per week that con-
sisted of 4 x 4 min SSG interspersed with 1 min passive recovery and 2 x 6 min (30/15 sec) at
110% 30-15 IFT test performance (8 repetitions in total). The constraint for the SSG training
in the REG group was that no goal was included and teams had to retain possession. The
REG group also performed two strength and power sessions including resistance machine
training, plyometrics and field based strength training; 1 speed and agility (accelerations, de-
celerations and 1 vs 1 duals) and 1 injury prevention (FIFA 11+) session per week. In total
the REG group performed 4 SSG & HIT sessions during the 4-week period (Table 1).
Training intensity was classified into 5 different zones: (1) 90100 %; (2) 8089 %; (3) 70
79 %; (4) 6069 %; and (5) 5059 % of maximal heart rate (HR). The warm up was excluded
from the analysis with only active training time analysed. Rate of perceived exertion was rec-
orded within 10 min of exercise completion using the CR-10 Borg scale, as described by Fos-
ter et al 14. The duration (min) of the entire training session was also noted and the product of
the session-RPE multiplied by session duration (min) was termed the session load. All play-
ers had been familiarized to this scale for at least one season before the start of the study.
INSERT TABLE 1 ABOUT HERE
5
Testing
The 30-15 IFT was performed outside on a grass field and players wore regular soccer boots.
The 30-15 IFT protocol consists of 30 sec shuttle runs in a forward direction between two
lines 40 m apart interspersed with 15 sec passive recovery periods 13. Running speed began at
8 km/h with increments of 0.5 km/h every 30 sec. During the 30-sec running periods, partici-
pants were instructed to run back and forth at the given pace, governed by a pre-recorded
beep and until volitional exhaustion, defined as being unable to follow the pace for 2 consec-
utive beeps. During the 15-sec recovery periods, the players were required to walk in a for-
ward direction towards the nearest line, either the two lines 40 m apart or the mid-line; next
30-sec running bout started from this line. The velocity attained during the final complete
stage was determined as the participant’s maximal aerobic velocity 13. Test reliability on a
sub sample (n = 16) was r = 0.91.
Countermovement jump (CMJ) height was assessed from time in flight using an Optojump
photocell system (Microgate, Bozen, Italy). All participants performed a standardised 10 min
warm up consisting of jogging, skipping, dynamic exercises and accelerations and 2 practice
jumps prior to test trial. Participants completed 3 countermovement vertical jumps with hands
on the hips with 30 sec of rest and the best attempt was taken for further analysis. Test relia-
bility on a sub sample (n = 16) was r = 0.89.
Change of direction (COD) performance was assessed using a modified L run COD test. Par-
ticipants placed the preferred foot 0.50 m behind the starting set of timing gates (Microgate,
Bozen, Italy). Upon instruction, they performed a maximal sprint towards a pole at 10 m be-
fore decelerating and perform a 90-degree cutting manoeuvre before sprinting through the
second set of timing gates 10 m away. The test was 20 m in length and players performed 2
trials to the left and right (4 in total) with the best performance for each side taken for analy-
sis. Test reliability on a sub sample (n = 16) was of r = 0.91.
Statistical Analysis
Descriptive statistics of the data are presented as means ± standard deviation (SD). Statistical
analysis was performed using repeated measure ANOVA (condition x time) and magnitude-
based inferences (MBI). MBI is a well-established analytic approach that provides infor-
mation on the magnitude of effects of training that is meaningful to the practitioners. Mean
effect size (ES) were calculated and the criteria to interpret the magnitude of the ES were:
0.00.2 trivial, 0.20.6 small, 0.61.2 moderate, 1.22.0 large, and >2.0 very large 15. Differ-
ences between groups with regards to average training heart rate and player load were as-
sessed with t-test for independent samples. Statistical analysis was performed using the Sta-
tistical Package for the Social Sciences (SPSS, version 21.0.) and the level of significance
was set at p< 0.05.
Results
A greater 30-15 IFT final running speed from pre to post (8.2 % improvement, p< 0.05) and a
small (ES= 0.57) beneficial effect for the SSG & HIT group was found (Table 2). A small
beneficial within group effect (COD right, ES= 0.32; COD left, ES= 0.24), though not signif-
icant decrease (improvement), was found for COD performance on the right and left side for
6
the SSG & HIT. A trivial change was reported in countermovement jump performance for the
SSG & HIT. The within group change was trivial for all measures (range: ES=0.03-0.20)
(Table 2) for the REG group.
INSERT TABLE 2 ABOUT HERE
No difference was observed between the groups for training time (90 min). Figure 1 illus-
trates the distribution of the endurance training into the different intensity zones for both
groups. Average training intensity (% HR max) and player load were greater (p< 0.05) for the
SSG & HIT (83.7 % and 344 AU) vs REG group (73.4 % and 253 AU), respectively. Attend-
ance was 89 % and 87 % for the SSG & HIT and REG group during the training intervention,
respectively. No injuries, in accordance with Fuller et al. 16 classification, were reported for
either group during the 4-week training intervention.
INSERT FIGURE 1 ABOUT HERE
Discussion
The aim of the present study was to compare the effect of a 4-week period of concentrated
SSG & HIT (4 d/wk) vs a regular training approach (SSG & HIT 1 d/wk) on fitness charac-
teristics in youth soccer players. The 4-week period of intensified training including SSG &
HIT training improved endurance performance by 8.2 % in these soccer players. Although no
improvement was seen in countermovement jump or change of direction following the SSG
and HIT neither was there any negative effect. Accordingly, it seems solely performing SSG
and HIT can provide a potent stimulus capable of inducing gains in exercise performance.
The interest towards periods of concentrated training has increased steadily over recent years.
However, it remains less studied in soccer compared to other sports such as skiing and cy-
cling 7,8,9 . The comparison of our research with similar studies, therefore, is limited 6,10,11. We
observed 4 weeks of concentrated SSG & HIT training performed 5 days per week to be su-
perior to 1 day per week. Research has shown even 14 days 6,11 of intense training to provide
a beneficial effect on performance measures in soccer players. Collectively, these studies,
including the present one, demonstrate concentrated training as a viable approach to training
of soccer players of different levels. The improvement in endurance performance reported in
the present study is in agreement with one study 11 but not wholly with another 10. Although
Christensen and colleagues 10 reported no significant improvement in YYIRTL2, significant
differences were shown from pre to post in running economy and RSA.
It is also noteworthy that no other form of specific training relating to strength, power, injury
prevention, speed and/or agility was undertaken in the present study in the SSG and HIT
group. This culminated in 20 endurance sessions over the 4-week period, compared to 4 ses-
sions for the regular group, respectively. Obviously the concern with focusing solely on one
fitness component is that of a concomitant decrease in other physical qualities. We have
shown over a relatively short term this was not the case. According to our results the concen-
trated training approach was not associated with negative effects in CMJ and/or COD. We
speculate that the high frequency of SSGs performed during the course of the 4-week period
as being a possible explanatory factor. Indeed, the positive effect of SSG on agility perfor-
mance has recently been shown in soccer players 17. Even at the elite level, whereby gains in
7
performance become more challenging, adding SSG to a training programme has proven to
be beneficial 4. Dedicated time towards improving these qualities (power, COD and speed) is
indeed important for the overall development of youth players 18. During certain stages, how-
ever, coaches should not be deterred from including a relatively short period of organised
training focusing predominantly on SSG and/or HIT. Admittedly, the medium and long-term
implications of SSG/HIT on speed, COD and power is unknown and future research should
address the sustainability or whether any negative effects are associated with this training ap-
proach. It is worth remembering, however, that Wahl et al. 11 reported fitness levels to re-
main significantly higher than baseline despite a 25-day period without HIT. According to
our results it seems that a period of concentrated training comprising of SSG & HIT is a fea-
sible option of training in youth soccer players. Its appeal is substantiated by no reported in-
juries during the intervention period. The process of intensifying training is commonly em-
ployed by athletes in an attempt to enhance performance 19. Obviously, caution must be taken
to avoid non-functional overreaching and subsequent overtraining syndrome. A degree of
functional overreaching may, however, be key to performance enhancement 20.
Players are regularly tasked with performing at high levels and during regular time periods,
as shown during congested fixture periods 3. Integrating a period of concentrated training
may facilitate this transition and possibly identify players who may excel, or struggle, in
these circumstances. Indeed, the coach also perceived a greater sense of ‘effort and resili-
ence’ amongst the players. We concede these observations lack any objective data, however,
it would be somewhat erroneous of us to dismiss such real-world feedback when examining
the feasibility and appropriateness of this concentrated period of training.
The findings of the present study raise interest in ways to further improve physical perfor-
mance in youth soccer players. This resulted in greater improvements in endurance perfor-
mance. Although commonplace, it has rarely been examined whether it (regular approach) is
optimal for enhancing physical capacities. Practitioners should be willing to adopt different
training approaches, particularly at the youth level where the focus should be more on devel-
opment rather than performance. Training modifications typically manipulate the exercise
selection, intensity and volume in an attempt to elicit greater gains in performance, changes
to the training organisation are however, often overlooked.
We acknowledge the current study has limitations. Recruiting participants from two separate
teams is particularly acknowledged, however, this is a common issue within applied research.
Although similarities were evident, it is inevitable that differences in exact technical and tac-
tical content may be a contributing factor. In addition, pre-testing values of 30-15 intermittent
fitness test might have affected at some extent the outcome of training. It is likely that future
studies will benefit from additional objective measures, such as global positioning systems, to
offer a greater insight regarding the workloads performed 21,22. Longitudinal experiments are
necessary to identify the long-term effect as well as uncover any potential confounding effect
associated with this training approach.
In conclusion, 4 weeks of daily (5 d/wk) SSG & HIT is superior to regular soccer training
incorporating 1 d/wk of SSG & HIT to improve intermittent endurance performance without
negatively impacting COD and leg power. Although no improvement was observed for leg
power and COD performance, neither was there any decrement in these parameters. In addi-
tion, no injuries were reported as a result of this training. Thus, a concentrated period of train-
8
ing, whereby focus is given to one fitness component, is effective in improving endurance
without negating other physical fitness qualities.
Practical applications
Small-sided games and high intensity running drills constitute an important part of a weekly
training programme within a soccer club setting. The tendency is for coaches to focus on ma-
nipulating the constraints (rules, instructions, etc) of these (SSG and HIT) elements. Our re-
sults may provide reassurances to coaches that changing the training organisation (i.e. includ-
ing a period of concentrated training) is an effective tool that is worth considering. Imple-
menting this approach (intensified period of training) may be particularly useful when the
preparation period is short (i.e. during preseason) or when the players need to develop and/or
maintain several physical qualities while upholding a large element of technical and tactical
involvement. Players and coaches will be highly motivated and receptive towards our find-
ings knowing that predominantly playing soccer, in a SSG format, can prove beneficial to
general physical fitness. Including an intensified period of training may also provide an, albe-
it indirect, insight into how players cope with greater training load and intensity. This may
prove useful given that the demands of soccer training and match play seem to be ever grow-
ing.
Acknowledgements
The authors would wish to thank the athletes and coaching staff for participating in the study.
We wish to confirm that there are no known conflicts of interest associated with this publica-
tion and there has been no significant financial support for this work that could have influ-
enced its outcome.
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Table 1. Weekly training schedule and approximate training session durations for the SSG &
HIT and REG group.
Sunday
Tuesday
Wednesday
Thursday
Friday
Saturday
SSG &
HIT
group
SSG
(transition
play)
HIT
SSG
SSG (in-
cluding
goal
keepers)
Match
No train-
ing
REG
group
Strength
& power
training
Strength
& power
training
Injury pre-
vention
Speed
and Agili-
ty
Match
No train-
ing
Table 2. Performance measures before and after 4 weeks of intensified SSG&HIT vs
regular training (mean (SD)).
SSG&HIT
REG
Test
Pre
Post
ES
Pre
Post
ES
30-15 IFT (km/h)
17.0(1.1)
18.4(0.8)*
0.57
17.9(1.3)
18.2(1.6)
0.10
Countermovement
Jump (cm)
33.5(5.8)
34.0(5.1)
0.04
30.8(3.8)
31.7(5.1)
0.20
Agility Right (s)
4.21(0.1)
4.08(0.2)
0.32
3.89(0.1)
3.88(0.1)
0.03
Agility Left (s)
4.23(0.2)
4.16(0.1)
0.24
3.91(0.1)
3.88(0.1)
0.11
SSG&HIT=Small sided games and high intensity training; REG= Regular training;
IFT=Intermittent field test; ES=Effect size; *p< 0.05 vs pre value
11
Fig 1. Heart rate distribution expressed in percentage of active training time in selected heart
rate zones. Average heart rate was greater (p<0.05) for the SSG&HIT (mean (SD)).
... Concerning VIFT, a previous study reported a 4.1% change in performance after an SSG training period in basketball [28]. An even higher percentage of change in VIFT in another study (8.2%), in which the protocol combined SSGs and HIIT [29]. Both results contradict the current findings as no difference was detected from the pre to post-test. ...
... Therefore, the number of high-speed actions observed in the current study might be lower than in the previous one, which explains the differences in the results. Besides, the other research that revealed positive adaptations in IFT performance [29] complemented the SSG training with the HIIT sessions. Therefore, HIIT activities might 14:199 have played a significant role in providing players with high-speed training stimuli, which explains the results obtained. ...
... A study with handball players found similar positive adaptations after a training program composed of 3-a-side SSGs [35]. Interestingly, other studies that adopted 4-a-side SSGs during the training period reported no improvements in CMJ [29,36], similar to the current results in the 5-a-side protocol (medium-sided game). Therefore, it might be argued that smaller formats potentially impact CMJ more prominently than larger ones. ...
Article
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Aim This study tested the effects of two training programs (one program based on extreme sided-games of 1v1 vs. one program based on the medium-sided game of 5v5) on the physical fitness adaptations of youth soccer players. In specific, it was analyzed the effects of the training programs on the 5–0–5 change-of-direction time (5–0–5 time), countermovement jump (CMJ), and final velocity in the 30–15 Intermittent Fitness test (VIFT). Methods This study followed a randomized parallel study design. Twenty male regional-level soccer players (age: 17.0 ± 0.3 years old) were randomly assigned to two groups: (1) the 1v1 format; and (2) the 5v5 format. The training intervention lasted four weeks. The week before (baseline) and the week after the intervention, the participants were assessed in the 5–0–5 change-of-direction test (measured using timing gates), CMJ (measured by photoelectric cells), and 30–15 Intermittent Fitness test. The training intervention consisted of 8 sessions (2 sessions per week). The 1v1 group performed four repetitions of 30 s in each session, while the 5v5 group performed four repetitions of 4 min. Results The 5–0–5 time changed − 4.82% ( p = 0.004; d = 1.115) for the 1v1 group and − 4.26% ( p = 0.004; d = 0.859) for the 5v5 group. CMJ changes occurred both in the 1v1 and 5v5 group and amounted to 1.7% ( p = 0.003; d = 0.509) and 1.2% ( p = 0.263; d = 0.155) respectively. VIFT changed 2.6% ( p = 0.718; d = 0.178) for the 1v1 group and 3.0% ( p = 0.593; d = 0.274) for the 5v5 group. The 1v1 group reported significantly lower post-intervention 5–0–5 time than the 5v5 group (− 4.3%; p = 0.048; d = 0.954), although no significant differences in CMJ (3.2%; p = 0.147; d = 0.678) and VIFT (2.5%; p = 0.697; d = 0.177) were revealed. Conclusions The extreme-sided games meaningfully beneficiated the vertical jump height and change-of-direction performance of youth soccer players. The extreme-sided games seem more beneficial than medium-sided games for improving these physical abilities while showing that four weeks were enough to impact the players significantly.
... A recent review indicates the sustainability and effectiveness of high intensity interval training shock microcycle in different athletes to improve intermittent and continuous running performance [8]. Similar benefits also reported on soccer [11,13]. Interestingly, Joo (2018) [14] reported that the restoration of performance (YYIR2 and RSA) after a period of detraining requires an equal period of high intensity aerobic workouts Therefore, the limited preparation time that federations had provided, led the coaches to use the HIIT-Shock microcycle structure that according to the literature could have positive effects on players' physical condition in a short time. ...
... However, studies investigating the effect of a SM on soccer players are limited [4,11,13] while none have been performed on high-level soccer players. Therefore, the aim of our study was to apply a shock-microcycle (SM) after the lockdown period and return to training and assess its effect on elite professional soccer players' performance. ...
... In this study, we used YYIR2, an intermittent test to assess the aerobic capacity of players and we observed a significant improvement. Our findings are in line with those of previous research which found that the HIIT application improves performance in intermittent tests until exhaustion (YYIR2, 30-15 intermittent fitness test) [11,13]. More specifically, the players during the 2nd measurement covered 10.8% more distance compared to the 1st measurement. ...
Article
Objectives: Decreases in physical fitness are inevitable after two to six week period of detraining in athletes. Lockdown period changed the characteristics of soccer players’ training. Aim of the study: The aim of our study was to apply a HIIT shock-microcycle (SM) after return to training and assess its effect on players’ performance. Equipment and methods: Nineteen elite professional soccer players during the lockdown period (LP) from March to May 2020 (8 weeks) performed 3-4 individual training sessions per week. The training sessions included running boots of anaerobic short and aerobic prolonged duration intervals. Intensity was determined according to lab ergospirometry test 2 weeks before LP. All the players followed an indoor program, 3-6 sessions per week consisted of core, balance and flexibility exercises (∼45 minutes). SM training content was same for both groups and took place the first two weeks after LP, consisted by eight high intensity interval training sessions (HIIT), two technique, two tactical sessions and two days off. Results: Repeated sprint ability mean time (RSAMeanTime) and Repeated sprint ability performance – sprint no 4,5,6 (RSA4,5,6S) improved after SM (p=0.025, Effect size:r²=0.331, p=0.010, Effect size:r²=0.411, p=0.009, Effect size:r²=0.418, p=0.037, Effect size:r²=0.293, respectively. Yo-Yo intermitted recovery test level 2 (YYIR2TotalDistance) that covered by players during the 2nd measurement was 10.8% longer (p=0.004, Effect size:r²=0.483). Also, the YYIR2HeartRateRecovery percentage was lower during the 2nd measurement (p=0.014, Effect size:r²=0.107). Conclusions: These results indicate that SM can improve YYIR2 and RSA performance thus it is a useful tool to regain physical attributes in a short period.
... Six studies found a significant improvement in CMJ performance from the start of pre-season to the end of the in-season phase. 22,29,31,33,38,42,44 This improvement was also observed from the start to end of the pre-season phase. 29,42 Conversely, no significant change in CMJ performance was observed across a training microcycle, 26,45 mesocycle (4-9 weeks) 19,36 and full season. ...
... The assessment of changes in sprint and agility capabilities was assessed in eight studies 19,22,33,[36][37][38]42,46 (Table 6). Three studies found significant improvements in 5 m, 36 15m 46 and 30m 38 sprint performance across the pre-season phase. ...
... Fair Paul et al. 38 1 ...
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Objectives 1) To evaluate current physical performance tests used within professional male youth soccer; 2) to understand the relationship of these tests performance in relation to specific measures of external and internal training load (TL) to conclude if there is a subsequent change in test performance. Methods Relevant literature was searched using five electronic databases (PubMed Medline, SPORTDiscus, Web of Science, CINAHL and Scopus), with additional articles identified by the authors. Articles relating to TL and physical development assessment within professional male youth soccer players were evaluated. Results Database searches yielded 5683 articles following removal of duplicates. After screening the titles, abstracts and full texts, 28 articles were identified. Both external TL (total distance, high speed distance, duration) and internal TL (rating of perceived exertion, training impulse) measures were found to be associated with improvements in physical test performance across both pre-season and in-season phases. Field-based testing was found to be sensitive to changes in physical performance for aerobic capacity, lower body power/strength and sprint performance. However, limited sensitivity to change was found when assessing player agility performance. Conclusion Future research in this area should look to enhance our understanding of the dose-response of TL with changes in fitness across different age groups in professional male youth soccer.
... The SBT group showed greater improvements in vertical jump height (5.9% vs. 2.9%, mean difference = 2.3%, p < 0.05) and explosive power (8.4% vs 5.6%, mean difference = 2.8%, p < 0.05) compared to the SSG group, respectively. These results were confirmed by Rodriguez-Fernandez et al. [32] and Paul et al. [33], who reported that five-week pre-season and four-week SSG-based conditioning training was not sufficient to improve amateur soccer players' vertical jump heights. These significant developmental differences for the vertical jump height and explosive power between the groups may be explained by the fact that the SBT group had more chances to perform jumping and short-term actions during its sessions than the SSG group did [34]. ...
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... The Football Association of Thailand controls the Thailand national football squad, RTGS, which competes in senior international football on behalf of Thailand. Thailand is Southeast Asia's most successful football team, having won five AFF Championship trophies and nine Southeast Asian Games gold medals at the senior level, more than any other Southeast Asian nation (Paul, Marques, & Nassis, 2019;Stull, Glick, & Kamis, 2021). Thailand placed third at the 1972 AFC Asian Cup, which it hosted, and has had seven overall appearances in the AFC Asian Cup. ...
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Globally, team performance has become a crucial factor for the success of any sport, attracting the interest of regulators, coaches, and new researchers. Therefore, the current study investigates the impact of critical factors such as physical fitness, training process, and team support on the performance of the Thai national football team. In addition, this article examines the mediating effect of player satisfaction on the relationships between physical fitness, training process, team support, and football team performance in Thailand. The researchers collected the data using primary data collection methods such as questionnaires. The respondents were selected using purposive sampling, and smart-PLS was used to assess the reliability and relationships between variables. The results demonstrated that physical fitness, training process, and team support positively affect the performance of the Thai national football team. In addition, the results indicated that player satisfaction significantly mediates the relationships between physical fitness, training process, team support, and football team performance in Thailand. This article assists regulators in developing regulations regarding team performance and serves as a guide for future researchers investigating this field.
... According to Karahan [18], SSG training was relevant and can be used to improved power performance due to the reduction of players in the SSG game formation causes players have to do acceleration more often, on a regular basis indirectly builds up explosive of leg strength. In addition, result of 8 week SSG training in this study sufficient to improve power performance, in contrast to the study by Rodríguez-Fernández et al. [20], and Paul et al. [21] which showed that SSG training for 4 and 5 weeks was not sufficient to improve power performance. It proved that power development can be influenced by duration of intervention training. ...
Article
Background and Study Aim. Despite many evidences showed the effectiveness of small sided games (SSG) to be included in sport training programs, majority of the study was done in soccer, while is very limited in hockey. The purpose of this study was to determine and compare the effects of small sided games and traditional training on physical fitness components (cardiovascular endurance, power, speed) and skills (dribbling, hitting, passing) among Under-12 hockey players. Material and Methods. A total of 36 primary schools’ male students aged below 12 that represent their district were randomly divided into three groups; i) 3x3, ii) 4x4 and iii) traditional training (TT). The yo-yo test (cardiovascular endurance), standing long jump test (power) and 30m sprint test (speed) were conducted to measure level of physical fitness performance while the skills of the players was tested based on the skills of dribbling, hitting and passing. Pre- and post-tests were conducted on all fitness and skill level before and after 8 week intervention period. Mixed between within analysis of variances (ANOVA) was used to analyze the differences in physical fitness and skills performance between and within the three groups. Results. The results of this study showed all groups managed to improve their physical fitness and skills in the post test. However, the 3x3 and 4x4 SSG have better improvement compared to TT in physical fitness while no significant differences were found in skills tests. Conclusions. In conclusion, SSG interventions were found to be more effective in improving physical fitness but not in terms of skills. Coaches are encouraging to implement SSG in their training program in order to improve both physical and skills among hockey players.
... The HR PEAK% and HR MEAN% values found in both SSGs investigated in this study are similar to those reported in previous studies on the three vs. three SSG format performed by soccer players of a similar age (Sub-17) [40][41][42]. Furthermore, studies on SSG training (training periods above four weeks) indicate the necessity for HR mean values to be above 80% of HR max to improve aerobic performance [43][44][45][46]. Therefore, the results of the present study reinforce the potential use of different SSGs for the improvement of aerobic performance in soccer athletes, including the offside rule. ...
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This study aimed to compare the physiological demand between three vs. three small-sided games (SSGs) with (3vs.3WITH) and without (3vs.3WITHOUT) the offside rule, as well as the within and between-session reliability of this demand. Twenty-four U-17 soccer athletes performed various three vs. three (plus goalkeepers) SSGs with and without the offside rule. The data collection was performed within an eight-week period. Athletes’ heart rate was monitored during the SSG. The variables analyzed were the percentage mean heart rate (HRMEAN%) and the percentage peak heart rate (HRPEAK%). For the analysis of within-session reliability, the mean value of the first two and last two SSG bouts performed within one day were used. The between-session reliability was calculated using the mean value of the four SSG bouts of each SSG type performed on two different days. In both SSGs, the values for reliability were significant and were classified as moderate to excellent. There were no significant differences in the physiological demand among SSG types. We concluded that the offside rule does not influence the physiological demand in a three vs. three SSG and the HRMEAN% and HRPEAK% present moderate to excellent reliability in a three vs. three SSG with and without the offside rule.
... 10 Notwithstanding, studies demonstrate that periods with intensified training for a few weeks enhance performance without imposing a greater risk of overreaching. 11,12 When performing intensified training, the intensity is increased above normal, usually by increasing the volume of high-intensity interval training, while decreasing the volume of low-intensity to moderate-intensity training and resistance training. In practice, this can be done by introducing speed endurance training (SET), which is characterized by short intervals (10-60 s) performed at maximal or near-maximal intensities interspersed by recovery >6 times the exercise duration. ...
Article
Purpose: We investigated whether 4 weeks of intensified training consisting of speed endurance training (SET) enhanced high-intensity exercise performance in youth national-team ice hockey players. Methods: Utilizing a randomized crossover design, we subjected 17 players to 4 weeks of SET, comprising 6 to 10 × 20 seconds at maximal effort (>95% maximum ice skating speed) with 120-second recovery performed 3 times weekly, or maintenance of regular training (control period). Before and after each period, players completed ice-hockey-specific tests on ice, including a Yo-Yo Intermittent Recovery Level 1 test, a 30-m sprint test, and an agility test. On a separate day, players were assessed for body composition with dual-energy X-ray absorptiometry and performed countermovement jump, maximal voluntary isometric knee extensor contraction, a 15-second maximal sprint test, and a submaximal and incremental test on a bike ergometer in which pulmonary oxygen consumption was determined. Results: Yo-Yo Intermittent Recovery Level 1 test performance increased (P < .001) by 14% (95% CI, 201-496 m) during the SET period. Maximal pulmonary oxygen consumption (P < .05) and time to exhaustion (P < .05) were 4.8% and 6.5% higher, respectively, after the SET period than before. Fat-free mass increased (P < .01) during the SET period by 1.7 kg (95% CI, 1.0-2.5), whereas fat mass remained unchanged. These effects were superior to the control period. Conclusions: These findings underpin the effectiveness of SET for improving on-ice high-intensity performance and highlight that elite ice hockey players can benefit from implementing SET.
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In general, the concept of a mechanism in biology has three distinct meanings. It may refer to a philosophical thesis about the nature of life and biology, to the internal workings of a machine-like structure, or to the causal explanation of a particular phenomenon [1]. Understanding the biological mechanisms that justify acute and chronic physiological responses to exercise interventions determines the development of training principles and training methods. A strong understanding of the effects of exercise in humans may help researchers to identify what causes specific biological changes and to properly identify the most adequate processes for implementing a training stimulus [1]. Despite the significant body of knowledge regarding the physiological and physical effects of different training methods (based on load dimensions), some biological causes of those changes are still unknown. Additionally, few studies have focused on natural biological variability in humans and how specific human properties may underlie different responses to the same training intervention. Thus, more original research is needed to provide plausible biological mechanisms that may explain the physiological and physical effects of exercise and training in humans. In this Special Issue, we discuss/demonstrate the biological mechanisms that underlie the beneficial effects of physical fitness and sports performance, as well as their importance and their role in/influences on physical health. A total of 28 manuscripts are published here, of which 25 are original articles, two are reviews, and one is a systematic review. Two papers are on neuromuscular training programs (NMTs), training monotony (TM), and training strain (TS) in soccer players [2,3]; five articles provide innovative findings about testosterone and cortisol [4,5], gastrointestinal hormones [6], spirulina [7], and concentrations of erythroferrone (ERFE) [8]; another five papers analyze fitness and its association with other variables [7,9–12]; three papers examine body composition in elite female soccer players [2], adolescents [6], and obese women [7]; five articles examines the effects of high-intensity interval training (HIIT) [7,10,13–15]; one paper examines the acute effects of different levels of hypoxia on maximal strength, muscular endurance, and cognitive function [16]; another article evaluates the efficiency of using vibrating exercise equipment (VEE) compared with using sham-VEE in women with CLBP (chronic lowback pain) [17]; one article compares the effects of different exercise modes on autonomic modulation in patients with T2D (type 2 diabetes mellitus) [14]; and another paper analyzes the changes in ABB (acid–base balance) in the capillaries of kickboxers [18]. Other studies evaluate: the effects of resistance training on oxidative stress and muscle damage in spinal cord-injured rats [19]; the effects of muscle training on core muscle performance in rhythmic gymnasts [20]; the physiological profiles of road cyclist in different age categories [21]; changes in body composition during the COVID-19 [22]; a mathematical model capable of predicting 2000 m rowing performance using a maximum-effort 100 m indoor rowing ergometer [23]; the effects of ibuprofen on performance and oxidative stress [24]; the associations of vitamin D levels with various motor performance tests [12]; the level of knowledge on FM (Fibromyalgia) [25]; and the ability of a specific BIVA (bioelectrical impedance vector analysis) to identify changes in fat mass after a 16-week lifestyle program in former athletes [26]. Finally, one review evaluates evidence from published systematic reviews and meta-analyses about the efficacy of exercise on depressive symptoms in cancer patients [27]; another review presents the current state of knowledge on satellite cell dependent skeletal muscle regeneration [28]; and a systematic review evaluates the effects of exercise on depressive symptoms among women during the postpartum period [29]
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In summary, our study showed that a RPE-based workload calculation is not without limitations and this should be taken into account from scientists and practitioners. Indeed, this point has been raised by others as well (3, 4). Studies showing low-to-moderate correlation coefficients between RPE and GPS-derived workload data are on the same line (6). As mentioned by the letter’s author previously, “despite various contributing factors, session rating of perceived exertion has the potential to affect a large proportion of the global sporting and clinical communities” (7). We believe our study has indeed highlighted some of these “contributing factors”. As we acknowledge in our manuscript, “the sRPE is a practical low-cost tool to assess training load in soccer”. However, this does not justify that it can be an accurate and sensitive method in all cases, and all its limitations should be considered. Either subjective or objective data should be combined, or one should move towards assessing the training physiological outcome and eliminate the use of subjective tools, especially with elite players (8, 9). There is a risk of spreading inappropriate information by presenting RPE-based method as the gold standard for workload quantification. We strongly suggest a more open-minded and critical thinking approach to the related data presented in the literature. This approach might help advance the knowledge in the field which at the moment is superficial and of limited extent.
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I Want to Monitor My Athlete But Where Do I Start? Given the relationships among athlete workloads, injury1 and performance,2 athlete monitoring has become critical in the high performance sporting environment. Sports medicine and science staff have a suite of monitoring tools available to track how much ‘work’ an athlete has performed, the response to that ‘work’, and whether the athlete is in a relative state of fitness or fatigue. The volume of literature, coupled with clever marketing around the ‘best approaches’ to optimizing athlete performance, has resulted in practitioners having more choices than ever before. Furthermore, the range of different practices used in sport, and the lack of agreement between parties emphasizes the importance of having a clear rationale for athlete monitoring. The aim of this paper is to provide a practical guide to strategic planning, analyzing, interpreting, and applying athlete monitoring data in the sporting environment irrespective of data management software.
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Background Agility is an important characteristic of team sports athletes. There is a growing interest in the factors that influence agility performance as well as appropriate testing protocols and training strategies to assess and improve this quality. Objective The objective of this systematic review was to (1) evaluate the reliability and validity of agility tests in team sports, (2) detail factors that may influence agility performance, and (3) identify the effects of different interventions on agility performance. Methods The review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We conducted a search of PubMed, Google Scholar, Science Direct, and SPORTDiscus databases. We assessed the methodological quality of intervention studies using a customized checklist of assessment criteria. Results Intraclass correlation coefficient values were 0.80–0.91, 0.10–0.81, and 0.81–0.99 for test time using light, video, and human stimuli. A low-level reliability was reported for youth athletes using the video stimulus (0.10–0.30). Higher-level participants were shown to be, on average, 7.5 % faster than their lower level counterparts. Reaction time and accuracy, foot placement, and in-line lunge movement have been shown to be related to agility performance. The contribution of strength remains unclear. Efficacy of interventions on agility performance ranged from 1 % (vibration training) to 7.5 % (small-sided games training). Conclusions Agility tests generally offer good reliability, although this may be compromised in younger participants responding to various scenarios. A human and/or video stimulus seems the most appropriate method to discriminate between standard of playing ability. Decision-making and perceptual factors are often propositioned as discriminant factors; however, the underlying mechanisms are relatively unknown. Research has focused predominantly on the physical element of agility. Small-sided games and video training may offer effective methods of improving agility, although practical issues may hinder the latter.
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Repeated-sprint training appears to be an efficient and practical means for the simultaneous development of different components of fitness relevant to team sports. Our objective was to systematically review the literature and meta-analyse the effect of repeated-sprint training on a selection of field-based measures of athletic performance, i.e. counter-movement jump, 10 m sprint, 20 m sprint, 30 m sprint, repeated-sprint ability and high-intensity intermittent running performance. The SPORTDiscus, PubMed, MEDLINE and Web of Science databases were searched for original research articles. Search terms included 'repeated-sprint training', 'sprint training', 'aerobic endurance', 'repeated-sprint ability', 'counter-movement jump' and 'sprint performance'. Inclusion criteria included intervention consisting of a series of ≤10 s sprints with ≤60 s recovery; trained participants; intervention duration of 2-12 weeks; field-based fitness measures; running- or cycling-based intervention; published up to, and including, February 2014. Our final dataset included six trials for counter-movement jump (two controlled trials), eight trials for 10 m sprint, four trials for 20 m sprint (three controlled trials), two trials for 30 m sprint, eight trials for repeated-sprint ability and three trials for high-intensity intermittent running performance. Analyses were conducted using comprehensive meta-analysis software. Uncertainty in the meta-analysed effect of repeated-sprint training was expressed as 95 % confidence limits (CL), along with the probability that the true value of the effect was trivial, beneficial or harmful. Magnitude-based inferences were based on standardised thresholds for small, moderate and large changes of 0.2, 0.6 and 1.2 standard deviations, respectively. Repeated-sprint training had a likely small beneficial effect in non-controlled counter-movement jump trials (effect size 0.33; 95 % CL ±0.30), with a possibly moderate beneficial effect in controlled trials (0.63; 95 % CL ±0.44). There was a very likely small beneficial effect on 10 m sprint time in non-controlled trials (-0.42; 95 % CL ±0.24), with a possibly moderate beneficial effect on 20 m sprint time in non-controlled (-0.49; 95 % CL ±0.46) and controlled (-0.65; 95 % CL ±0.61) trials. Repeated-sprint training had a possibly large beneficial effect on 30 m sprint performance in non-controlled trials (-1.01; 95 % CL ±0.93), with possibly moderate beneficial effects on repeated-sprint ability (-0.62; 95 % CL ±0.25) and high-intensity intermittent running performance (-0.61; 95 % CL ±0.54). Repeated-sprint training can induce small to large improvements in power, speed, repeated-sprint ability and endurance, and may have relevance for training in team sports.
Article
Variations in definitions and methodologies have created differences in the results and conclusions obtained from studies of football (soccer) injuries, making interstudy comparisons difficult. Therefore an Injury Consensus Group was established under the auspices of Fédération Internationale de Football Association Medical Assessment and Research Centre. A nominal group consensus model approach was used. A working document on definitions, methodology, and implementation was discussed by the group. Iterative draft statements were prepared and circulated to members of the group for comment before the final consensus statement was produced. Definitions of injury, recurrent injury, severity, and training and match exposures in football together with criteria for classifying injuries in terms of location, type, diagnosis, and causation are proposed. Proforma for recording players’ baseline information, injuries, and training and match exposures are presented. Recommendations are made on how the incidence of match and training injuries should be reported and a checklist of issues and information that should be included in published reports of studies of football injuries is presented.
Article
To investigate the effect of a maximal shuttle-run shock microcyle in hypoxia on repeated sprint ability (RSA,6x40-m/20”), Yo-Yo-intermittent-recovery (YYIR) test performance and redox-status. Fourteen players (age:23.9±2.1yr), randomly assigned to hypoxia (~3300m) or normoxia training, performed 8 maximal shuttle-run training sessions within 12 days. YYIR-test performance and RSA fatigue-slope improved independently of the hypoxia stimulus (p<0.05). Training reduced the oxidative stress level (-7.9%, p<0.05), and the reduction was associated with performance improvements (r=0.761,ΔRSA; r=-0.575,ΔYYIR, p<0.05).
Article
Purpose: To examine the effect of low-volume sprint interval training (SIT) on the development (part 1) and subsequent maintenance (part 2) of aerobic fitness in soccer players. Methods: In part 1, 23 players from the same semiprofessional team participated in a 2-wk SIT intervention (SIT, n = 14, age 25 ± 4 y, weight 77 ± 8 kg; control, n = 9, age 27 ± 6 y, weight 72 ± 10 kg). The SIT group performed 6 training sessions of 4-6 maximal 30-s sprints, in replacement of regular aerobic training. The control group continued with their regular training. After this 2-wk intervention, the SIT group was allocated to either intervention (n = 7, 1 SIT session/wk as replacement of regular aerobic training) or control (n = 7, regular aerobic training with no SIT sessions) for a 5-wk period (part 2). Pre and post measures were the YoYo Intermittent Recovery Test Level 1 (YYIRL1) and maximal oxygen uptake (VO2max). Results: In part 1, the 2-week SIT intervention had a small beneficial effect on YYIRL1 (17%; 90% confidence limits ±11%), and VO2max (3.1%; ±5.0%) compared with control. In part 2, 1 SIT session/wk for 5 wk had a small beneficial effect on VO2max (4.2%; ±3.0%), with an unclear effect on YYIRL1 (8%; ±16%). Conclusion: Two weeks of SIT elicits small improvements in soccer players' high-intensity intermittent-running performance and VO2max, therefore representing a worthwhile replacement of regular aerobic training. The effectiveness of SIT for maintaining SIT-induced improvements in high-intensity intermittent running requires further research.
Article
The aim of this study was to compare the training effects of a small-sided games (SSG) and a multi-directional sprints intervention on agility and change of direction (COD) ability in male youth-soccer. Thirty-six soccer players (age: 14.2±0.9 years; height: 167.2±5.7 cm; body mass: 54.1±6.3 kg, body fat: 12.5±2.2%) participated in a short-term (6 weeks) randomized parallel fully-controlled training study, with pre-to-post measurements. Players were randomly assigned to two experimental groups: training with pre-planned COD drills (CODG, n=12) or using SSGs (SSGG, n=12) and to a control group (CONG, n=12). Pre and post-training players completed a test battery involving linear sprinting (15 and 30-m sprint), COD sprinting (COD15m, Ball-15m, 10-8-8-10m, zigzag 20m), reactive-agility test (RAT, RAT-ball) and vertical and horizontal jumping (countermovement jump and 5-Jump respectively). A significant (p<0.05) group x time effect was detected for all variables in CODG and SSGG. Improvements in sprint, agility without ball, COD and jumping performances, were higher in CODG than in the other groups. The SSGG improved significantly more (p <0.05) than other groups in agility tests with the ball. The CONG showed significant improvements (p<0.05) on linear sprinting over distance longer than 10m and in all the agility and COD tests used in this study. It is concluded that in male young soccer-players agility can be improved either using purpose built SSG or pre-planned COD sprints. However the use of specifically designed SSG may provide superior results in match relevant variables.
Article
The preseason in soccer is a short period of 6-8 weeks where conditional abilities, technical and tactical elements need to be trained. Therefore, time is lacking to perform long term preparation periods for different abilities, especially endurance training. There is evidence that the implementation of high-intensity shock microcycles in preseason training could be one way to improve physical performance in a short period of time. Therefore, the purpose of the present study was to examine the effects and the sustainability of a high-intensity shock microcycle on soccer specific performance. Over 2 weeks, 12 male soccer players (26.1 ± 4.5 years) performed 12 high-intensity training (HIT) sessions in addition to their usual training. Before (pre), 6 days (6d) and 25 days (25d) after training, subjects performed Counter Movement Jump (CMJ), Repeated-Sprint Ability (RSA) test and Yo-Yo Intermittent Recovery Test Level 2 (YYIR2). Mean sprint time (RSAMean) (cohen's d = -1.15), percentage decrement score (RSAIndex) (cohen's d = -1.99) and YYIR2 (cohen's d = +1.92) improved significantly from pre to 6d. 25d after, values showed a significant reduction for YYIR2 (cohen's d = -0.81) and small to moderate but not significant increase for RSAMean (cohen's d = +0.37) and RSAIndex (cohen's d = +0.7) compared to 6d values. Small but no significant increases were found for CMJ (cohen's d = +0.33) and no significant and substantial changes were found for RSABest (cohen's d = -0.07) from pre to 6d. For competitive soccer players, block periodization of HIT offers a promising way to largely improve RSA and YYIR2 in a short period of time. Despite moderate to large decreases in RSAIndex and YYIR2 performance in the 19 day period without HIT, values still remained significantly higher 25d after the last HIT session compared to pre-values. However, it might be necessary to include isolated high-intensity sessions after a HIT training block in order to maintain the higher level of YYIR2 and RSAIndex performance. Key pointsHIT shock microcycle increases performance in semi-professional soccer players in a short period of time.Despite moderate to large decreases in performance in the 19 day period without HIT, values still remained significantly higher 25d after the last HIT session compared to pre-values.This kind of training block increases YYIR2 performance and the ability to repeated sprints, based on the RSAIndex.
Article
Purpose: To examine whether performance supercompensation during taper is maximized in endurance athletes after experiencing overreaching during an overload training period. Methods: Thirty three trained male triathletes were assigned to either overload training (n=23) or normal training groups (n=10, CTL) during 8 weeks. Cycling performance and maximal oxygen uptake (VO2max) were measured after one-week of moderate training, a 3-week period of overload training and then each week during four-week taper. Results: Eleven of the 23 subjects from the overload training group were diagnosed as functionally overreached after the overload period (decreased performance with concomitant high perceived fatigue, F-OR), while the 12 other subjects were only acutely fatigued (no decrease in performance, AF). According to qualitative statistical analysis, the AF group demonstrated a small to large greater peak performance supercompensation than the F-OR group (2.6 ±1.1%) and the CTL group (2.6 ±1.6%). VO2max increased significantly from baseline at peak performance only in the CTL and AF groups. 60%, 83% and 73% of peak performances occurred within the two first weeks of taper in CTL, AF and OR, respectively. Ten cases of infection were reported during the study with higher prevalence in F-OR (70%) than in AF (20%) and CTL (10%). Conclusion: This study showed that 1) greater gains in performance and V ̇O2max can be achieved when higher training load is prescribed before the taper but not in the presence of F-OR; 2) peak performance is not delayed during taper when heavy training loads are completed immediately prior; and 3) F-OR provides higher risk for training maladaptation, including increased infection risks.