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The aims of this study were: (i) to compare the external and internal load during a 6-aside small-sided game (6v6-SSG) according to age-group (i.e., sensitivity); (ii) to relate these parameters between the 6v6-SSG and official matches (i.e., construct validity); and (iii) to test the reliability of the 6v6-SSG. A total of 51 Brazilian youth soccer players participated in this study (U11 [n=16]; U13 [n=10]; U15 [n=9]; U17 [n=8]; U20 [n=8]). Three experiments were conducted. Experiment A: fifty-one U11 to U20 players were submitted to 6v6-SSGs (n=10 games; two for each age-group). Experiment B: thirty-two players were randomized to also play official matches (n=6 matches). Experiment C: thirty-five youth players played the 6v6-SSG twice for test and retest reliability analysis. External load was obtained using Global Positioning Systems and the internal load parameter was calculated through mean heart rate. Statistical approaches showed progressive increases in all parameters according to categories (U11<U13<U15<U17<U20; p<0.05; ES=0.42˗23.68). Even controlling for chronological age, all parameters showed likely to almost certain correlations between 6v6-SSG and official matches (r=0.25˗0.92). Collectively, the proposed protocol indicates good reliability (CV%=2.0˗12.6; TE%=2.3˗2.7%; ICC=0.78˗0.90). This research suggests that the 6v6-SSG is an alternative tool to indicate match-related physical performance in youth soccer players.
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Journal of Sports Sciences
ISSN: 0264-0414 (Print) 1466-447X (Online) Journal homepage:
Validity and reliability of a 6-a-side small-sided
game as an indicator of match-related physical
performance in elite youth Brazilian soccer players
Rodrigo Aquino, Bruno Melli-Neto, João Victor S. Ferrari, Bruno L. S.
Bedo, Luiz H. Palucci Vieira, Paulo Roberto P. Santiago, Luiz Guilherme C.
Gonçalves, Lucas P. Oliveira & Enrico F. Puggina
To cite this article: Rodrigo Aquino, Bruno Melli-Neto, João Victor S. Ferrari, Bruno L. S. Bedo,
Luiz H. Palucci Vieira, Paulo Roberto P. Santiago, Luiz Guilherme C. Gonçalves, Lucas P. Oliveira
& Enrico F. Puggina (2019) Validity and reliability of a 6-a-side small-sided game as an indicator
of match-related physical performance in elite youth Brazilian soccer players, Journal of Sports
Sciences, 37:23, 2639-2644, DOI: 10.1080/02640414.2019.1608895
To link to this article:
Published online: 07 May 2019.
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Validity and reliability of a 6-a-side small-sided game as an indicator of
match-related physical performance in elite youth Brazilian soccer players
Rodrigo Aquino
, Bruno Melli-Neto
, João Victor S. Ferrari
, Bruno L. S. Bedo
, Luiz H. Palucci Vieira
Paulo Roberto P. Santiago
, Luiz Guilherme C. Gonçalves
, Lucas P. Oliveira
and Enrico F. Puggina
Post-Graduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto,
Faculty of Physical Education, University of Estácio, Ribeirão Preto, São Paulo, Brazil;
School of Physical Education and Sport of Ribeirão
Preto, University of São Paulo, Ribeirão Preto, Brazil;
Human Movement Research Laboratory, Post-graduate Program in Movement Sciences, São
Paulo State University, Bauru, Brazil;
Department of Performance Analysis, Botafogo Football (Soccer) Club, Ribeirão Preto, Brazil
The aims of this study were: (i) to compare the external and internal load during a 6-a-side small-
sided game (6v6-SSG) according to age-group; (ii) to relate these parameters between the 6v6-SSG
and ocial matches; and (iii) to test the reliability of the 6v6-SSG. A total of 51 Brazilian youth
soccer players participated in this study (U11 [n = 16]; U13 [n = 10]; U15 [n = 9]; U17 [n = 8]; U20
[n = 8]). Three experiments were conducted. Experiment A: fty-one U11 to U20 players were
submitted to 6v6-SSGs (n = 10 games; two for each age-group). Experiment B: thirty-two players
were randomized to also play ocial matches (n = 6 matches). Experiment C: thirty-ve youth
players played the 6v6-SSG twice for test and retest reliability analysis. External load was obtained
using Global Positioning Systems and the internal load parameter was calculated through mean
heart rate. Statistical approaches showed progressive increases in all parameters according to
categories (U11< U13< U15< U17< U20; p < 0.05; ES = 0.42˗23.68). Even controlling for chronolo-
gical age, all parameters showed likely to almost certain correlations between 6v6-SSG and ocial
matches (r = 0.25˗0.92). Collectively, the proposed protocol indicates good reliability (CV
%=2.0˗12.6; TE% = 2.3˗2.7%; ICC = 0.78˗0.90).Thisresearchsuggeststhatthe6v6-SSGisan
alternative tool to indicate match-related physical performance in youth soccer players.
Accepted 12 April 2019
Association football; time-
motion analysis; construct
validity; GPS; sports sciences
A variety of methods exist to assess soccer player physical
performance, both outside the match context (Stølen,
Chamari, Castagna, & Wislø,2005), as well as during actual
competitions (Carling, Bloomeld, Nelsen, & Reilly, 2008).
Traditionally, assessments of the former have mainly been
conducted in laboratory settings, e.g., incremental treadmill
tests (Cerda-Kohler et al., 2016), the Wingate Anaerobic Test
(Meckel, Machnai, & Eliakim, 2009), and the maximal anaerobic
oxygen decit test (Andrade et al., 2015). However, to improve
ecological estimations of physical performance, there has
been an emergent trend of using eld tests to assess physical
tness, e.g., Yo-Yo Intermittent Recovery Test (Yo-Yo IR)
(Krustrup et al., 2003), repeated sprint ability test (Impellizzeri
et al., 2008), HoTest (Chamari et al., 2005), and Footeval
(Manouvrier, Cassirame, & Ahmaidi, 2016). In general, these
physical tness tests have various purposes, notably to iden-
tify player individual strengths and weaknesses, investigate
the eects of training interventions, aid in rehabilitation pro-
grams following injury, and prole and monitor youth player
development (Svensson & Drust, 2005).
In order to ensure that the protocol and subsequent infor-
mation gathered from a given physical test have practical
meaning, large relationships between the players physical
tness (derived from laboratory and eld tests) and match
running performance assessments using time-motion analyses
are required, to gain insights into construct validity (Aquino,
Palucci Vieira, de Paula Oliveira, Cruz Gonçalves, & Pereira
Santiago, 2018). In the 1990s, Bangsbo and Lindquist (1992)
were the rst to address this issue in professional soccer
players. Subsequently, there was a rapid increase in similar
research (Buchheit, Mendez-Villanueva, Simpson, & Bourdon,
2010; Castagna, Manzi, Impellizzeri, Weston, & Barbero Alvarez,
2010), mainly related to the growth and availability of a range
of portable match-play tracking equipment, e.g., acceler-
ometers, local position measurement, global positioning sys-
tems (GPS) (Carling et al., 2008). However, Drust, Atkinson, and
Reilly (2007) reported that the match-play running prole is
not-continuous; therefore its patterns defy precise modeling
and are dicult to replicate or predict, hindering the creation
of specic and valid tests outside the match context to eval-
uate soccer players.
Small-sided games (SSGs) have been widely used as
a training methodology in team sports (e.g. soccer)(Hill-Haas,
Dawson, Impellizzeri, & Coutts, 2011). Therefore, since SSGs are
highly specic and frequently used during the season, an
additional practical application could be their use as a tness
indicator, mainly since: (i) more players can be evaluated at
the same time; (ii) SSGs involve technical and tactical
CONTACT Rodrigo Aquino Faculty of Physical Education, University of Estácio: Abrahão Issa Halach, 980, Ribeirânia, Ribeirão
Preto, São Paulo, Brazil
2019, VOL. 37, NO. 23, 26392644
© 2019 Informa UK Limited, trading as Taylor & Francis Group
demands; and (iii) players are performing soccer training dur-
ing the test. Stevens, De Ruiter, Beek, and Savelsbergh (2016)
tested this hypothesis and found that SSGs alone cannot be
used as a valid and reliable tness indicator. However, the
authors used a eld test as the criterion measure (Yo-Yo IR)
to relate the external (e.g., GPS measures) and internal (e.g.,
heart rate) load obtained during the SSGs. With substantial
methodological alterations, the aims of the present study,
therefore, were: (i) to test the sensitivity of the 6v6-SSG to
discriminate external and internal load according to age (U11
to U20); (ii) to evaluate construct validity by relating these
parameters between the 6v6-SSG and ocial matches; and
(iii) to test the reliability of the 6v6-SSG.
A total of 51 Brazilian youth soccer players participated in this
study (U11 [n = 16]; U13 [n = 10]; U15 [n = 9]; U17 [n = 8]; U20
[n = 8]). The sample size was calculated using the correlation
coecients between the Yo-Yo IR2 and running demands
reported in a previous study (Stevens et al., 2016) (statistical
power = 0.85; alpha = 5%; software G*Power, Dusseldorf,
Germany). All measurements were performed in-season as
part of the regular testing program of the teams analyzed.
The players were members of a professional soccer club that
plays in the 1
division of the São Paulo State Championship,
Brazil the leading state-level tournament in the country
(Aquino et al., 2016). This study was approved by the
Research Ethics Committee of the School of Physical
Education and Sport of Ribeirão Preto/USP (CAAE:
61884716.9.0000.5659) and was conducted in accordance
with the Declaration of Helsinki. All participants and their
legal guardians signed an Assent and Consent Term,
Experimental design
Three experiments were conducted. First, all 51 players were
submitted to 6-a-side small-sided games (6v6-SSG) to investi-
gate the sensitivity of the protocol (n = 10 games; two for
each age-group). In this step, we compared external and
internal load parameters between U11 to U20 age-groups
(Experiment A). Second, thirty-two players were randomized
to play ocial matches according to the ocial rules of their
category (U11: n = 16 players, n = 2 matches; U15: n = 8
players, n = 2 matches; U17: n = 8 players, n = 2 matches). This
experiment was performed to test the construct validity of the
6v6-SSG as an indicator of match-related physical performance
(Experiment B). Finally, thirty-ve youth players (U11: n = 16;
U13: n = 10; U15: n = 9) played the 6v6-SSG twice to test and
retest (i.e., after seven days) the reliability analysis (Experiment
C). During all study phases, each test (6vs6-SSG or ocial
matches) was followed by at least 48-hours of recovery. In
addition, all tests were performed on articial grass (~105
x 68 m) between 09:00 AM and 12:00 AM. Prior to the tests,
the players performed a habitual warm-up, consisting of
5-minutes of low-intensity running and 10-minutes of
coordinative running (i.e., skipping, dribbling, anfersen, hop-
serlauf, and kick-out).
6v6-SSG: the protocol was played including goalkeepers, in
6 × 6 min with 90 s of active rest between periods (playing
time: 36 minutes; pitch size = 49 x 25 m). Field size and
playing time were adapted from previous studies (Rebelo,
Silva, Rago, Barreira, & Krustrup, 2016; Stevens et al., 2016).
Consistent coach encouragement was given at all times dur-
ing the 6v6-SSGs. We recommended the players use the 12
21 team formation (i.e., goalkeeper central + external
defender central + external midelder forward). All ocial
match rules were applied with the exception of osideand
yellow/red cards. The coaches organized the players in evenly
balanced teams to maintain the competitiveness of the play-
ing teams. The players were familiar with the 6v6-SSG struc-
ture from their training routines. Goalkeepers could be
involved with the play, but restricted to a maximum of 3 ball
possessions (Stevens et al., 2016). For the reliability analysis,
the teams were composed of the same players (e.g., test: team
A vs. team B; re-test: team A vs. team B).
Ocial matches: all matches were performed during the in-
competitive season. Two matches (i.e., one at home against
top-ranking opponent team [draw]; and one away against
worst-ranking opponent team [won]) were monitored for each
age-group (U11: 20ʹx20ʹwith 10 minutes of passive rest; U15:
30ʹx30ʹwith 15 minutes of passive rest; U17: 40ʹx40ʹwith
15 minutes of passive rest), to prevent the possible confound-
ing factor of situational variables (Aquino, Carling, et al., 2018).
External and internal measures were obtained (see below). The
team formation in all categories was 1442 with occasional
minor variations. In the U11 category, the corner kick was
performed at the intersection between the lateral line and
penalty area (Palucci Vieira, Carling, Barbieiri, Aquino, &
Santiago, 2019). The players were allowed to drink water and
isotonic beverage (6% tangerine-avored carbohydrate-
electrolyte) freely before, during, and after the matches.
External and internal load: external load was measured using
Taiwan). Previous studies have reported good coecients of varia-
tion and error rate, i.e., <5% in all running outputs (Aquino et al.,
2018,2017). In this study, a complementary quality-control assess-
ment was conducted. The players wearing the GPS devices cov-
ered a known distance (calculated by tape measure) at dierent
intensities (6, 13, and 15km·h
). The error rate was <5% for all
running categories. The GPS units were attached to the players
shorts. All players used the same unit throughout the study. The 2D
reconstruction of the geographical coordinates (latitude and long-
itude) of each player at each time point were exported to a CSV
format le using QSports software (Taipei, Taiwan) for later analysis
in Matlab environment (The MathWorks Inc., Natick, USA). The
geographic coordinates were converted to Cartesian coordinates
(xy) and smoothed by a third order Butterworth digital lter
(cutofrequency = 0.4 Hz) for further calculation of the total
distance covered (m), high-intensity running (speed
thresholds individualized according to distance covered > 60% of
peak game speed; U11 [mean14 km.h
], U13 [mean15km.h
U15 [mean16 km.h
], U17 [mean17 km.h
], U20
[mean18 km.h
]), acceleration (2m·s
), and deceleration (
)(Castagna, Varley, Póvoas, & DOttavio, 2017). The mean
heart rate (HR
) was calculated after beat-to-beat monitoring
usingthePolarTeamSystem(PolarElectroOY,Kempele, Finland)
Statistical analysis
Data normality and homogeneity of variance were checked
using the Shapiro-Wilk and Levene tests, respectively. The
p-value threshold was pre-xed at 5% (p < 0.05).
Comparisons between internal and external load according
to age-groups were performed by ANOVA one-way
(Experiment A). When necessary, we used the Bonferroni post-
hoc and log-transformed data. Partial correlations (to control
for the possible eect of chronological age) of Pearson (para-
metric) and Spearman (nonparametric) were used to assess
the relationships between 6v6-SSGs and ocial matches
(Experiment B) according to each age-group. This was per-
formed while controlling for the possible casual relationships
between 6v6- SSGs and ocial matches. The test and retest
reliability of the internal and external load parameters was
tested using the t-test for dependent samples, coecients of
variation (CV%), absolute and typical percentage error (TE),
and intraclass correlation coecient (ICC). The typical percen-
tage error was obtained by dividing the resulting estimate of
the typical error by the mean for the participants in all trials,
then multiplying by 100 (Hopkins, 2000). In addition, the
smallest detectable dierence (SDD) was calculated using the
following equation: SDD = [1.96 · 2 · (SD of the test and retest
dierences · 1ICC)](Haley & Fragala-Pinkham, 2006)
(Experiment C). The analyses were performed using the soft-
ware IBM SPSS Statistics for Windows, version 22.0 (Armonk,
NY: IBM Corporation®). A magnitude-based inferential (MBI)
statistical approach was also used (condence level = 90%,
number of independent inferences = 1; maximum risk of
harm = 0.5%; minimum chance of benet = 25%; benet/
harm odds ratio = 66). Raw data outcomes in standardized
Cohen units were used (Eect Size [ES]). Quantitative chances
of higher or lower dierences were assessed qualitatively as
follows: < 1%, almost certainly not; 1 5 %, very unlikely; 5
25%, unlikely; 25 75%, possibly; 75 95%, likely; 95 99%,
very likely; > 99%, almost certain. If the chance of higher or
lower dierences was > 5%, the true dierence was assumed
as unclear. Otherwise the eect was deemed clear (Hopkins,
Marshall, Batterham, & Hanin, 2009). For greater impact of the
results, only likely chances (> 75%) of dierences were
considered true (Lacome, Simpson, Cholley, Lambert, &
Buchheit, 2018).
Experiment A
Table 1 presents the values of the external and internal load
obtained during the 6v6-SSGs protocol in the analyzed age-
groups (U11 to U20). We observed progressive increases in all
parameters according to categories (U11 < U13 < U15 < U17
< U20; p < 0.05; ES = 0.42˗23.68; likely˗almost certain).
Experiment B
Figure 1 show the correlation coecients (r) observed in the
relationships between 6v6-SSGs and ocial matches con-
trolled by chronological age. All parameters showed likely to
almost certain correlations (r = 0.25˗0.92). The distance cov-
ered in HIR was the best predictor in the relationship between
6v6- SSGs and ocial matches (r = 0.92; almost certain). Within
age-groups (Table 2), U11 and U17 players demonstrated likely
to almost certain relations in all variables (r = 0.46˗0.98), with
the exception of HR
(r = 0.29˗0.54; unclear). The U15
category showed likely to very likely relations for TD, DAcHI,
and HIR (r = 0.42˗0.90), and unclear for DDecHI and HR
(r = 0.004˗0.05).
Experiment C
In general, Table 3 indicates good reliability of the 6v6-SSG. In
relation to CV%, the DAcHI, DDecHI, and HIR demonstrated
greater values (CV% = 8.1˗12.6); however, TD and HR
presented good reproducibility (CV < 5%). All parameters of
external and internal load demonstrated low values of typical
percentage error (TE = 2.3˗2.7%) and high ICC (0.78˗0.89). The
test and retest measures did not dier substantially according
to statistical analysis (p > 0.05; ES = 0.19˗0.25; possibly).
The present investigation was conducted in youth soccer
players with the aim of verifying the sensitivity, validity, and
reliability of a 6v6-SSG as an indicator of match-related physi-
cal performance. The main ndings were: (i) the protocol
presented sensitivity in discriminating age-related perfor-
mance (U11 to U20, see Table 1); (ii) even controlling for
chronological age, all external and internal measures showed
likely to almost certain correlations (see Figure 1); iii) the
Table 1. Mean (standard deviation) of external and internal load obtained during the 6-a-side small-sided games (n = 10 games; playing time: 36 minutes per game)
according to age-groups analyzed (U11 [n = 16 players], U13 [n = 10 players], U15 [n = 9 players], U17 [n = 8 players], U20 [n = 8 players].
Variables U11 U13 U15 U17 U20
TD (m) 2786.3 (304.6) 3421.6 (382.2) 5699.1 (770.2) 6086.0 (214.9) 6416.3 (149.4)
DAcHI (m) 42.1 (15.1) 75.9 (14.6) 191.4 (51.8) 243.9 (40.9) 298.8 (12.4)
DDecHI (m) 24.7 (10.6) 79.3 (17.7) 160.9 (47.4) 258.4 (34) 298.6 (22)
HIR (m) 179 (57.7) 413.8 (137.7) 447 (40.5) 629.3 (68.7) 757.8 (55.5)
(bpm) 160.8 (5.1) 174.5 (4.1) 188.2 (2.4) 189.4 (2.1) 188.4 (3.3)
Note: TD = Total Distance covered; DAcHI = Distance covered at High-Intensity Accelerations (2 m.s
); DDecHI = Distance covered at High-Intensity Deceleration (
2 m.s
); HIR = Distance covered at High-Intensity Running (60.1 to 100% of maximum running speed); HR
= Mean Heart Rate.
distance covered in HIR during the 6v6-SSG explained 84% of
the variance in the distance covered in HIR during the ocial
matches; and (iv) the proposed protocol demonstrated good
reliability (see Table 3).
Sports scientists continuously address physical tests that
are closely linked to match physical demands. Krustrup et al.
(2003) reported that high-intensity running (> 18.0 km·h
covered by the players during matches was correlated to Yo-
Yo test performance (r = 0.71) but not to
or an
incremental treadmill test in professional soccer players. In
addition, two previous recent systematic reviews indicated
trends of associations between several physical tness tests
(e.g., Yo-Yo IR-1, IR-2; multistage tness test, Carminatti test,
20-m shuttle run test, Zig-Zag test, Hotest) and match run-
ning performance (e.g., total distance covered, sprinting, high-
intensity running) in youth soccer players (Palucci Vieira et al.,
2019; Paul & Nassis, 2015). However, one can argue that
laboratory and eld tests per se are not sensitive enough to
prole in-match performance (Stølen et al., 2005). This state-
ment is supported by the apparent lack of laboratory/eld
tests which reproduce construct validity with respect to the
motion types, directions, and intensities corresponding to
match running demands. Therefore, the representativeness
of these tests to predict ocial match physical demands
remains questionable (Drust et al., 2007). Thus, soccer practi-
tioners should use laboratory and eld tests to prescribe
training sessions (e.g., maximal aerobic speed during incre-
mental tests) and not to predict/associate match-related phy-
sical performance.
In contrast, the integrated approach of the SSGs (i.e.,
including physical and tactical/technical aspects compared to
traditional strength and endurance exercises) has been
deemed high enough to promote soccer-specic adaptations
(Hill-Haas, Coutts, Rowsell, & Dawson, 2009; Hill-Haas et al.,
2011), supporting recent criticisms. Recently, Stevens et al.
(2016) observed that running demands during small-sided
games cannot serve as a valid and reliable tness indicator
for professional and amateur soccer players. Nonetheless, in
this study, the 6v6-SSG presented good sensitivity, validity,
and reliability to indicate match-related physical performance
in youth soccer players. First, as expected, we observed pro-
gressive increments in running demands during the 6v6-SSGs
across the age-groups analyzed (U11 to U20). Second, we
veried positive likely to almost certain correlations between
Figure 1. Correlation coecients (± 90% condence interval and quantitative chances) of external and internal loads between 6-a-side small-sided games (n = 6
games) and ocial matches (n = 6 matches) controlled by chronological age. Note: TD = Total Distance covered; DAcHI = Distance covered at High-Intensity
Accelerations (2 m.s
); DDecHI = Distance covered at High-Intensity Deceleration (≥−2 m.s
); HIR = Distance covered at High-Intensity Running (60.1 to 100% of
maximum running speed); HR
= Mean Heart Rate.
Table 2. Correlation coecients (± 90% condence interval and quantitative chances) of external and internal load measures of the 6-a-side small-sided games
(n = 6 games) with ocial matches (n = 6 matches) per age-group.
U11 U15 U17
Variables r ±90% CI QC R ±90% CI QC r ±90% CI QC
TD (m) 0.94 0.06 almost certain 0.62 0.45 likely 0.71 0.39 very likely
DAcHI (m) 0.97 0.03 almost certain 0.42 0.21 likely 0.92 0.14 almost certain
DDecHI (m) 0.98 0.02 almost certain 0.05 0.63 unclear 0.98 0.04 almost certain
HIR (m) 0.96 0.04 almost certain 0.71 0.39 very likely 0.97 0.06 almost certain
(bpm) 0.29 0.40 unclear 0.004 0.63 unclear 0.54 0.50 unclear
Note: TD = Total Distance covered; DAcHI = Distance covered at High-Intensity Accelerations (2m.s
); DDecHI = Distance covered at High-Intensity Deceleration (≥−2 m.s
HIR = Distance covered at High-Intensity Running (60.1 to 100% of maximum running speed); HR
=MeanHeartRate;90%CI=Condence Interval; QC = Quantitative
running outputs in the 6v6-SSG and ocial matches (even
when controlling for chronological age), especially for distance
covered in HIR (explained 84% of the common variance
between 6v6-SSGs and ocial matches). A previous study
demonstrated that HIR is one of the best variables to discri-
minate won vs. lost matches (Aquino et al., 2018); therefore,
the current results demonstrated the construct validity of the
6v6-SSG. Third, collectively the protocol demonstrated good
reliability. Only the external load related to high-intensity
eorts (i.e., DAcHI, DDecHI, and HIR) presented greater values
of CV% (CV% = 8.1˗12.6), in agreement with previous studies
(Hill-Haas et al., 2008; Stevens et al., 2016). These results
promote novel insights for coaches and practitioners, primarily
by providing scientic evidence that the 6v6-SSG can be use-
ful to indicate match-related physical performance in youth
soccer players.
Furthermore, SSGs are frequently used in training routines
during the soccer season. Thus, soccer coaches in youth acad-
emy should implement the 6v6-SSG utilized in this study during
the training session to indicate match-related physical perfor-
mance, without wasting time with extended periods of physical
evaluation. Stevens et al. (2016) complement that SSGs can be
used to signal possible limitations in physical endurance tness
of individual players and in case of doubt, additional maximum
endurance tests (e.g., Yo-Yo IR) can be performed for the
selected player, without having to test all players. However,
the external load parameters of the 6v6-SSG are lower
(~3040% depending on the age-group) compared to ocial
matches. Therefore, coaches and practitioners should not use
the 6v6-SSG structure to simulate an ocial game.
We consider two main limitations of this study. First, we
used a cross-sectional design. Further studies should adopt
repeated assessment during the season and analyze the
consistency of the relationships reported in this
study. Second, in this study it was not possible to separate
the players according to their positional role. In contrast, this
study also has some novel aspects: (i) to the best of our
knowledge, this is the rst study to demonstrate the possi-
ble use of SSGs to indicate match-related physical perfor-
mance in youth soccer players; (ii) external and internal
parameters were considered to dene physical performance;
and (iii) the results proved to be ecient in supporting
conditioning coaches during evaluation periods. In addition,
we highlighted ve crucial points for when clubs opt to use
SSGs as a match-tness indicator: (i) consistent coach
encouragement should be given at all times during the 6v6-
SSG, as this can improve the reliability analysis; (ii) although
the SSGs are better standardized than ocial matches (e.g.,
less position-dependent; Stevens et al., 2016), we recom-
mend players use the 12-21 team formation, and the
same teams in the comparisons between two or more
moments (e.g., test: team A vs. team B; re-test: team A vs.
team B); (iii) all ocial rules should be applied with the
exception of osideandyellow/redcardsincreasing
the representativeness of SSGs with ocial matches; (iv) in
practice, the players often like competitive playing teams,
therefore, the coaches and sports scientists should use
evenly balanced teams (Hill-Haas et al., 2011); and (v)
youth players should be familiar with the 6v6-SSG structure.
Practical application
Physical tness evaluated outside the match context may well
guide training and research, but does not seem to have the best
potential to predict match running demands in youth soccer
players (Aquino, Palucci Vieira, et al., 2018). Our research suggests
that the 6v6-SSG could be an alternative tool to indicate match-
related physical performance in youth soccer players, with greater
specicity and representativeness (i.e., technical-tactical aspects)
than traditional approaches; therefore, coaches and practitioners
should include the 6v6-SSGs in physical assessment routines.
The overall aim of our study was to determine whether the
use of the 6v6-SSG internal and external load can serve as an
indicator of match-related physical performance for youth
soccer players. We performed three experiments to test this
hypothesis: (i) we compared running demands and HR
according to age-groups (U11 to U20); (ii) we checked the
relationships between the 6v6-SSG and ocial matches; and
(iii) we veried the reliability analysis of the protocol used.
Collectively, we demonstrated that the 6v6-SSG presented
sensitivity, validity, and reliability to indicate match-related
physical performance in elite youth Brazilian soccer players.
This study was nanced in part by the Coordenação de Aperfeiçoamento
de Pessoal de Nível Superior - Brasil (CAPES - Finance Code 001), FAPESP
(grant number - 2017/11698-0 and 2014/16164-5), and a Productivity and
Research Exchange with the University of Estácio (Ribeirão Preto; grant
number 2018/19; 2019/20).
Table 3. Reliability analysis for external and internal load obtained during the 6-a-side small-sided games (n = 6 games; playing time: 36 minutes per game).
Variables Test Retest CV% TE ICC SDD ES QC
TD (m) 3716.8 (1300.9) 3522.6 (1354.4) 4.4 (2.8) 86.9 (2.4%) 0.89 339.9 .019 possibly
DAcHI (m) 90.2 (68.2) 98.7 (62.4) 10.0 (8.0) 2.2 (2.3%) 0.79 7.7 0.19 possibly
DDecHI (m) 75.3 (61.7) 84.1 (66.7) 12.6 (13.2) 1.8 (2.3%) 0.80 6.4 0.22 possibly
HIR (m) 315.0 (151.9) 345.2 (163.2) 8.1 (4.7) 8.8 (2.7%) 0.78 33.5 0.21 possibly
(bpm) 171.7 (12.2) 175.0 (14.8) 2.0 (1.7) 4.1 (2.4%) 0.87 15.4 0.25 possibly
Note: TD = Total Distance covered; DAcHI = Distance covered at High-Intensity Accelerations (2m.s
); DDecHI = Distance covered at High-Intensity Deceleration (≥−2 m.s
HIR = Distance covered at High-Intensity Running (60.1 to 100% of maximum running speed); HR
= Mean Heart Rate; CV% = Coecient of Variation; TE = Typical Error
Absolute (relative);ICC=IntraclassCoecient Correlation (all values were almost certain); SDD = Smallest Detectable Dierence; ES = Eect Size; QC = Quantitative Chance.
Disclosure statement
No potential conict of interest was reported by the authors.
Rodrigo Aquino
Bruno L. S. Bedo
Luiz H. Palucci Vieira
Paulo Roberto P. Santiago
Enrico F. Puggina
Andrade, V. L., Zagatto, A. M., Kalva-Filho, C. A., Mendes, O. C.,
Gobatto, C. A., Campos, E. Z., & Papoti, M. (2015). Running-based
anaerobic sprint test as a procedure to evaluate anaerobic power.
International Journal of Sports Medicine,36(14), 11561162.
Aquino, R., Carling, C., Palucci Vieira, L. H., Martins, G., Jabor, G.,
Machado, J., . . . Puggina, E. (2018). Inuence of situational variables,
team formation, and playing position on match running performance
and social network analysis in brazilian professional soccer players.
Journal of Strength and Conditioning Research, epud ahead of print.
doi: 10.1519/JSC.0000000000002725.
PereiraSantiago,P.R.,&Puggina,E.F.(2016). Periodization training focused
on technical-tactical ability in young soccer players positively aects bio-
chemical markers and game performance. Journal of Strength and
Conditioning Research,30(10), 27232732.
Pereira Santiago, P. R. (2018). Relationship between eld tests and match
running performance in high-level young Brazilian soccer players. The
Journal of Sports Medicine and Physical Fitness,58(3), 256262.
Aquino, R., Vieira, L. H. P., Carling, C., Martins, G. H. M., Alves, I. S., &
Puggina, E. F. (2017). Eects of competitive standard, team formation
and playing position on match running performance of Brazilian pro-
fessional soccer players. International Journal of Performance Analysis in
Sport,17(5), 695705.
Bangsbo, J., & Lindquist, F. (1992). Comparison of various exercise tests
with endurance performance during soccer in professional players.
International Journal of Sports Medicine,13(2), 125132.
Buchheit, M., Mendez-Villanueva, A., Simpson, B. M., & Bourdon, P. C.
(2010). Match running performance and tness in youth soccer.
International Journal of Sports Medicine,31(11), 818825.
Carling, C., Bloomeld, J., Nelsen, L., & Reilly, T. (2008). The role of motion
analysis in elite soccer: Contemporary performance measurement tech-
niques and work rate data. Sports Medicine,38(10), 839862.
Castagna, C., Manzi, V., Impellizzeri, F., Weston, M., & Barbero Alvarez, J. C.
(2010). Relationship between endurance eld tests and match perfor-
mance in young soccer players. Journal of Strength and Conditioning
Research,24(12), 32273233.
Castagna,C.,Varley,M.,Póvoas,S.C.A.,&DOttavio, S. (2017). Evaluation of the
MatchExternalLoadinSoccer:MethodsComparison.International Journal
of Sports Physiology and Performance,12(4), 490495.
Cerda-Kohler, H., Burgos-Jara, C., Ramírez-Campillo, R., Valdés-Cerda, M.,
Báez, E., Zapata-Gómez, D., . . . Izquierdo, M. (2016). Analysis of agree-
ment between 4 lactate threshold measurements methods in profes-
sional soccer players. Journal of Strength and Conditioning Research,30
(10), 28642870.
Chamari, K., Hachana, Y., Kaouech, F., Jeddi, R., Moussa-Chamari, I., &
Wislø,U.(2005). Endurance training and testing with the ball in
young elite soccer players. British Journal of Sports Medicine,39(1),
Drust, B., Atkinson, G., & Reilly, T. (2007). Future perspectives in the
evaluation of the physiological demands of soccer. Sports Medicine,37
(9), 783805.
Haley, S. M., & Fragala-Pinkham, M. A. (2006). Interpreting change scores of
tests and measures used in physical therapy. Physical Therapy,86(5),
Hill-Haas, S., Rowsell, G., Coutts, A., & Dawson, B. (2008). The reproduci-
bility of physiological responses and performance proles of youth
soccer players in small-sided games. International Journal of Sports
Physiology and Performance,3(3), 393396.
Hill-Haas, S. V., Coutts, A. J., Rowsell, G. J., & Dawson, B. T. (2009). Generic
versus small-sided game training in soccer. International Journal of
Sports Medicine,30(9), 636642.
Hill-Haas, S. V., Dawson, B., Impellizzeri, F. M., & Coutts, A. J. (2011).
Physiology of Small-Sided Games Training in Football. Sports Medicine,
41(3), 199220.
Hopkins, W. G. (2000). Measures of reliability in sports medicine and
science. Sports Medicine,30(1), 115.
Hopkins, W. G., Marshall, S. W., Batterham, A. M., & Hanin, J. (2009).
Progressive statistics for studies in sports medicine and exercise
science. Medicine & Science in Sports & Exercise,41(1), 313.
Impellizzeri, F., Rampinini, E., Castagna, C., Bishop, D., Ferrari Bravo, D.,
Tibaudi, A., & Wislo,U.(2008). Validity of a repeated-sprint test for
football. International Journal of Sports Medicine,29(11), 899905.
Krustrup, P., Mohr, M., Amstrup, T., Rysgaard, T., Johansen, J.,
Steensberg, A., . . . Bangsbo, J. (2003). The yo-yo intermittent recovery
test: Physiological response, reliability, and validity. Medicine and
Science in Sports and Exercise,35(4), 697705.
Lacome, M., Simpson, B. M., Cholley, Y., Lambert, P., & Buchheit, M. (2018).
Small-Sided Games In Elite Soccer: Does one size t all? International
Journal of Sports Physiology and Performance,13(5), 568576.
Manouvrier, C., Cassirame, J., & Ahmaidi, S. (2016). Proposal for a specic
aerobic test for football players: The Footeval..Journal of Sports
Science & Medicine,15(4), 670677.
Meckel, Y., Machnai, O., & Eliakim, A. (2009). Relationship among repeated
sprint tests, aerobic tness, and anaerobic tness in elite adolescent
soccer players. Journal of Strength and Conditioning Research,23(1),
Palucci Vieira, L. H., Carling, C., Barbieiri, F., Aquino, R., & Santiago, P. R. P.
(2019). Match running performance in young soccer players:
A systematic review. Sports Medicine,49(2), 289318.
Paul, D. J., & Nassis, G. P. (2015). Physical tness testing in youth soccer:
issues and considerations regarding reliability, validity and sensitivity.
Pediatric Exercise Science,27(3), 301313.
Rebelo, A. N. C., Silva, P., Rago, V., Barreira, D., & Krustrup, P. (2016).
Dierences in strength and speed demands between 4v4 and 8v8
small-sided football games. Journal of Sports Sciences,34(24),
Stevens, T. G. A., De Ruiter, C. J., Beek, P. J., & Savelsbergh, G. J. P. (2016).
Validity and reliability of 6-a-side small-sided game locomotor perfor-
mance in assessing physical tness in football players. Journal of Sports
Sciences,34(6), 527534.
Stølen, T., Chamari, K., Castagna, C., & Wislø,U.(2005). Physiology of
soccer: An update. Sports Medicine,35(6), 501536.
Svensson, M., & Drust, B. (2005). Testing soccer players. Journal of Sports
Sciences,23(6), 601618.
... Small-sided games (SSGs) are a widespread form of soccer practice given their capability to simulate both physical and technical-tactical demands at least in part similar to those required in official matches [1][2][3]. In the context of youth soccer, SSGs have been used for various purposes including training prescription, monitoring/testing, and possible talent detection [4][5][6]. However, aside from a number of additional strengths (e.g., exercise specificity and player buy-in), potentially undesired variability may be among the prominent pitfalls of SSGs, particularly when a training program aims to reach specific intensities (i.e., individualisation) and progress across the time. ...
... The within-player variability revealed that heart rate responses are more stable, and the coefficients of variation are, on average, between 6.0 and 11.9% for maximum and mean heart rate. These values are slightly higher than those reported by previous studies on the variability of heart rate responses in the same small-sided games [4,15,23], yet they confirm that physiological responses are relatively reproducible across the days and conditions. The games played no effect on the within-players variability in heart rate mean, although significant differences were found between games on the maximum heart rate. ...
Full-text available
Background: Small-sided games (SSGs) are drill-based and constrained exercises designed to promote a technical/tactical and physiological/physical stimulus on players while preserving some dynamics of the real game. However, as a dynamic game, they can offer some variability making the prediction of the stimulus hardest for the coach. Aim: The purpose of this study was to analyze the between-session and within-player variability of heart rates and locomotor responses of young male soccer players in 3v3 and 5v5 small-sided game formats. Methods: This study followed a repeated-measures study design. Twenty soccer players were enrolled in a study design in which the SSG formats 3v3 and 5v5 were performed consecutively across four days. Twenty under-17 male youth soccer players (16.8 ± 0.4 years old) voluntarily participated in this study. Participants were monitored using a Polar Team Pro for measuring the heart rate mean and maximum, distances covered at different speed thresholds, and peak speed. Results: Between-players variability revealed that maximum heart rate was the outcome with a smaller coefficient of variation (3v3 format: 3.1% to 11.1%; 5v5 format: 6.6% to 15.2%), while the distance covered at Z5 (3v3 format: 82.5% to 289.8%; 5v5 format: 94.0% to 221.1%). The repeated measures ANOVA revealed that the four games tested were different in the within-player variability considering the maximum heart rate (p = 0.032), total distance (p < 0.001), and distances at zone 1, 2, and 5 of speed (p < 0.001). Conclusions: The smaller small-sided game tested promotes greater within-player variability in locomotor demands while promoting smaller within-player variability heart rate responses. Possibly, 5v5 is more recommended to stabilize the locomotor demands, while the 3v3 is recommended to stabilize the heart rate stimulus.
... No entanto, devido a dinâmica e imprevisibilidade, é esperado que esses jogos promovam uma considerável variabilidade intra e inter-sessões 1 em suas respostas agudas e crônicas ao treinamento . Por exemplo, estudos mostram que as respostas da frequência cardíaca apresentam menor variabilidade (Aquino et al., 2019;Bredt et al., 2016;Stevens et al., 2016), enquanto as concentrações de lactato sanguíneo e o esforço percebido são mais variáveis . No caso das demandas físicas, estudos revelaram que a distância total percorrida durante os jogos reduzidos tem variabilidade intra e inter-sessões relativamente baixa (Aquino et al., (Aquino et al., 2019;Stevens et al., 2016;Younesi et al., 2021). ...
... Por exemplo, estudos mostram que as respostas da frequência cardíaca apresentam menor variabilidade (Aquino et al., 2019;Bredt et al., 2016;Stevens et al., 2016), enquanto as concentrações de lactato sanguíneo e o esforço percebido são mais variáveis . No caso das demandas físicas, estudos revelaram que a distância total percorrida durante os jogos reduzidos tem variabilidade intra e inter-sessões relativamente baixa (Aquino et al., (Aquino et al., 2019;Stevens et al., 2016;Younesi et al., 2021). ...
Os jogos reduzidos, assim como as partidas oficiais de futebol podem ser considerados sistemas dinâmicos que envolvem as relações entre duas equipes sob influência de diferentes fatores posicionais e contextuais (Clemente, 2020). Por causa disso, todos os cenários de treinamento envolvem algum nível de imprevisibilidade, e tal imprevisibilidade naturalmente leva a um aumento na variabilidade dos estímulos (Hill-Haas, Rowsell, et al., 2008). Essa variabilidade é essencial para o desenvolvimento do aspecto tático e técnico dos (as) jogadores (as). Contudo, uma grande variabilidade nas demandas físicas pode não ser a melhor opção para o desenvolvimento do aspecto físico e fisiológico. Um nível de variabilidade mais ajustado pode ser melhor ao considerar que a carga de treinamento deve respeitar os princípios da sobrecarga e da individualidade (Gabbett, 2016). Diversos constrangimentos podem ser manipulados pelos(as) treinadores(as) durante a aplicação de jogos reduzidos, de acordo com o objetivo da sessão de treinamento. Este modelo contempla as restrições da tarefa (por exemplo, número de jogadores/as, dimensões do campo, regras, presença ou não de alvos/coringas/apoios/goleiros, relações esforço:pausa, abordagem de feedbakcs do/a treinador/a, etc.), do ambiente (por exemplo, tipo de terreno [grama natural ou artificial], marcações no campo para delimitação do espaço de jogo [cones, faixas], temperatura, altitude, etc.), e do indivíduo (por exemplo, idade, nível de desempenho, relações afetivas/sociais, etc.) (Clemente et al., 2021). A manipulação desses constrangimentos promovem variações nas demandas fisiológicas, físicas, técnicas e táticas, o que pode oportunizar ou ameaçar o desenvolvimento dos(as) jogadores(as) (Clemente, 2020; Clemente et al., 2021) De fato, alguns protocolos de treinamento usam os jogos reduzidos para promover o desenvolvimento físico dos(as) jogadores(as) (Moran et al., 2019). No entanto, devido a dinâmica e imprevisibilidade, é esperado que esses jogos promovam uma considerável variabilidade intra e inter-sessões em suas respostas agudas e crônicas ao treinamento (Clemente et al., 2020). Por exemplo, estudos mostram que as respostas da frequência cardíaca apresentam menor variabilidade (Aquino et al., 2019; Bredt et al., 2016; Hill-Haas, Rowsell, et al., 2008; Stevens et al., 2016), enquanto as concentrações de lactato sanguíneo e o esforço percebido são mais variáveis (Hill-Haas, Coutts, et al., 2008; Hill-Haas, Rowsell, et al., 2008). No caso das demandas físicas, estudos revelaram que a distância total percorrida durante os jogos reduzidos tem variabilidade intra e inter-sessões relativamente baixa (Aquino et al., 2019; Younesi et al., 2021), enquanto as distâncias percorridas em alta velocidade (por exemplo, > 19,8 km/h) têm variabilidade relativamente alta (Aquino et al., 2019; Stevens et al., 2016; Younesi et al., 2021). O número de pesquisas que investigaram a variabilidade do desempenho técnico-tático intra e inter-sessões de jogos reduzidos é consideravelmente menor em comparação aos estudos que analisaram as respostas fisiológicas e físicas. Contudo, os resultados sugerem alta variabilidade entre os resultados técnicos e táticos (Bredt et al., 2016; Clemente et al., 2019). Por exemplo, um estudo recente mostrou que a eficiência tática defensiva dos jogadores foi maior na última série em comparação com a primeira de jogos reduzidos no formato 3 vs. 3 + Goleiros (4 séries de 4 minutos em um campo de 36 metros de comprimento por 27 metros de largura) (Praça et al., 2020). Esses resultados reforçam a exigência de auto-organização dos(as) jogadores(as) durante os jogos para resolverem de maneira eficiente e eficaz os problemas emergentes. Além disso, sob a ótica do desempenho técnico-tático, outras análises qualitativas podem ser observadas e interpretadas durante os jogos reduzidos. A variabilidade de ações relacionadas a ideia e objetivo do jogo pode complementar as evidências científicas sobre esse tema. Ou seja, a observação e interpretação do(a) treinador(a) em relação ao desempenho dos(as) jogadores(as) intra e inter-sessões de jogos reduzidos pode ser pautada no cumprimento ou não da ideia e objetivo do jogo, mesmo que resolvendo os problemas de variadas formas. Portanto, é importante uma análise sistêmica sobre as respostas dos(as) jogadores(as), considerando variáveis quantitativas e qualitativas. Neste capítulo iremos oferecer subsídios teóricos e práticos para os profissionais do futebol sobre a variabilidade de respostas intra e inter-sessões de treinamento organizadas por meio de jogos reduzidos.
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Background: Velocity and accelerations have been highlighted as the most critical variables in soccer. However, there is a consensus gap in defining different levels of effort. Aim: The purpose of this systematic review is to identify if it is a consensus in those articles that proposed a threshold to establish (i) movement intensity at different velocities using tracking systems and (ii) accelerations using inertial measurement units, classifying the justification methods. For Peer Review Method: A systematic review of Cochrane Library, EBSCO, PubMed, Scielo, Scopus, SPORTDiscus, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: From the 1983 studies initially identified, 39 were thoroughly reviewed, and their outcome measures were extracted and analyzed. Conclusion: The 40m maximal linear sprint and physical fitness tests are the most commonly used methods to generate speed and acceleration thresholds in soccer. However, there is substantial heterogeneity in locomotor test procedures and workload zones established from these performance data. Studies diverged when considering the use of individualized thresholds. The low sampling rate (≤ 10 Hz) in the publications calculating acceleration and deceleration demands should also be interpreted cautiously. The present study collected evidence to help professionals process and interpret external load data. More interventional work is needed to confirm the value of fitness-based individualizations. Key words: team sport; data analysis; performance; high-intensity; speed
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Background Sided games (i.e., small sided, medium sided, large sided) involve tactical, technical, physical, and psychological elements and are commonly implemented in soccer training. Although soccer sided-games research is plentiful, a meta-analytical synthesis of external load exposure during sided games is lacking. Objective The objective of this systematic review and meta-analysis was to: (1) synthesize the evidence on high-speed and sprint running exposure induced by sided games in adult soccer players, (2) establish pooled estimates and intra-individual reliability for high-speed and sprint running exposure, and (3) explore the moderating effects of game format and playing constraints. Methods A literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Four databases (PubMed/MEDLINE, Scopus, SPORTDiscus, Web of Science Core Collection) were systematically searched up to 25 January, 2022. Eligibility criteria were adult soccer players (population); training programs incorporating sided games (intervention); game manipulations including number of players, pitch dimension, and game orientation (comparator); and high-speed, very high-speed, and sprint relative (m⋅min−1) running distances and associated intra-individual reliability (outcome). Eligible study risk of bias was evaluated using RoBANS. Pooled estimates for high-speed and sprint running exposure, and their intra-individual reliability, along with the moderating effect of tracking device running velocity thresholds, pitch dimension (i.e., area per player), and game orientation (i.e. score or possession), were determined via a multi-level mixed-effects meta-analysis. Estimate uncertainty is presented as 95% compatibility intervals (CIs) with the likely range of relative distances in similar future studies determined via 95% prediction intervals. Results A total of 104 and 7 studies met our eligibility criteria for the main and reliability analyses, respectively. The range of relative distances covered across small-sided games, medium-sided games, and large-sided games was 14.8 m⋅min−1 (95% CI 12.3–17.4) to 17.2 m⋅min−1 (95% CI 13.5–20.8) for high-speed running, 2.7 m⋅min−1 (95% CI 1.8–3.5) to 3.6 m⋅min−1 (95% CI 2.3–4.8) for very high-speed running, and 0.2 m⋅min−1 (95% CI 0.1–0.4) to 0.7 m⋅min−1 (95% CI 0.5–0.9) for sprinting. Across different game formats, 95% prediction intervals showed future exposure for high-speed, very high-speed running, and sprinting to be 0–46.5 m⋅min−1, 0–14.2 m⋅min−1, and 0–2.6 m⋅min−1, respectively. High-speed, very high-speed running, and sprinting showed poor reliability with a pooled coefficient of variation of 22.8% with distances being moderated by device speed thresholds, pitch dimension, and game orientation. Conclusions This review is the first to provide a detailed synthesis of exposure and intra-individual reliability of high-speed and sprint running during soccer sided games. Our estimates, along with the moderating influence of common programming variables such as velocity thresholds, area per player, and game orientation should be considered for informed planning of small-sided games, medium-sided games, and large-sided games soccer training. Clinical Trial Registration Open Science Framework available through
This study investigated the test-retest reliability in both within and between-session reliability of commonly adopted tactical measures in small-sided games. GPS-based and observational tactical variables from three instruments were collected from a 4 versus 4 small-sided game played by 16 U-17 elite players. The games were played three times in the same training session (within-session reliability) and repeated after 1 week (between-session reliability). The reliability of the data was analyzed by calculating the Intraclass Correlation Coefficient (ICC) and the Standard Error of Measurement (SEM) for all dependent variables. Results showed good-to-excellent reliability and a low error for GPS-based tactical variables, mainly the width and length positioning (ICC > 0.9, SEM < 10%, p < 0.05). Observational variables showed poor-to-moderate reliability, except the offensive performance measured by the FUT-SAT in the between-session analysis. It is concluded that GPS-based tactical variables show acceptable reliability and might be used for talent identification and training outputs assessment in soccer. The variability inherent to small-sided games is associated with both the open nature of the task and poor measurement quality. Increasing the quality of the instruments will likely provide a better view of the actual variability of this training tool.
This study examines how exertion during matches affects participants' physical capacity and match performance. The study included 13 elite football league players (21 6 0.7 years old; height, 181.1 6 8.98 cm; body mass, 74.7 6 8.1 kg) and used global positioning system (GPS) data collected during 12 official matches. Four matches after the first Yo-Yo IR1 test, four matches before the second Yo-Yo IR1 test, and four matches after the second Yo-Yo IR1 test are examined. Sprint count per minute (SC) (N/min), (. 19 km/h), p \ 0.030; distance covered at zone 4-6 per minute DCZ4 (km/h/ min), (18-24 km/h), p \ 0.00; distance covered at zone 4-6 per minute DCZ5 (km/h/min), (24-30 km/h), p \ 0.001; and distance covered at zone 4-6 per minute DCZ6 (km/h/min), (30-39 km/h), p \ 0.001 were recorded. According to the values obtained before the tests, the match data show a decreasing trend in the following weeks. Furthermore, the relationship between physical performance values and tests is determined (average speed (AS) (km/h), r = 0.64; maximum speed (MS) (km/h), r = 0.50; DCZ4 (km/h/min), r = 0.89; DCZ5 (km/h), r = 0.81). As a result, time-dependent changes in intermittent endurance capacity during matches validated in-game running kinematics. This indicates the Yo-Yo IR1's robustness as a fitness marker, and its capacity to help practitioners preview longitudinal variations in locomotor behavior during matches. Athletes who show a high degree of asymmetry in official matches seem to exhibit a strong ability to resist fatigue during testing.
This study aimed to analyze whether there are differences and associations in the physical responses in international-level cerebral palsy (CP) footballers between official matches and 2vs.2 small-sided games (2v2-SSGs). One hundred and seventy international CP footballers participated in this study during three international championships. The physical responses of mean (Velmean) and maximum velocities, total distance, distance covered at different intensities, short-term actions, and player load were collected during 2v2-SSGs and the real competition. The Velmean, total distance, jogging, medium intensity, and high-intensity distances and the number of moderate/high accelerations, decelerations and player load were relatively higher in the 2v2-SSGs than in the official matches. Even though the 2v2-SSG could become an appropriate drill to include during the classification process, due to the differences between a 2v2-SSG and the official competition it is necessary to deepen the scientific knowledge for developing observation methods during the real competition to strengthen the relationships between eligible impairments and activity limitation.
Quais perspectivas teóricas sustentam a utilização dos jogos como meio de ensino e treinamento no esporte? Quais contextos de aprendizagem são vivenciados pelos (as) jogadores (as) ao longo do seu processo de desenvolvimento? Como organizar e sistematizar o processo de ensino e treinamento a longo prazo por meio de jogos? O que são jogos reduzidos? Quais são as possibilidades e potencialidades da utilização destas tarefas de treino no desenvolvimento dos aspectos tático-técnico-físicos no futebol e futsal? Quais são as limitações na utilização desse meio de ensino e treinamento? Essas são as perguntas norteadoras que buscaremos responder ao longo deste capítulo. A intervenção do (a) treinador (a) durante os processos de organização, sistematização, aplicação e avaliação das práticas pedagógicas são sustentadas por uma visão de mundo, influenciada por diferentes paradigmas e teorias do conhecimento (GALATTI et al., 2014; BETTEGA et al., 2021). Essa sustentação teórica pode gerar várias implicações no processo de ensino e treinamento do esporte, como por exemplo, treinos predominantemente fundamentados no desenvolvimento técnico de forma descontextualizada do jogo, buscando a repetição de movimentos para a automação, estimulando o desenvolvimento de jogadores (as) com um repertório pobre de possibilidades de respostas e com alto grau de dependência ao comando do (a) treinador (a) (MENEZES; MARQUES; NUNOMURA, 2014; REVERDITO; SCAGLIA, 2020). Por outro lado, defendemos na nossa intervenção teórico-prática um paradigma emergente que é sustentado por uma visão de mundo interacionista, que deu lugar a diferentes abordagens (destacamos as abordagens construtivista, ecológica e sociocultural) e modelos de ensino pautados no jogo (SCAGLIA; REVERDITO; GALATTI, 2014). Como resultado, entendemos que o processo de ensino, vivência, aprendizagem e treinamento no futebol e futsal deve ser predominantemente pautado no jogo e centrado no (a) jogador (a), possibilitando o desenvolvimento de competências essenciais para um jogo eficaz (SCAGLIA et al., 2013), com as ações de jogo expressas em uma relação mútua entre os aspectos tático-técnico-físicos. Nesses pressupostos, o (a) treinador (a) não deve ser apenas um observador do jogo, nem um “comandante” do jogo, oferecendo muitas vezes respostas pré-determinadas aos problemas que dali emergem. Um bom treino pautado no jogo, deve ser centrado na aprendizagem, cujos principais papéis do (a) treinador (a) é gerar situações problemas, mediar trocas de conhecimento e possibilitar uma aprendizagem significativa, muitas vezes descentralizando o treino e estimulando um maior engajamento do (a) jogador (a), os(as) quais assumem um papel ativo no seu processo de aprendizagem (SCAGLIA, 2004; MACHADO et al., 2019a). Nessa perspectiva, não importa, apenas, entender as possibilidades do jogo enquanto meio de ensino e treinamento dos aspectos tático-técnico-físicos, mas devemos considerar também suas potencialidades. Por exemplo, durante um jogo, determinadas restrições da tarefa (exemplo, dimensão do campo/quadra) influenciam nas dimensões tática-técnica-físicas dos (as) jogadores (as). Isso pode ser entendido como possibilidades (conteúdos evidentes) de manipulação dessas restrições para atingir determinados objetivos. Contudo, as diferentes potencialidades de aprendizagem (conteúdos latentes) emergem das interações mútuas das restrições da tarefa com os jogadores (as), seus esquemas motrizes (restrições do indivíduo) e o ambiente (restrições do ambiente) (SCAGLIA et al., 2021). Portanto, podemos sustentar a ideia de que, para além dos conteúdos evidentes que se presente enfatizar durante as sessões de treino com jogos (possibilidades de ensino), precisamos considerar as necessidades/características dos (as) jogadores (as) para promover uma aprendizagem significativa (potencialidades de ensino). Nesse sentido, é papel do (a) treinador (a) manipular cuidadosamente condicionantes do jogo para ajustá-lo às demandas intrínsecas dos (as) jogadores (as) e aos conteúdos a serem enfatizados. Logo, implementar um processo de ensino, vivência, aprendizagem e treinamento no futebol/futsal que seja pautado no jogo e centrado no (a) jogador (a) exige que o (a) treinador (a) esteja muito bem preparado (a) para gerir um conjunto de restrições que interagem mutuamente para potencializar a aprendizagem de seus (as) jogadores (as). Ao ler esse capítulo, os (as) treinadores (as) e pesquisadores (as) devem entender que nosso objetivo é engendrar sobre as possibilidades e potencialidades dos jogos como meio de ensino e treinamento do futebol e futsal, especialmente no desenvolvimento dos aspectos tático-técnico-físicos. Entendendo que cada jogo é um jogo, respeitando sua característica auto-afirmativa (SCAGLIA, 2011), não podemos generalizar as respostas sobre as manipulações das restrições da tarefa, indivíduo e ambiente apresentadas para todos os contextos de prática do futebol/futsal. Cabe a sensibilidade pedagógica do treinador (a) para ajustar e adaptar em “tempo real” as atividades de treino de acordo com os objetivos pretendidos e com as demandas dos (as) seus (suas) jogadores (as). Além disso, buscando ser fiel ao paradigma que nos sustenta, organizamos este capítulo de modo a destacar as relações entre as possibilidades táticas, técnicas e físicas geradas a partir da manipulação de diferentes restrições da tarefa, bem como destacar as diferentes potencialidades proporcionadas pelos jogos reduzidos. Destacamos também diferentes formas de se organizar um microciclo de treino com jogos, bem como apontamos as principais limitações na utilização de jogos reduzidos ao longo do processo de ensino e treinamento.
As utilizações de sistemas tecnológicos têm vindo a possibilitar um aumento da compreensão sobre os parâmetros de carga externa (demandas físicas) associadas ao jogo de futebol (PALUCCI VIEIRA et al., 2019b; SAR MENTO et al., 2018). A possibilidade de observar, descrever, caracterizar e inferir tendo por base os padrões de corrida e ação realizadas pelos futebolistas, possibilita, não apenas um entendimento sobre as exigências do jogo (por exemplo, totais, médias e picos de demandas físicas em casos possíveis) (WASS et al., 2020) e sua variação de contexto para contexto (CASTELLANO et al., 2011; OLIVA-LOZANO et al., 2020; PAUL et al., 2015), e atleta para atleta (AQUINO; VIEIRA et al., 2017; OLIVA-LOZANO et al., 2020), como também, as implicações para o ajustamento e individualização do treinamento esportivo (CLEMENTE et al., 2019a; OWEN et al., 2017). O presente capítulo procurará dar uma visão global ao leitor de como a análise do desempenho de corrida poderá ser um fator determinante na adequação do planejamento do treinamento de futebol. Na primeira seção, será abordado o processo de evolução dos sistemas de análise do desempenho de corrida. Na sequência, serão caracterizadas as demandas de corridas durante as partidas de futebol de jovens futebolistas e de profissionais, considerando os sexos feminino e masculino. Na terceira seção, mostraremos as relações entre as demandas durante a partida e a aptidão atlética, considerando as suas implicações para a avaliação. Na quarta seção, procurar-se-á analisar o erro dos distintos sistemas de aquisição de dados posicionais e como se pode garantir a acurácia e precisão das medidas. Na quinta seção, demonstrar-se-ão exemplos de como o conhecimento das demandas de corrida durante a partida poderão modelar o treinamento, considerando principalmente diversos fatores contextuais. Finalmente na sexta e última seção deste capítulo, apresentar-se-ão considerações finais, sintetizando as principais contribuições sobre o tema.
This systematic review with a meta-analysis was conducted to compare the effects of small-sided games (SSGs)-based interventions with the effects of running-based high-intensity interval training (HIIT) interventions on soccer players’ repeated sprint ability (RSA). The data sources utilized were Web of Science, Scopus, SPORTDiscus, and PubMed. The study eligibility criteria were: (i) parallel studies (SSG-based programs vs. running-based HIIT) conducted in soccer players with no restrictions on age, sex, or competitive level; (ii) isolated intervention programs (i.e., only SSG vs. only running-based HIIT as individual forms) with no restrictions on duration; (iii) a pre–post outcome for RSA; (iv) original, full-text, peer-reviewed articles written in English. An electronic search yielded 513 articles, four of which were included in the present study. There was no significant difference between the effects of SSG-based and HIIT-based training interventions on RSA (effect size (ES) = 0.30; p = 0.181). The within-group analysis revealed no significant effect of SSG-based training interventions (ES = −0.23; p = 0.697) or HIIT-based training interventions (ES = 0.08; p = 0.899) on RSA. The meta-comparison revealed that neither SSGs nor HIIT-based interventions were effective in improving RSA in soccer players, and no differences were found between the two types of training. This suggests that complementary training may be performed to improve the effects of SSGs and HIIT. It also suggests that different forms of HIIT can be used because of the range of opportunities that such training affords.
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Background: To date, athletic performance has been extensively assessed in youth soccer players through laboratory and field testing. Only recently has running performance via time-motion analysis been assessed during match-play. Match running data are often useful in a practical context to aid game understanding and decision-making regarding training content and prescriptions. A plethora of previous reviews have collated and appraised the literature on time-motion analysis in professional senior players, but none have solely examined youth players. Objective: The aim of the present systematic review was to provide a critical appraisal and summary of the original research articles that have evaluated match running performance in young male soccer players. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, literature searches were performed in four databases, namely, PubMed, ISI Web of Science, SPORTDiscus and SciELO, using the descriptors “soccer”, “football”, “young”, “youth”, “junior”, “physical performance”, “running performance”, “match running performance”, “movement patterns”, “time-motion analysis”, “distances covered”, “activity profile”, “work rate”, “match analysis”, and “match performance”. Articles were included only if they were original articles written in the English language, studied populations of male children and/or adolescents (≤ 20 years of age), were published/ahead of print on or before December 31, 2017, and showed at least one outcome measure regarding match running performance, such as total distance covered, peak game speed or indicators of activities performed at established speed thresholds. Results: A total of 5801 records were found. After removal of duplicates and the application of the exclusion and inclusion criteria, a total of 50 articles were included (n = 2615 participants). Their outcome measures were extracted and findings were synthesized. The majority of the reviewed papers covered the European continent (62%) and used global positioning systems (GPS) (64%). Measurement error of the tools used to obtain position data and running metrics was systematically overlooked among the studies. The main aims of studies were to examine differences across playing positions (20%), age groups (26%) and match halves (36%). Consistent findings pointed to the existence of positional role and age effects on match running output (using fixed running speed thresholds), but there was no clear consensus about reductions in activity over the course of match-play. Congested schedules negatively affected players’ running performance. While over 32% of all studies assessed the relationships between match running performance and physical capacity, biochemical markers and body composition, ~70% of these did not account for playing position. Conclusions: This review collated scientific evidence that can aid soccer conditioning professionals in understanding external match loads across youth categories. Coaches working with youth development programs should consider that data derived from a given population may not be relevant for other populations, since game rules, match format and configuration are essentially unstandardized among studies for age-matched players. Despite limited evidence, periodization training emphasizing technical-tactical content can improve match running performance. Occurrence of acute and residual impairments in the running performance of young soccer players is common. Prescription of postmatch recovery strategies, such as cold-water immersion and spa treatment, can potentially help reduce these declines, although additional research is warranted. This review also highlighted areas requiring further investigation, such as the possible influence of environmental and contextual constraints and a more integrative approach combining tactical and technical data.
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The purpose of this study was to investigate the independent and interactive effects of situational variables, opposition team formation, and playing position on running performance and network analysis in Brazilian professional soccer players (n=22). Global Positioning System technology was used to determine total distance covered, mean speed, maximum running speed, and distance covered in six speed ranges. Social network analysis was used to assess interpersonal coordination (team interactions characterized as successful passes (n=3033) between teammates). Observations of match running performance (n=129), and network analysis (n=108) were obtained. The main results were: (i) no interactive effects between team formation and playing position were observed for running and network variables (unclear to possibly); (ii) matches played at home or against 'weaker' opponents presented greater running demands and individual/global metrics of network analysis (likely to almost certain); (iii) match outcome demonstrated influence only for running performance; matches in which the reference team won resulted in higher values than in lost matches; (iv) when the reference team competed in 1˗4˗4˗2 formation, this resulted in greater running demands than 1˗4˗2˗3˗1 formation (likely to almost certain); (v) reduced values of running performance variables were reported in central defenders compared to other positions. Central/external midfielders reported greater closeness/betweenness centrality, out-degree and eigenvector compared to central/external defenders and forwards (likely to almost certain). The results from this study provide practical information to potentially impact on physical, tactical and technical training.
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This study examined the effects of competitive standard, team formation and playing position on match running performance in a Brazilian professional soccer team. Performance was investigated in 36 players in 48 matches at three competitive standards: 1 st São Paulo State Championship; 3 rd and 4 th Brazilian leagues. Global Positioning System technology was used to determine total distance covered (TD), maximal running speed (MRS), mean speed (S MEAN) and frequency of high-intensity activities (HIA). Data were compared across competitive standards, team formations and playing positions. Magnitude-based inferences showed greater values for TD, S MEAN and HIA (likely to almost certain) in the lower national (3 rd , 4 th Brazilian) versus the top state division (1 st São Paulo). Higher values for all variables were reported for the 1–4–3–3 versus the 1–4–4–2 formation (likely to almost certain). External defenders/midfielders and forwards reported greater values (likely to almost certain) versus central defenders/midfielders, especially in HIA. Linear regression analyses showed that playing position demonstrated a higher relative contribution to the variance in MRS (24%) and HIA (29%) compared to team formation (16% and 25%, respectively). In a Brazilian professional soccer team, match running performance was dependent upon competitive standard, playing formation and playing position.
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Purpose: To compare the peak intensity of typical Small Sided Games (SSGs) with those of official matches in terms of running demands and mechanical work over different rolling average durations and playing positions. Method: Data were collected in 21 players (25±5 y, 181±7 cm, 77±7 kg) belonging to an elite French football team. SSG data were collected over two seasons during typical training sessions (249 files, 12±4 per player) and official matches (n=12). Players' locomotor activity was recorded using 15-Hz GPS. Total distance (TD, m), high-speed distance (HS, distance above 14.4 km.h-1, m) and mechanical work (MechW, a.u) were analysed during different rolling average periods (1 to 15 min). The SSGs examined were 4v4+Goal Keepers (GKs), 6v6+GKs, 8v8+GKs and 10v10+GKs. Results: Peak TD and HS during 4v4, 6v6 and 8v8 were likely-to-most likely largely lower than during matches (ES: -0.59,±0.38 to -7.36,±1.20). MechW during 4v4 was likely-to-most likely higher than during matches (1-4-min; 0.61±,0.77 to 2.30±,0.64). Relative to their match demands, central defenders (CD) performed more HS than other positions (0.63±,0.81 to 1.61±,0.52) during 6v6. Similarly, central midfielders (CM) performed less MechW than the other positions during 6v6 (0.68,±0.72 to 1.34,±0.99) and 8v8 (0.73,±0.50 to 1.39,±0.32). Conclusion: Peak locomotor intensity can be modulated during SSGs of various formats and durations to either over- or underload match demands, with 4v4 placing the greatest and the least emphasis on MechW and HS, respectively. Additionally, CD and CM tend to be the most and least overloaded during SSGs, respectively.
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BACKGROUND: The main aim of this study was to analyse the relationship between field tests and match running performance using computational tracking technology in high-level young Brazilian soccer players. METHODS: Twenty-five young male Brazilian soccer players participated in this study (U-15, n = 13; U-17, n = 12). In the same week the players were submitted to field tests and actual matches. The field tests were: Maximum Speed (10m-30m), Zig-Zag, Running-based Anaerobic Sprint Test, and Yo-Yo Intermittent Recovery Test level 1. Additionally, participants performed actual soccer match-play. Match running performance was collected using a fixed video-camera. Subsequently, computerized tracking video-analysis (30 Hz) was utilized to identify each physical performance indicator. Pearson’s correlation and linear regression were used for statistical analysis. RESULTS: The results showed that the majority of field tests were not related to match running performance. The Zig-Zag Test, Running-based Anaerobic Sprint Test, and Yo-Yo Intermittent Recovery Test level 1 seem to be the most specific tests (r = 0.41-0.47), however the explanatory powers of these field tests in relation to match running performance were low (R2 = 17-22%). CONCLUSION: Assessment of match running performance should be included in the evaluation periods of young soccer players, together with the most specific tests reported. Key-words: association football, computational tracking, GoPro®, physical performance.
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The aim of this study was to evaluate the reproducibility and validity of the " Footeval " test, which evaluates football players' aerobic level in conditions close to those of football practice (intermittent, including technical skills). Twenty-four highly trained subjects from an elite football academy (17.8 ± 1.4 years, 5 training sessions per week) performed two Footeval sessions in a period of 7 days. Physiological variables measured during these sessions (VO 2 max 58.1 ± 5.6 and 58.7 ± 6.2 ml • min-1 • kg-1 ; RER 1.18 ± 0.06 and 1.19 ± 0.05; LaMax 11.0 ±1.4 and 10.8 ±1.1 µmol • L-1 ; HRmax 194 ± 6 and 190 ± 7 b • min-1 ; Final step 10.71 ± 1.2 and 10.83 ± 1.13 and the RPE = 10) highlighted maximal intensity and confirmed that players reached physiological exhaustion. Comparison of values measured in both sessions showed large to very large correlations (Final level; 0.92, VO 2 max; 0.79, HRmax; 0.88, LaMax; 0.87) and high ICC (Final level; 0.93, VO 2 max; 0.87, HRmax; 0.90, LaMax; 0.85) except for RER (r = 0.22, ICC = 0.21). In addition , all subjects performed a time limit (Tlm) exercise with intensity set at maximal aerobic specific speed + 1 km • h-1 , in order to check the maximal value obtained during the Footeval test. Statistical analysis comparing VO 2 max, HRmax and RER from the Footeval and Tlm exercise proved that values from Footeval could be considered as maximal values (r for VO 2 max; 0.82, HRmax; 0.77 and ICC for VO 2 max; 0.92, HRmax; 0.91). This study showed that Footeval is a reproducible test that allows maximal aerobic specific speed to be obtained at physiological exhaustion. Moreover, we can also affirm that this test meets the physiological exhaustion criteria as defined in the literature (RER ≥ 1, 1; LaMax ≥ 8 µmol • L-1 ; HR = HRmax; no increase of VO2 despite the increase of speed; RPE =10).
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Purpose: The aim of this study was to test the interchangeability of two match-analysis approaches for external-load detection considering arbitrary selected speeds and metabolic power (MP) thresholds in male top-class level soccer. Methods: Data analyses were performed considering match physical performance of 120 team data (1200 player cases) of randomly selected Spanish, German and English first division championship matches (2013-14 season). Match analysis was performed with a validated semi-automated multi-camera system operating at 25 Hz. Results: During a match players covered 10673±348m of which 1778±208m and 2759±241m were performed at High-Intensity using the speed (≥16 km·h-1, HI) and metabolic power notations (≥20 watt·kg-1, MPHI). High-intensity notations were nearly perfect associated (r=0.93, p<0.0001). A huge method bias (980.63± 87.82m. d=11.67) was found when considering MPHI and HI. Very large correlations were found between match total distance covered and MPHI (r=0.84, p<0.0001) and HI (r=0.74, p<0.0001). Players high-intensity decelerations (≥-2 m·s2) coverage was very largely associated with MPHI (r=0.73, p<0.0001). Conclusions: The results of this study showed that the speed and MP methods are highly interchangeable at relative (magnitude rank) but not absolute (measure magnitude) level. The two physical match analysis methods can be independently used to track match external-load in elite level players. However match-analyst decisions must be based on single method use in order to avoid bias in external-load determination.
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The aims of this study were (i) to characterise the acceleration demands of two different formats of small-sided game (SSG), i.e., 4v4 + goalkeepers (4v4 + GK) and 8v8 + goalkeepers (8v8 + GK); (ii) to analyse the correlation between performance in power-based tests and acceleration-based physical loading during the two different SSG formats and (iii) to analyse the neuromuscular-induced fatigue. Eighteen adult male footballers participated in the study (20.7 ± 1.0 years, 178 ± 5 cm and 71.4 ± 2.1 kg). Baseline measurements were obtained from countermovement jumps, 15 s repeated jumps and 5 and 15 m sprints. A total of 36 min was analysed for each SSG (4v4 + GK: two sets of 3 × 6 min, and 8v8 + GK: 2 × 18 min). Heart rate, blood lactate, perceived exertion and movement pattern (GPS) were analysed. Distances covered by very-high-intensity activities and very-high-speed running were lower in 4v4 + GK than in 8v8 + GK (effect sizes (ES) = -0.69 ± 0.67 and -1.04 ± 0.67, respectively; very likely), while accelerations and decelerations were higher in 4v4 + GK than in 8v8 + GK (ES = 1.13-1.52; almost certainly). Blood lactate concentrations were higher (ES = 1.40 ± 0.58; almost certainly) and players perceived themselves to be more tired (ES = 0.80-2.31; almost certainly) after 4v4 + GK than after 8v8 + GK. Sprint ability in 5 and 15 m tests decreased (ES = 0.87 ± 0.58 and 0.89 ± 0.58, respectively; almost certainly) only after 4v4 + GK. This SSG format appeared more demanding in relation to repetitions and fatigue development of muscle power-based actions than 8v8 + GK. It may therefore be logical to use the former type of SSG to target development of power-related football actions.
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The aim of this study was to investigate the effects of 22 weeks of periodized training, with an emphasis on technical-tactical ability, on indirect markers of muscle damage and the on-field performance of young soccer players. Fifteen players (age 15.4 ± 0.2 years, height 172.8 ± 3.6 cm; body mass 61.9 ± 2.9 kg; % fat 11.7 ± 1.6; VO2max 48.67 ± 3.24 underwent four stages of evaluation: pre-preparatory stage - T0; post-preparatory stage - T1; post-competitive stage I - T2 and; post-competitive stage II - T3. The plasmatic activity of creatine kinase (CK) and lactate dehydrogenase (LDH) were evaluated as well as the on-field performance (movement patterns, tactical variables). Regarding the plasmatic activity of CK and LDH, there was a significant reduction (p ≤ 0.05) throughout the periodization training (T0: ~ 350 U/L; T3: ~ 150 U/L). Significant increases were observed (p ≤ 0.05) in the intensity of the game, high intensity activities (T0: ~ 22 %; T3: ~ 27%), maximum speed (T0: ~ 30 km.h; T3: ~ 34 km.h) and tactical performance, team surface area (T0: ~ 515 m; T3: ~ 683 m) and spread (T0: ~ 130 m; T3: ~ 148 m). In addition, we found significant inverse correlations between the percentage variation of T0 to T3 in CK and LDH activities with percentage variation in high intensity running (r = -0.85; p < 0.05 and r = -0.84; p < 0.01 respectively) and high intensity activities (r = -0.71 and r = -0.70; p < 0.05 respectively) during the matches. We concluded that there was reduced activity in biochemical markers related to muscle damage, as well as increases in-game high-intensity performance and the tactical performance of the study participants. Furthermore, players who showed greater reduction in plasma activity of CK and LDH also obtained greater increases in-game high-intensity performance along the periodization. These results may contribute to the expansion and future consolidation of the knowledge of coaches and sport scientists to develop effective methodologies for training in soccer.
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Lactate threshold (LT) represents the inflection point of blood lactate values from rest to high-intensity exercise during an incremental test, is commonly used to determine exercise intensity, and is related to different positional roles of elite soccer players. Different methodologies have been adopted to determine the LT, however, the agreement between these methodologies in pro-fessional soccer players is unclear. Seventeen professional soccer players were recruited (age 24.7 ± 3.7 years, body mass 70.1 ± 5.3 kg, height 172.8 ± 7.3 cm) and performed an incremental treadmill test until volitional fatigue. Speed at LT, heart rate at LT, and lactate values from capil-lary blood samples obtained at 3-min intervals were analyzed using four LT measurement meth-ods: visual inspection (VI), maximum distance (Dmax), modified Dmax (DmaxM), and loga-rithmic (log-log). Only Bland-Altman analysis for heart rate at LT showed agreement between VI and Dmax, between VI and DmaxM, and between Dmax and DmaxM methods. No agreement between methods was observed after ICC and 95% one-sided lower-limit analysis. Comparative results showed that speed at LT was lower (p<0.01) with the log-log method compared to the Dmax method, and lower (p<0.01) with the latter compared to the VI, and DmaxM methods. Re-garding heart rate at LT, higher (p<0.01) values were observed using the VI, DmaxM, and Dmax methods compared to the log-log method. Therefore VI, Dmax, DmaxM, and log–log methods should not be used interchangeably for LT measurement. More studies are needed to determine a gold standard for LT detection in professional soccer players.