EQOL Journal (2023) 15(1): 19-26
ORIGINAL ARTICLE
19
The influence of linear speed on the ability to change the direction of
movement in elite female football players
Dejan Javorac
1
✉ • Aleksandar Vrbaški
1
• Saša Marković
2
•
Slavko Molnar
1
Received: 10
th
April, 2023 DOI: 10.31382/eqol.230603
Accepted: 9
th
May, 2023
© The Author(s) 2023. This article is published with open access.
Abstract
The aim of this study was to show the influence of
linear speed on the ability to change the direction of
movement. Nineteen football players (16.90±2.28
years old) from the Serbian Super League
participated in the research. Tests were performed to
estimate speed: the linear speed at 5 m, 10 m, 20 m,
and flying start at 10 m, and the 505 test for
dominant and non-dominant leg, as well as CODS
deficit, were applied to assess the ability to change
direction. Using regression analysis, it was shown
that linear speed has no statistically significant
effect on the ability to change direction with elite
female football players (P<0.05). In interpreting the
results, several factors should be taken into account
and the complexity of the linear speed relationship
and the ability to change direction should be
understood. The findings we gained from this
research could influence the modification of training
cycles, primarily strength, movement mechanics,
and later more specific training episodes of football
players.
Keywords speed • female football players • ability
to change the direction of movement.
Introduction
Football is a game that is actively played by over
240 million people in more than 200 countries of
the world. The continuous growth and popularity
of the game itself are reflected in the increasing
number of football clubs as well as active players
not only in the men's but also in the women's
competition. The requirements of today's football,
viewed from the point of view of physical
qualities, are certainly different compared to the
very beginnings of this sport. Fitness aspects,
especially those related to high-intensity activities,
have changed a lot over the past years (Bradley et
al., 2015). Moreover, it was shown that male
players had better COD performance and more
excellent sprint mechanical properties than female
football players (Zhang et al., 2021).
Speed and the ability to change the direction of
movement are very important factors in football,
their development starts from childhood and
determines the performance of football players
(Kyranoudis et al., 2021). Accordingly, change of
direction (COD) is the ability to change the
direction of movement and can be a good predictor
of success given a large number of changes of
direction of movement (more than 700 in men
during a football game) that are performed in one
football match (Bloomfield et al., 2007). On the
other hand, speed is also important for success in
football. Most high-intensity activities (sprints and
accelerations) occur during decisive moments,
such as scrambles for the ball, offensive and
defensive actions, and scoring opportunities (Di
Salvo et al., 2009).
✉
javorac.dejan@gmail.com
1
University of Novi Sad, Faculty of Sport and
Physical Education, Novi Sad, Serbia
2
University of Banja Luka, Faculty of Physical
Education and Sport, Banja Luka, Bosnia and
Herzegovina
EQOL Journal (2023) 15(1): 19-26
20
Many identify agility with the ability to COD of
movement; however, agility is defined as the ability
to quickly change the direction of motion, noting that
there is an external stimulus, and changing the
direction of movement, or COD, is one of the
components of agility, which includes technique, the
explosiveness of the lower extremities, as well as the
ability to effectively brake and accelerate (Javorac,
2017; Sheppard, & Young, 2006).
Linear accelerations and sprints are the most
common actions performed by a football player
before the actual act of scoring a goal, and this applies
not only to the scorer but also to the assistant (Haugen
et al., 2013). The terms acceleration and sprints are
used in many speed development programs, but it is
necessary to distinguish between these two terms.
Acceleration represents the rate of increase in speed,
and sprinting is the highest rate of speed an individual
reaches (Jeffreys, 2013). Because of this, running at
maximum speed at distances of 5 or 10 meters cannot
be called sprints because maximum speed is not
reached. From that aspect, we can define speed as the
ability to accelerate and reach top speed (Haff &
Triplett, 2013).
Studies over several decades show that soccer
players become faster over time (Haugen et al., 2013;
Tønnessen et al., 2013) and it is interesting to see if
increasing speed affects the ability to COD
movement. The fact that in the English Premier
League, in a period of 10 years, the number of high-
intensity activities increased by as much as 50 percent
(Fransson et al., 2017) tells us how important speed is
for football in general. It is clear to us that the ability
to COD movement plays a big role in these activities,
because football is not only about straight
movements.
The topic of this research is precisely two
anaerobic components that significantly impact
football performance. For running speed, we can say
that it represents the ability to accelerate and reach
maximum speed (Haff & Triplett, 2013). It is related
to the ratio of step length and frequency, which means
that by increasing either of these two variables, we
also affect the increase in speed itself. The ability to
COD movement represents exactly that, the ability to
quickly change the direction of movement but
without the influence of an external stimulus and
during pre-planned activities.
There is a certain amount of research directly or
indirectly related to the topic; however, the vast
majority only included work with the male
population. A small share of research has dealt with
this topic among female soccer players. For example,
Lockie et al. (2018) conducted research on female
players of Division I and Division II of the American
National College Association and showed that there
is a significant statistical correlation between the
linear speed at 10 meters and the ability to COD
movement, the parameter of which was taken as test
505. Similar results were shown with soccer players
(Loturco et al., 2018). However, there are many
studies on soccer players where there is no
statistically significant influence of speed on the
ability to COD (Freitas et al., 2021; Papla et al., 2020;
Sammoud et al., 2021). In other sports, there is a
noticeable difference in the results obtained, both for
men (Buchheit et al., 2012; Suarez-Arrones et al.,
2020) and women (Nimphius et al., 2010).
According to all the previously mentioned
research, we can see that the data are undoubtedly
contradictory, considering that a large number of
studies prove the influence of linear speed on the
ability to change the direction of movement, 'which
deny it. This is precisely why the research aims to see
how much the linear speed affects COD in these
conditions.
Method
This research was carried out on the sports fields in
Novi Sad. The testing was carried out under the
guidance of professional staff from the Faculty of
Sports and Physical Education in Novi Sad. Modern
equipment was used, photocells (Microgate,
Polifemo Radio Light, Bolzano, Italy), with an
accuracy of 0.001 s. In the preparation of the work,
the available scientific literature, as well as primary
and secondary sources, were used. The conducted
study is by the ethical standards of the Declaration of
Helsinki.
Nineteen football players of different ages from
the women's football club in the Serbian Super
League (16.90±2.28 years) participated in the testing.
In order to participate in the research, the respondents
needed proof of a completed medical examination,
where their physical readiness for the efforts required
by sports activities was confirmed. In addition, the
subjects were informed verbally and in writing about
the protocol, potential risks, and benefits of the study.
Also, they were required to provide written consent to
participate in the research.
To evaluate the speed, the following parameters
were taken into consideration:
EQOL Journal (2023) 15(1): 19-26
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1) Linear speed at 5 meters
2) Linear speed at 10 meters
3) Linear speed at 20 meters
4) Flying sprint 10 meters
To assess the ability to COD movement, the
following was taken into consideration:
1) 505 test for dominant and non-dominant leg
2) COD deficit
The football players were familiar with the complete
testing procedure. Their tasks were demonstrated and
explained in detail, while the measurers had previous
training so that the obtained data would be as valid as
possible. Before the tests themselves, the test subjects
performed a dynamic warm-up to raise their body
temperature and reduce the risk of injury to a
minimum. After the dynamic warm-up, a protocol
consisted of acceleration, jumping, and braking as
adequate preparation for the test. Each linear run was
done twice, and a better result was taken for all
variables. The 505 test was performed twice per leg.
The designed initially 505 test was made so that we
could measure “agility” in the horizontal plane
(Draper et al., 1985). Considering that the test
subject's activity is planned, this test is suitable for
assessing the ability to COD movement.
Test 505, they started with maximum acceleration
to the line 15 m away, turned 180° so that their right
leg is the one that pushes off when changing the
direction of movement, and then passed through the
gate 5 m away at maximum speed. Female athletes
are not allowed to touch the floor with their hands and
not to use the hand push-off during the turn. After 3
minutes, the test was repeated with the other leg.
Some findings tell us that the 505 test is valid and
reliable for evaluating the change in the direction of
movement (Stewart et al., 2012).
For the linear speed tests, the gates were placed at
5, 10, and 20 meters from the start and 20 and 30
meters for the 10 m flying sprint. Their task was to
run the given distance in the shortest period, and for
each test, they had two attempts with a 3-minute
break in between. A better result was taken for the
analysis.
Testing was done on an open field with an
artificial grass surface in the morning hours (9:00-
11:00), during favorable weather conditions (no wind
or rain). On the first day, the linear speed at 5 and 20
meters as well as the flying sprint at 10 were tested,
and the second day was scheduled for the linear speed
at 10 meters and the 505 test.
The data were processed using the Statistical
Package for Social Science, version 21.0 (SPSS Inc.,
Chicago, Illinois, USA). Regression analysis was
applied in order to see the influence of speed on the
ability to change the direction of movement as well as
the COD deficit. The level of statistical significance
was set as P<0.05.
Results
Data processing to determine the influence of linear
speed on the ability to change the direction of
movement was performed using multiple linear
regression. A review of the Normal Probability plot
diagram proves that the results do not deviate from
normality. Tabachnick and Fidell (2007) define non-
peak points as cases with a standardized residual
greater than 3.3 or less than -3.3. Tolerance and VIF
(Variance inflation factor) values indicate that the
assumption of the non-existence of multicollinearity
is not violated.
Regression analysis was applied to see the effect of
speed on time required to perform the 505 test with
the dominant leg. The coefficient of determination is
0.219; based on it, we conclude that our model
describes 21.9% of the total variance. The
significance of the model is 0.449, which means that
the model is not significant. Therefore, based on the
previous variables, we cannot predict the time for test
505 with the dominant leg.
EQOL Journal (2023) 15(1): 19-26
22
Table 1. Presentation of the linear speed regression analysis for the 505 test with the dominant leg
B
Standard Error
Standardized Beta
Sig.
-0.243
1.059
-0.108
0.822
0.184
0.657
0.122
0.784
-0.092
0.838
-0.097
0.914
1.007
1.152
0.519
0.397
Note: R
2
=0.21
Although the highest correlation was obtained
between the speed of the flying sprint at 10m and the
ability to COD movement measured by the 505 test
for the dominant leg (Table 1), no variable has a
significant contribution to the obtained model, that is,
no variable influences the ability to COD movement
measured by the 505 test for the dominant leg foot.
Regression analysis was also applied to see the effect
of speed on time required to perform the 505 test with
the non-dominant leg. The coefficient of
determination is 0.180, and based on it, and we
conclude that our model describes 18% of the total
variance. Therefore, the significance of the model is
0.563, which means that the model is not significant;
that is, we cannot predict the time for test 505 with
the non-dominant leg based on the previous variables.
Table 2. Presentation of the linear speed regression analysis for the 505 test with the non-dominant leg
B
Standard Error
Standardized Beta
Sig.
-1.098
0.908
-0.585
0.246
0.176
0.563
0.140
0.759
0.401
0.718
0.506
0.585
0.148
0.987
0.091
0.883
Note: R
2
=0.180
Although the highest correlation was obtained
between the speed at 5m and the ability to COD
movement measured by the test 505 for the non-
dominant leg (Table 2), none of the variables has a
significant contribution to the obtained model that is,
none of the variables influences the ability to COD
movement measured by the test 505 with the non-
dominant leg.
Regression analysis was applied a third time to see
speed's influence on the COD deficit. The coefficient
of determination is 0.213, and based on it, and we
conclude that our model describes 21.3% of the total
variance. The significance of the model is 0.466,
which means that the model is not significant; that is,
we cannot predict the time for test 505 with the non-
dominant leg based on the previous variables.
Table 3. Presentation of the linear speed regression analysis for the COD deficit test
B
Standard Error
Standardized Beta
Sig.
-0.243
1.059
-0.109
0.822
-0.816
0.657
-0.546
0.234
-0.092
0.838
-0.098
0.914
1.007
1.152
0.521
0.397
Note: R
2
=0.213
Although the highest correlation was obtained
between the speed at 10m and the COD deficit, (Table
3), none of the variables has a statistically significant
contribution to the obtained model; that is, none of the
variables has an impact on the COD deficit.
Discussion
The research aimed to determine the influence of
linear speed on the ability to change the direction of
movement.
EQOL Journal (2023) 15(1): 19-26
23
For linear speed parameters, four variables were
taken into account: the linear speed at 5 meters, the
linear speed at 10 meters, the linear speed at 20
meters, and the flying sprint at 10 meters. For the
parameters of the ability to change the direction of
movement, three variables obtained based on the
performance of test 505 were taken into
consideration, namely: the time required to perform
the test with the dominant leg, the time required to
perform the test with the non-dominant leg and the
COD deficit (parameter obtained by from the time
required to perform the 505 test subtract the time
required to perform the linear velocity test at 10
meters).
Based on the data obtained using regression
analysis, it was determined that linear speed has no
statistically significant influence on the ability to
change the direction of movement and the COD
deficit.
The results of this study confirm the earlier
conclusion that linear speed and the ability to change
the direction of movement are two separate physical
components (Javorac, 2017; Sheppard & Young,
2006; Suarez-Arrones et al., 2020). Therefore, we
define the ability to change the direction of movement
as the physical capacity of an athlete to change the
direction of movement while simultaneously slowing
down and immediately after that accelerating
movement using different forms of movement. In
contrast, we define speed as the ability to accelerate
and reach maximum speed.
The reason for the fact that these are two different
components could lie in the fact that at high speeds,
we need much more significant force to decelerate,
i.e., to freeze effectively (Buccheit et al., 2012).
Therefore, we conclude that a person who can achieve
a higher speed must also exert a tremendous effort to
achieve an efficient change of direction. COD is a
very complex ability, and it depends on many factors
such as power, movement mechanics, braking and
acceleration, and the entire kinematic component.
Locke et al. (2018) conducted a study that supports
these findings in football players with similar tests. A
study from last year with pre-adolescent football
players that took into account the 505 test as well as
tests for the assessment of linear speed at 5, 10, and
20 meters also did not show a significant effect of
speed on the change of direction of movement but
also on the COD deficit (Sammoud et al., 2021), as
well as a very similar study from the same year
(Freitas et al., 2021). Research conducted on
professional football players of the Polish second
league showed no statistically significant relationship
between the linear speed at 20 meters and COD
deficit for both legs (Papla et al., 2020).
On the other hand, one study investigated a similar
topic by measuring the effect of flying sprints on
COD ability as measured by the zig-zag test, and the
results obtained also show a statistically significant
association between flying sprints at 20 and 10 meters
and change of direction in youth soccer players
(Loturco et al., 2018).
In addition to these, some studies were conducted
on something other than football players. First, the
research on netball players did not show a statistically
significant correlation between the speed at 10 meters
and the time obtained on the 505 test for both the
dominant and the non-dominant leg. In the same
research, data showed a statistically significant
inverse relationship between 10-meter linear sprint
and COD deficit, which further implies that faster
athletes have a more significant COD deficit
(Dos'Santos et al., 2019).
One study on non-athletes found a significant
association between the change of direction and linear
sprints of 10 and 20 meters. This study explains the
high correlation with the fact that the tests for
changing the direction of movement were more
extended than 20m (30-40m). They believe that the
distance run and the number of turns the individual
needs to make significantly influence the correlation
results (Suarez-Arrones et al., 2020). Research on 12
individuals coming from team sports showed a
considerable statistically significant influence of
linear speed on the ability to change the direction of
movement at an angle of 45°. This research also
points out that by increasing the angle of change of
direction of movement, linear speed has less and less
influence, and this is supported by the opinion that
when changing direction at an ang