Rev Bras Fisiol Exerc 2021;20(3):358-66
doi: 10.33233/rbfex.v20i3.4334
ORIGINAL ARTICLE
Effects of small-sided games on oxygen consumption,
agility, and focused attention in football
Efeitos
dos jogos reduzidos no consumo de oxigênio, agilidade e atenção concentrada no
futebol
Alexandre
de Souza e Silva1, José Jonas de Oliveira1, Guilherme Pascoal Mereu1, Victor
Hugo de Siqueira Montalvão1, Ronaldo Júlio Baganha1,
Fábio Vieira Lacerda1, Jasiele Aparecida
de Oliveira Silva1
1Centro
Universitário de Itajubá, Itajubá Teaching and Research Foundation (FEPI), Itajubá, MG, Brazil
Received: August 12, 2020; Accepted on: February 1,
2021.
Correspondence: Alexandre de Souza e Silva, Av. Dr. Antônio Braga Filho,
687 Varginha 37501-002 Itajubá MG
Alexandre de Souza e Silva: alexprofms@yahoo.com.br
José Jonas de Oliveira: joliveira63@gmail.com
Guilherme Pascoal Mereu:
guilherme.mereu@hotmail.com
Victor Hugo de Siqueira Montalvão: vdsiqueiramontalvao@yahoo.com.br
Ronaldo Júlio Baganha: ronaldobaganha@yahoo.com.br
Fábio Vieira Lacerda: doc_fabio2004@yahoo.com.br
Jasiele Aparecida de Oliveira
Silva: jasiele_oliveira@yahoo.com.br
Abstract
Introduction: The study
aimed to analyze the effects of training with games on reduced fields on the
maximum oxygen consumption, agility, and focused attention in soccer players. Methods:
For primary and quantitative research, the sample consisted of 10 male
athletes, 16.4 ± 1.5 years old, from a field soccer team. Maximum oxygen uptake
was obtained through the Cooper 12-minute run test. To measure agility, the
test Little and Williams was used, and to assess the concentrated attention,
the Concentrated Attention (CA) test was adopted. The small-sided game training
program lasted 12 weeks. The tests were carried out in the first and last week
of the research. The level of significance established for all situations was p
< 0.05. Results: There was an improvement in oxygen consumption (p =
0.012), in agility with ball (p = 0.0001), in agility without ball (p = 0.003),
and in concentrated attention (p < 0.001) after the small-sided game
training program. Conclusion: Training with small-sided games can
positively influence maximum oxygen consumption, agility, and focused
attention.
Keywords: soccer; exercise; endurance
training; physical fitness; attention.
Resumo
Introdução: O objetivo do estudo foi analisar os
efeitos do treinamento com jogos em campos reduzidos no consumo máximo de
oxigênio, agilidade e atenção concentrada em jogadores de futebol. Métodos:
Para a pesquisa primária e quantitativa, a amostra foi constituída de 10
atletas do gênero masculino, com idade média de 16,4 ± 1,5 anos de uma equipe
de futebol de campo. O consumo máximo de oxigênio foi obtido por meio do teste
de 12 minutos de Cooper. Para mensurar a agilidade, usou-se o teste de Little e
Williams e a atenção concentrada foi avaliada por meio do teste de Atenção
Concentrada (AC). O programa de treinamento de jogos reduzidos teve a duração
de 12 semanas. Os testes foram realizados na primeira e na última semana da
pesquisa. O nível de significância estabelecido para todas as situações foi de
p < 0,05. Resultados: Observou-se uma melhora no consumo de oxigênio
(p = 0,012), na agilidade com bola (p = 0,0001) e na agilidade sem bola (p =
0,003) e na atenção concentrada (p < 0,001) após o programa de treinamento
de jogos reduzidos. Conclusão: O treinamento com jogos reduzidos pode
influenciar positivamente no consumo máximo de oxigênio, na agilidade e na
atenção concentrada.
Palavras-chave: futebol; exercício físico; treino
aeróbico; aptidão física; atenção.
Football is a
sport that requires interaction between motor, technical, tactical,
physiological, and psychological factors [1]. This interrelation of dependency
that involves these factors requires means and training methods that work with
these variables both in isolation and in combination [2].
Thus, to meet
the demand imposed by high-level football, new training methodologies have been
used in the teams' daily lives [3]. Among the various methodologies, we
highlight the small-sided games, which simulate real game situations in reduced
dimensions of the field or with a reduced number of players, which means that
all variables related to the sport can be evaluated and subsequently improved
[4,5].
The small-sided
games improve the aerobic conditioning of the athletes since the reduced field
dimensions generate a physical overload, which results in positive adaptations
in the maximum oxygen consumption [4]. As it is an unpredictable sport,
football also requires some specific variables, such as, for example, agility
[6]. The constant changes of directions, accelerations, and decelerations
existing during a game, make the coaches seek to work agility in an isolated
way so that they can carry out the movements naturally and with greater efficiency
during the game [7]. It is also suggested that small-sided games in numerical
inferiority can improve concentrated attention. However, few studies analyze
attention concentrated in small-sided games in numerical equality [8].
Therefore, what makes this research relevant is the scarcity of studies
relating small-sided games in numerical equality to maximum oxygen consumption,
agility, and attention focused on football. Thus, the objective of this study
was to analyze the effects of the game training program in small fields in a
situation of numerical equality in the maximum oxygen consumption, agility, and
attention focused on soccer players.
Type of research and sample characterization
The research is
primary, longitudinal, and quantitative. The sample consisted of 10 athletes
who regularly attended training and were submitted to game sessions in small
fields during the preparatory period. All research subjects were male from a
team in the south of Minas Gerais, Brazil, between 15 and 20 years old. The
inclusion criteria were athletes playing football for at least 3 years and
trained for 3 to 4 days a week for at least 1 hour a day. Exclusion criteria
were individuals with history of musculoskeletal injury in the last 6 months.
The groups were divided into two training sessions of reduced games, 5 vs. 5 in
numerical equality, alternating the offensive with the defensive.
Participants
were informed about the risks, benefits and invited to participate in the
research. All those involved signed the Free and Informed Consent Term, with
details about all the research procedures. This study meets international
standards for experimentation with humans. The project was submitted for
appreciation and approved by the Research Ethics Committee of the Centro Universitário de Itajubá/Brazil,
according to protocol 370.978.
Instruments
To assess body
mass and height, a Welmy® scale (Brazil) with a
capacity of up to 180 kg and fractions of 100 g was used, with a stadiometer attached
[9].
To obtain the
heart rate during games in a reduced field, a Polar Electro Oy®
cardio-frequency meter, Vantage, Finland [10], was used. Maximum oxygen
consumption was measured using the Cooper 12-minute run test performed on a
flat track [10,11]. Agility was assessed using the agility test adapted from
Little and Williams [12,13].
The concentrated
attention test is an instrument that aims to assess the ability to keep
attention focused on the activity performed under time pressure. The instrument
is approved by the Federal Council of Psychology and consists of 21 lines, each
with 21 different stimuli. The subject's task is to locate stimuli equal to the
three stimuli presented in a model frame. It can be applied individually or
collectively [14].
Procedures
To assess body
mass and height, athletes had light clothes and were without shoes. To
calculate the Body Mass Index (BMI), the formula: weight/height² (kg/m2) [9,15]
was used.
To control the
intensity during games on a reduced field, heart rate data (80-95% HRmax) [16]
were used according to the formula: 208 - (07 x age) [17] collected during the
3 training sessions weekly 40-minute sessions in each session for 12 weeks.
In the Cooper
12-minute run test, the subjects covered a 400 m flat track with markings every
50 m, during 12 minutes without interruptions, with a record of the total
distance covered in that time interval [10,11]. Agility was obtained by the
agility test adapted from Little and Williams, which agility is given by the
time athletes spend to cover a distance of 20 m, with
successive changes of direction every 4 meters, with and without a ball. Two
tests were performed, with the shortest time recorded between them [12,13].
The application time
of the concentrated attention test was 5 minutes, with attention and cognitive
and mental control being evaluated in pressure situations [14].
The athletes
were randomly assigned to two groups. In the first moment, the training of 5
vs. 5 players was performed in a numerical equality situation, and in the
second moment, the players were alternated in the offensive and defensive
situations. The sessions were divided into two stages, each lasting 7 minutes,
with a 5-minute recovery interval between them, with the field dimensions used
being 10 m x 20 m.
Sample size
The sample was
calculated using GPower version 3.1.9.2 (Universität
Kiel, Germany). The estimate was based on data from the concentrated attention
of the first 6 volunteers (Cohen's d = 0.86). It was indicated that 10
individuals were needed for a power of 80% (1-?), an alpha value of 0.05
(two-tailed), and an allocation ratio of 1.
Statistical analysis
During the
research course, we sought to verify whether the small-sided game training
program influenced variables, such as maximum oxygen consumption, agility, and
focused attention. The data were analyzed quantitatively, through the
descriptions of the mean and standard deviation, in addition to the
verification of normality by the Shapiro-Wilk test and the symmetry of the data
(through the histogram). After the preliminary analysis, it was found that the
data are parametric. Thus, the paired Student's t-test was used to verify
whether there is a difference between the means.
The percentage
variation was calculated between the pre- and post-training program (D%). Cohen's formula was used to calculate the effect
size [18], and the magnitude threshold was ≤ 0.19 trivial; between
0.20-0.59 small; between 0.60-1.19 moderate; between 1.20-1.99 large; and ≥
2.00 very large.
Statistical
analysis was performed using the Statistical Package for the Social Sciences
(SPSS) version 20.0® for Windows (Chicago, IL. USA), and the significance level
adopted for all situations was p < 0.05.
Table I shows
the characteristics of the athletes. The data are described in means and
standard deviation (SD).
Table I - Sample
characterization
It was observed
that the training method significantly influenced the increase in maximum
oxygen consumption after the training program, as described in figure 1.
*Significant difference
(p = 0.012) compared to the assessment before (mean ± SD = 37.79 ± 7.28 and
after (mean ± SD = 39.16 ± 6.94) of the training period, (effect size = - 0.19
- trivial) and (D% = 3.62); VO2max = maximum oxygen consumption
Figure 1 - Effects
of small-sided game training programs on maximum oxygen consumption
The results of
agility are shown in figure 2 and figure 3. The small-sided game training
program also improved agility with and without a ball in soccer players.
*Significant difference
(p < 0.001) compared to the assessment before (mean ± SD = 14.50 ± 0.81 and
after (mean ± SD = 13.38 ± 0.32) of the training period, (effect size = 1.81 -
large) and (D% = -7.72)
Figure 2 - Effects
of small-sided game training programs on ball agility
*Significant difference
(p = 0.0003) in comparison to the evaluation before (mean ± SD = 7.00 ± 0.26)
and after (mean ± SD = 6.63 ± 0.29) of the training period, (effect size = 1.34
- large) and (D% = -5.28)
Figure 3 - Effects
of small-sided game training programs on agility without a ball
After the
small-sided game training program, as described in figure 4, it is observed
that the Concentrated Attention Test also showed a significant difference
between pre- and post-evaluation.
*Significant difference
(P < 0.001) compared to the assessment before (mean ± SD = 74.50 ± 17.36)
and after (mean ± SD = 87.50 ± 18.61) of the training period, (effect size =
-0.72 - moderate) and (D% = 17.44); Percentage (mean before
= 50.67 ± 11.81; mean after 59.51 ± 12.66)
Figure 4 - Effects
of small-sided game training programs on the Concentrated Attention Test
The study aimed
to analyze the influence of the game training program in reduced fields in a
situation of numerical equality in the maximum oxygen consumption, agility, and
focused attention in soccer athletes. The study's main findings indicate that
maximum oxygen consumption, agility with and without a ball, and focused attention
increased significantly after the training program.
The result
regarding the maximum oxygen consumption in the present study corroborates the
results found in the literature. According to Owen et al. [19], four
weeks of training with small-sided games in elite soccer athletes promoted an
enhancement in maximum oxygen consumption. The training sessions lasted from 45
to 90 minutes, in a 30 x 25 m area, with 3-line players and the goalkeeper in
each team. Other studies also confirm that the maximum oxygen consumption shows
improvement after training in games with reduced field [3,11]. High-intensity
interval training is a feature of small-sided games that can improve VO2max
consumption. Peroxisome proliferator-activated receptor gamma coactivator
1-alpha (PGC-1α) is a protein that contributes to increased mitochondrial
density, which makes it an essential organ of aerobic metabolism.
High-intensity training stimulates the synthesis of PGC-1α, which may
explain the improvement in aerobic conditioning through reduced games [20,21].
Also, it was
evidenced in the present study that the reduced field games significantly
improved the athletes' agility. The results obtained in the research coincide
with the data available in the literature. It is believed that training with
small-sided games has been quite efficient in improving athletes' agility, as
it is a training method that requires constant changes of direction, in
addition to successive accelerations and decelerations [22]. According to Davies
et al. [23], the reduced field games with increased density (5 vs. 5)
generate better agility responses performed by the player. A possible
explanation for this effect is the combination of more agility events occur in
situations of attack, defense, and without possession of the ball. In this
sense, it is suggested that a greater demand for agility be imposed on players
due to the reduced and dense spaces, which forces players to consider the
relative position adopted by the other opponents within the reduced field
space, even before making decisions to move, with or without a ball.
Finally, the
focused attention showed a significant difference after the reduced field game
training program in numerical equality. The results obtained in the study corroborate
the data available in the literature. In the study by Montalvão
et al. [8], the training program reduced in numerical inferiority showed
a significant difference when comparing a smaller number of players to the
collective. Thus, the smaller the number of athletes, the higher the focus on
activity and attention, in addition to higher cognitive and mental control in
high-pressure situations. According to Ribeiro et al. [24], the
incidence of goals is higher at the end of the match, and players may experience
decreased concentration due to fatigue.
The study
presented a limitation regarding the sample number. Despite meeting the minimum
suggested by the sample calculation test, a higher number of volunteers would
further strengthen the results, and this limitation can be due to the
difficulty of maintaining the volunteers, especially in longitudinal studies.
In terms of
practical applications, the present study offers another alternative to
physical trainers and soccer coaches since they can physically and technically
condition athletes and simultaneously optimize training time.
It is concluded
that the training of small-sided games in a numerical equality situation of 5
vs. 5 players significantly improves maximum oxygen consumption and athletes'
agility, as well as focused attention. It is suggested for further studies, the
maintenance of the current dimensions of the field and the work in inferiority
and numerical superiority, as well as the use of more complex methodologies and
larger sample size.
Potential conflict of
interest
No conflicts of
interest with a relevant potential to this article have been reported.
Financing source
Minas Gerais Research
Funding Foundation - FAPEMIG
Academic affiliation
There is no affiliation
between this study and graduate programs.
Authors' contributions
Conception and design
of the research: Silva AS, Mereu GP, Oliveira JJ, Montalvão VHS, Silva JAO. Obtaining data: Mereu GP, Montalvão VHS. Analysis
and interpretation of data: Silva AS, Mereu GP, Baganha RJ, Silva JAO. Statistical analysis: Silva AS, Mereu GP. Obtaining financing: Silva AS, Mereu GP, Montalvão VHS, Lacerda FV. Writing of the paper: Silva AS, Mereu GP, Oliveira JJ, Lacerda
FV, Silva JAO. Critical review of the paper for important intellectual content:
Silva AS, Oliveira JJ, Baganha RJ, Lacerda FV, Silva JAO.