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Scand J Med Sci Sports. 2024;34:e14646.
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https://doi.org/10.1111/sms.14646
wileyonlinelibrary.com/journal/sms
Received: 22 January 2024
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Revised: 22 March 2024
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Accepted: 22 April 2024
DOI: 10.1111/sms.14646
ORIGINAL ARTICLE
Impact of temperature on physical and cognitive
performance in elite female football players during
intermittent exercise
AlbertoPompeo1
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JoséAfonso2
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Everton Luis RodriguesCirillo1,3
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Júlio A.Costa4
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JoséVilaça- Alves5,6
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NunoGarrido5,6
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SixtoGonzález- Víllora7
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Andrew MarkWilliams8
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FilipeCasanova1
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any
medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2024 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
1Centro de Investigação em Desporto,
Educação Física, Exercício e Saúde
(CIDEFES), Lusófona University,
Lisbon, Portugal
2Centre for Research, Education,
Innovation and Intervention in Sport
(CIFI2D), Faculty of Sport of the
University of Porto, Porto, Portugal
3State University of Londrina (UEL)/
Sports Science Department, Londrina,
Brazil
4Portugal Football School, Portuguese
Football Federation, Oeiras, Portugal
5Department of Sport- Sciences,
Exercise and Health, University of Trás-
os- Montes and Alto Douro, Vila Real,
Portugal
6Research Center in Sports, Health, and
Human Development (CIDESD), Vila
Real, Portugal
7Sport and Physical Activity Education
Research Group, Faculty of Education,
University of Castilla- La Mancha,
Albacete, Spain
8Department of Healthspan, Resilience,
and Performance Group, Institute
for Human and Machine Cognition,
Pensacola, Florida, USA
Correspondence
Sixto González- Víllora, Sport and
Physical Activity Education Research
Group, Faculty of Education, University
of Castilla- La Mancha, Albacete, Spain.
Email: sixto.gonzalez@uclm.es
Abstract
There is limited research on female football players, especially related to their
physical and cognitive performance under different climactic conditions. We
analyzed the impact of a hot environmental temperature on physical perfor-
mance and anticipation in elite female football players during a fatigue- inducing
intermittent protocol. Elite female players (n = 21) performed the countermove-
ment jump (CMJ) and responded to filmed sequences of offensive play under two
distinct environmental temperatures (i.e., mild environment temperature- 20°C
and 30% rh versus hot environment temperature- 38°C and 80% rh), interspersed
by 1- week interval. Linear mixed models were used. CMJ performance declined
following the intermittent protocol on both temperature conditions (p < 0.05).
Moreover, there were significant main effects for protocol on CMJ speed (m/s)
(p = 0.001; ηp2 = 0.12), CMJ power (p = 0.002; ηp2 = 0.11), and CMJ Heightmax
(p = 0.002; ηp2 = 0.12). After performing the intermittent protocol, exposure to a
hot temperature caused a greater decline in anticipation accuracy (mild tempera-
ture = 64.41% vs. hot temperature = 53.44%; p < 0.001). Our study shows impaired
performance in elite female football players following an intermittent protocol
under hot compared with mild environmental conditions. We report decreased
performance in both CMJ and anticipation performance under hotter conditions.
The results reveal that exposure to hot temperatures had a negative effect on the
accuracy of their anticipatory behaviors. We consider the implication of the work
for research and training interventions.
KEYWORDS
anticipation, fatigue, hot environment, physical performance, soccer, women
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1
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INTRODUCTION
The importance of climate change and environmental
diversity on players physical1 and perceptual- cognitive2,3
performance is well- reported. For example, during the
2014 FIFA World the weather in Brazil became a major
concern for many football teams since, under thermal
stress, running and jumping abilities are compromised to
a greater extent than under temperate conditions.4 Several
international federations, including FIFA, responded to
the International Olympic Committee's call to create a sur-
veillance system to assess environmental conditions and
their adverse outcomes during competition.5 According
to Wet- Bulb Globe Temperature Risk Chart6 mild and
hot environment temperature conditions are classified
as 18°C–23°C and >28°C, respectively. Regardless, major
competitions continue to be scheduled in equatorial or
Middle Eastern regions (e.g., the 2022 Qatar Football
World Cup) that still present challenges in preventing in-
jury and illness in athletes. Also, as physical exhaustion
increases in adverse weather conditions, such conditions
may impact cognitive function including anticipation and
decision- making.7
Published reports highlight that extreme environmen-
tal conditions impact body homeostasis, promoting dehy-
dration, thermal stress, and affecting body temperature
and player performance.8,9 During exercise, behavioral
mechanisms may adjust and regulate according to envi-
ronmental conditions and through duration and/or inten-
sity.10 In addition, researchers have shown that exercise
performed at a hot environment temperature and high rel-
ative humidity (e.g., 35°C and 80%rh) causes the body to
produce more sweat to dissipate heat, increasing the body's
demand to maintain an adequate core temperature.11
These effects may impair cognitive performance, even
at moderate exercise intensities.12 Unsurprisingly, expo-
sure to a hot environmental temperature impairs soccer-
specific decision- making.2 Moreover, there have been some
attempts to study how anticipation is affected by increas-
ing physical and physiological demands.13 Physiological
workload and the tactical expertise of football players have
been shown to interact, impacting perceptual- cognitive
function (e.g., visual search behavior) in game situations.
The ability to recognize and anticipate what an opponent
will do next and to execute the most appropriate decision
are important components of performance in football.14
The ability of players to anticipate quickly and accurately
relies on the development of domain- specific perceptual-
cognitive skills that interact dynamically.3 It is not well-
reported how physical exhaustion3 and/or environmental
temperature2 impact on these cognitive functions.
The skilled performer's ability to cope with stressors,
such as fatigue and hot environment temperatures, could
determine how these skills are executed in extreme match
situations. It is well stablished that a hot environmental
temperature significantly influences physical and physio-
logical variables,15 dehydration levels, autonomic nervous
system assessed throughout heart rate variability (HRV)
indices,16 muscle strength loss and power,17 and decision
accuracy.2,18 In contrast, the exercise- cognition interac-
tion in high- demanding physiological and thermal en-
vironments has not been well- documented.2,3 Scientists
have proposed an inverted- U relationship between exer-
cise intensity and cognitive performance,19 with moder-
ate- and high- intensity exercise increasing and impairing
performance, respectively. Similarly, Attentional Control
Theory (ACT)20 was proposed to clarify how attentional
resources and subsequent performances are influenced
under increasing levels of stress during performers.
Mental fatigue can lead to further reductions in tactical
performance20 and it has been shown to impair technical
skill execution,21 both are important components of in-
termittent sports performance22,23 and key predictors of
success.24,25 These cognitive impairments have the poten-
tial to threaten the health and performance of athletes in
competition and increase the risk of injury,26 particularly
in a sport where complex tactical decision- making and
the technical execution of skills have a large influence on
match outcomes.27
Previous reports have highlighted methodological
shortcomings pertaining to measurement sensitivity,
poor research design, and lack of experimental control.28
Generally, studies conducted in laboratory environments
are more suitable for reliable assessment of player per-
formance under different temperature conditions, while
improving the safety of the participants,29 and helping the
research community to better understand the interaction
between laboratory and real- field contexts.30,31 Moreover,
some instruments, like cycle ergometers have been com-
monly used when field measures are unavailable, or for
the measurement of variables that are difficult to imple-
ment in the field (power, force, and speed profiling).32 In
this vein, an intermittent exercise protocol was validated
for football players, which reproduced the maximal physi-
cal effort during the match.33
Previous attempts to research this phenomenon in
football have mostly been limited to male players.34–37
Yet, researchers have shown that men and women pres-
ent different physiological responses to exercise under
hot environment temperatures,38,39 although it is unclear
to what extent these differences impact sports- specific
performance. Additionally, global warming and gender
equality have become priority areas on the United Nations
agenda.40 In this context, studies that evaluate the effects
of hot environments on female players are of great im-
portance for the football community, particularly given
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the notable absence of previous work on this topic.41
Although some attempts have been reported that evaluate
the effects of fatigue on the physical capacities of female
football players,42,43 and the effect of fatigue on the men-
tal capacities of the players,44 further efforts are needed to
evaluate the physical and cognitive performance of female
football players.
The present study was designed to assess the im-
pact of exposure to hot environmental temperatures
on the physical and perceptual- cognitive performance
of female football players using a laboratory- based in-
termittent protocol. This approach addresses a relevant
gap in the literature combining an intermittent exercise
protocol, realistic film- based simulations of offensive
sequences of play, and physical performance measures
of female football players under controlled temperature
conditions (i.e., mild environment temperature- 20°C
and 30% rh, and hot environment temperature- 38°C
and 80% rh). We assess physical performance using CMJ
(i.e., maximum height, strength, power, and speed),
and perceptual- cognitive performance using a soccer-
specific, film- based task that require players to anticipate
what will happen next. Based on previous research high-
lighting the detrimental effects of workload on physi-
cal2 performance and anticipation3 in male players, we
hypothesized that CMJ and anticipatory performance of
female players would decrease after an intermittent ex-
ercise protocol, regardless of the temperature exposure.
We expected a decline in the anticipatory performance
of female football players in response to hot environ-
ment temperature.
2
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MATERIALS AND METHODS
2.1
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Subjects
The G*Power version 3.1.9.7 was used to calculate sample
size and a minimum of 21 players were required (f2 = 0.91,
α = 0.05, and β = 0.95).45 A sample of 21 elite female foot-
ball players were recruited to participate. The participants
had all played professionally in the Portuguese Premier
League for at least two seasons, all of them played for their
national teams (Portugal and Brazil), and trained regu-
larly 5 ± 1 h sessions per week. Following the Participant
Classification Framework,46 the competitive level of our
participants corresponded to Tier 4 – Elite/International
Level. We collected anthropometric data before the pro-
tocol was initiated, such as height (Seca 213 portable sta-
diometer, Seca, Hamburg, Germany), body mass (BM),
body mass index (BMI), and the body fat (Omron Body
Composition Monitor BF511, Omron, Kyoto, Japan) (see
Table1).
All participants were informed by oral and written
communication about the experimental procedures. The
study was approved by the Ethics Committee of the lead
university (protocol number M25A21), and all procedures
were conducted in accordance with the Declaration of
Helsinki.
2.2
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Study measures
2.2.1
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Ambient temperature
To control the ambient temperature, we used a Cubicle
Tent (At- Home Cubicle Altitude Tent Standard 120 cm
height × 96 cm × 72 cm, Hypoxico Altitude Training
Systems, New York, USA), and two heaters to raise the
ambient temperature (Heater 1500 W, Hera Equation,
Madrid, Spain). The temperature and humidity inside
the tent were measured through the thermometer (C.A
895 hygrometry and environment, Chauvin Arnoux,
Normandy, France; Accuracy: ± 0.1% reading +1°C) and
a fan (VEN- SS- 21245 W, Sogo, Osaka, Japan).
2.2.2
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Heart rate
The exercise workloads were recorded using a heart rate
(HR) strap device, recorded in 5- s interval short- range
telemetry (SRM DUAL ANT+, Bluetooth Smart running
heart rate monitor, Schoberer Rad Meßtechnik, Jülich,
Germany). To stipulate the HRmax of each player, the cal-
culation of 220 minus the player's age was used.47,48
2.2.3
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Countermovement jump
To evaluate the maximum height of the players (cen-
timeters—cm), the strength (newtons—N), the power
(watts—W), and the speed (meters per second—m/s)
of the players' jump, the CMJ was performed, using the
Optojump (Optojump Photocell System, Microgate,
TABLE Profile of the elite female players (mean- m, standard
deviation- SD, minimum- minim, maximum- max).
m SD min max
Age (years) 17.9 0.9 19 17
Years of Practice (y) 13 0.7 10 15
Height (cm) 164.57 4.99 158.00 176.00
BM (Kg) 58.50 5.58 50.00 72.70
BMI (Kg/m2) 21.68 1.70 18.60 24.40
Body fat (%) 27.14 4.82 16.40 33.70
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New York, USA).49 The Optojump is an optical measuring
system, which can be used for vertical jump height meas-
urement. It consists of two bars, a transmit and a receive
bar, each measuring 39.4 × 1.2 × 1.6 inches and containing
between 33 and 100 LEDs.49 The system detects any in-
terruption in communication between the bars and cal-
culates their duration. This process makes it possible to
measure flight and contact times during the performance
of a series of jumps with an accuracy of 1/1000 of a sec-
ond.49 Each player performed three successful CMJs from
a standing position, with the hands on the hips. Rest pe-
riods of half a minute between the jumps were provided.
Additionally, players were instructed to jump as high as
possible with both feet.49
2.2.4
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Anticipation
A total of 40 randomized and counterbalanced offensive
scenarios (i.e., mild temperature: 10 clips were presented
pre- and 10 clips post- protocol; hot temperature: 10 clips
were viewed pre- and 10 clips post- protocol) from a
third- person perspective3 were projected onto a screen
(50″ LG UHD 4 K Smart TV—UR80, LG Electronics,
Busan, South Korea). The footage was filmed from 15 m
and 5 m behind the goal using a 16 by nine video cam-
era (DSR 570 DVCAM, Sony, Tokyo, Japan) to ensure
a full view of the field and preserve crucial wide posi-
tional information. The duration of each clip was ap-
proximately 5 s, with an intertrial period of 5 s. A small
circle appeared on screen to indicate the initial position
of the ball just before the start of each clip. The clips
were all occluded 120 ms before the player in possession
of the ball was about to make a pass (i.e., action when
the player attempted to play the ball to a teammate), or
shoot at goal (i.e., when the player makes an attempt to
score a goal), or retain possession (i.e., when the player
has ball possession and attempts to move with the ball).
To obtain the response accuracy (RA) scores calculated
based on participant responses after viewing each clip
(in percentages). An accurate response was recorded if
the participant correctly anticipated the decision of the
player in possession of the ball compared with what
truly happened in the match situation.
2.3
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Study design
Before commencing the task, the test procedure was
explained, the HR device was adjusted and participants
were instructed to perform a 2 min warm- up on the er-
gometer cycle at 75 RPM.50 After and before the inter-
mittent exercise protocol,33 participants were instructed
to perform the CMJ test and, while seated on the cycle
ergometer, were asked to anticipate 10 clips pre- and 10
clips post- protocol, in each temperature condition. The
height and saddle distance of the computer- controlled
stationary cycle ergometer (SRM Ergometer, Schoberer
Rad Meßtechnik, Jülich, Germany) was standardized
for each participant. Based on the players' BM, the high-
intensity loads (4 W/kg) were calculated and, together
with the low- intensity loads (75 W), imported into the
computer. An individualized cycle protocol relative to
players' BM was used to standardize the intensity be-
tween participants. After a warm- up, each player per-
formed the protocol for a total duration of 8 min, divided
into eight blocks of intermittent exercise (each block had
1 min). In each block, players alternated high- intensity
exercise at 4 W/kg for 40 s and low- intensity exercise
at 75 W for 20 s. During the first 15 s, both in periods
of high intensity (4 W/kg) and periods of low intensity
(75 W), the workload was always changed continu-
ously, to avoid abrupt transitions between exchanges of
workload across the protocol. At the end of the 8 min
of protocol, a cooling of 1 min at 75 W was performed.
Throughout the protocol, the players were instructed to
maintain the cycling frequency between 70 and 80 rota-
tions per minute (RPM).
The players were evaluated at three different moments,
with a one- week interval between each test session. The
participants performed the CMJ, the anticipation test (10
clips), the intermittent exercise protocol, the anticipation
test (10 clips), and, lastly, the CMJ in the same order across
all three test sessions. The initial test session was to famil-
iarize the participants with the experimental procedures,
while in the second session participants completed the
entire protocol design exposed under a mild environment
temperature (20°C and 30% rh), and, finally, the partici-
pants completed the protocol design with the influence
of hot environment temperature (38°C and 80% rh)51
(Figure1A,B).
2.4
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Statistical analysis
Before conducting the statistical analysis, data preproc-
essing steps were applied. Our analysis involved the
use of linear mixed models (LMM) after verifying the
necessary assumptions, which include assessing the
normality of residuals and ensuring homoscedasticity
of variances.52 The assumptions of residuals normal-
ity and variances homoscedasticity were assessed thor-
oughly to ensure the validity and reliability of the LMM
results. To examine the assumption of residuals nor-
mality, we conducted several diagnostic tests, namely
the distribution of residuals using histograms, Q- Q
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plots, and probability plots. Variances homoscedastic-
ity was assessed by observing standardized residuals
versus fitted values plots in search for a random pat-
tern. The Breusch- Pagan test was used to determine
whether the variances of residuals were constant across
different levels of the independent variables. All tests
were nonsignificant. We employed a 2 × 2 design to as-
sess the outcomes before and after the protocol in both
nonheated and heated environments. Additionally, a
one- way design was utilized to compare nonheated and
heated environments for the outcomes assessed dur-
ing the protocol. This design allowed us to evaluate the
impact of the protocol under different environmental
conditions. The LMM with unstructured covariance
matrix approach was chosen for both analyses due to
its suitability for handling repeated measures and ac-
counting for within- subject correlations. LMM utilizes
a maximum likelihood solution, which does not assume
complete data.52
The use of LMM allowed us to capture individual vari-
ability and assess the effects of multiple factors simulta-
neously, leading to a more robust and comprehensive
analysis. To enhance the reliability of our analysis, we
adopted a data- driven approach, employing the restricted
maximum likelihood (REML) estimation method, more
appropriate for dealing with unbalanced data, provid-
ing unbiased estimates of fixed effects. All LMM models
were adjusted for BM (Kg) to control for its potential in-
fluence on the outcomes measured. BM was treated as a
covariate to account for its effects, thus enhancing the ac-
curacy of our analyses. We analyzed the data using IBM
SPSS Statistics, version 28.0 (IBM Corp, Armonk, NY)
and the significance level was set at p < 0.05. Partial eta
squared (ηp2) values were provided as a measure of effect
size for all main effects and interactions, considering that
ηp2 = 0.01 represents a small effect, ηp2 = 0.06 represents a
medium effect, and ηp2 = 0.14 represents a large effect.53
2.5
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Results
The average and peak HR data exhibited a linear increas-
ing trend over the protocol (Figure2A). Moreover, and
using LMM, the HR values observed highlighted the re-
markable consistency of the cardiovascular response of
the female football players during the protocol.
The results regarding cycling frequency (RPM) re-
vealed a decreasing performance in the hot when com-
pared to the mild environment, particularly during the
5th block (p < 0.05) (Figure2B). Moreover, the power
(W) generated all over the protocol was significantly
higher in the 4th (p = 0.04) block when participants were
exposed to a mild environment temperature and signifi-
cantly lower in the 8th block (p = 0.04) during the hot
environment condition. Lastly, we observed that cycling
speed were significantly higher during the 5th (p = 0.03)
and 8th blocks (p = 0.02) (Figure2B) when the partici-
pants were exposed to the hot compared with the mild
temperature environment. Additionally, of the 21 elite
female players who participated under the mild environ-
ment temperature conditions there were six withdraw-
als (two at 7th block and eight at 8th block) and when
exposed to hot environment temperature there were 11
withdrawals (one at 6th block, eight at 7th block, and
two at 8th block) before the end of the intermittent ex-
ercise protocol.
FIGURE (A) The experimental task used in the mild environment temperature. (B) The experimental task employed in the hot
environment temperature.
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The CMJ performance results showed a loss of
Strength (N) (F(1,79) = 10.39, p = 0.002; ηp2 = 0.12) after
performing the protocol, regardless of the environmen-
tal temperature, with an average decrease of 97.83 N
(95% CI = 37.41; 158.24). No main effect was found
for hot temperature environment on CMJ strength
(F(1,79) = 0.00, p = 0.955; ηp2 = 0.01). Moreover, there
were significant main effects for protocol on CMJ speed
(m/s) (F(1,79) = 10.96, p = 0.001; ηp2 = 0.12), CMJ power
(F(1,79) = 10.22, p = 0.002; ηp2 = 0.11), and CMJ Heightmax
(F(1,79) = 10.73, p = 0.002; ηp2 = 0.12) (Table2). There
were no effect for hot temperature environment on CMJ
Power (F(1,79) = 0.00, p = 0.958; ηp2 = 0.00), CMJ Heightmax
(F(1,79) = 0.00, p = 0.987; ηp2 = 0.00), and CMJ Speed
(F(1,79) = 0.08, p = 0.783; ηp2 = 0.00). There were no signifi-
cant Protocol*Hot temperature environment interactions
for CMJ Strength (F(1,79) = 0.08, p = 0.780; ηp2 = 0.01),
CMJ power (F(1,79) = 0.08, p = 0.777; ηp2 = 0.00), CMJ
Heightmax (F(1,79) = 0.08, p = 0.780; ηp2 = 0.00), and CMJ
speed (F(1,79) = 0.08, p = 0.783; ηp2 = 0.00).
There was significant main effect for protocol on RA%
(F(1,79) = 44.69, p < 0.001; ηp2 = 0.36), with a reduction in
RA% of 18.26%, from 82.67% to 64.41% (Table2). Also,
there was significant main effect for hot temperature en-
vironment on RA% (F(1,79) = 4.77, p = 0.032; ηp2 = 0.06),
where the RA% decreased 25.8% (Table2). Additionally,
the largest difference was found when comparing the
RA% before the protocol in mild environment tempera-
ture (82.67%) and after the protocol in hot environment
temperature exposure (53.44%). There was no significant
Protocol*Hot temperature environment interaction on
RA% (F(1,79) = 1.31, p = 0.257; ηp2 = 0.02). This finding sug-
gests that the reduction of RA% was higher in heated than
in mild ambient environments (Table2).
FIGURE (A) The players' Heart Rate (HR) performance on the cycle ergometer during the intermittent exercise protocol,33 under
both conditions (mild environment temperature vs hot environment temperature). (B) The players' cycling (RPM), power (W), and speed
(km/h) performance during the intermittent exercise protocol33 on both conditions (mild environment temperature vs hot environment
temperature).
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3
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DISCUSSION
We analyzed the impact of a hot environmental tempera-
ture on physical and perceptual- cognitive performance in
elite female football players while performing an intermit-
tent exercise protocol. We predicted that performance on
CMJ measures and our test of anticipation performance
would be lower after the intermittent exercise protocol,
regardless of the temperature exposure. We further hy-
pothesized that hot environment temperature would neg-
atively impact performance on the anticipation test in our
sample of elite female football players.
FIGURE (Continued)
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The results of this study confirmed the formulated hy-
pothesis, revealing that the intermittent exercise protocol
had a significant adverse impact on all measures related
to CMJ as well as the anticipation performance of female
football players. Moreover, it was evident that hot tem-
perature environment (38°C and 80% rh) had a negative
influence on the players' ability to anticipate.
During the eight blocks of the intermittent protocol,
players demonstrated a linear increase in average HR and
peak HR throughout the test. From the 5th block onwards,
players had already reached, on average, 90% of their peak
HR. The average HR was higher across all blocks when
the players performed the protocol under a hot when
compared to a mild temperature. The same pattern was
observed with the peak HR, which was higher when ex-
posed to a hot temperature. Our findings support previ-
ous research, which showed that HR was higher during
hot conditions, when compared to mild temperature
exposure across all the cycling intermittent sprint proto-
col.2 Additionally, the gradual increase of the players' HR
across the intermittent exercise protocol suggests that fe-
male players were experiencing an increase in their phys-
ical exertion levels throughout the protocol, suggesting
that the exercise intensity and cardiovascular demands
increased progressively, ending with physical stress.54
Furthermore, the observed differences in average HR
between hot and mild temperatures emphasized the in-
fluence of environment on cardiac response during exer-
cise.55 Hot temperature tends to increase thermal overload
on the body, which can result in greater cardiovascular de-
mand to help dissipate heat and maintain adequate body
temperature,56 leading to peripheral fatigue.57 We can
presume that all the participants experienced the physi-
ological strain58,59 imposed by the cycling- based protocol
used, since metabolic heat production experienced during
running activity tends to be higher.60 Moreover, exces-
sive heat can impair efficient muscle contraction, leading
to decreased strength, endurance, and coordination.61
Donnan etal.2 reported similar findings when male foot-
ball players significantly reduced their workload during
the second half of a cycling intermittent sprint protocol in
heat conditions.
Moreover, when exposed to a hot environmental tem-
perature, the players did not decrease their cycling ca-
dence, expressed in RPM, resulting in a higher average
speed, and generating more Watts at the end of the pro-
tocol. These results suggested that, even with the increase
in thermal stress, the players were able to maintain or
even improve their displacement on the cycle ergometer,
demonstrating improved performance compared to the
mild environment temperature.
The results for the CMJ test revealed that female players
decreased their CMJ performance during both temperature
TABLE The results obtained of the linear mixed model for comparisons before and after protocol considering both ambient environments.
Mild ambient temperature Hot ambient temperature Protocol effect
Hot temperature
effect
Protocol × Hot
temperature effect
Variables Before protocol After protocol Before protocol After protocol F(1,79)p F(1,79)p F(1,79)p
Heightmax (cm) 29.82 ± 0.68 27.38 ± 0.69 29.64 ± 0.68 27.58 ± 0.69 10.73 0.002 0.00 0.987 0.08 0.780
Strength (N) 1886.37 ± 30.36 1780.02 ± 30.37 1879.58 ± 30.36 1790.27 ± 30.37 10.39 0.002 0.00 0.955 0.08 0.780
Power (W) 22 865.75 ± 619.46 20 709.81 ± 619.70 22 722.23 ± 619.45 20 918.36 ± 619.74 10.22 0.002 0.00 0.958 0.08 0.777
Speed (m/s) 12.08 ± 0.14 12.04 ± 0.14 11.61 ± 0.14 11.57 ± 0.14 10.96 0.001 0.08 0.783 0.08 0.783
Response accuracy (%) 82.67 ± 3.30 64.41 ± 3.30 79.24 ± 3.30 53.44 ± 3.30 44.69 <0.001 4.77 0.032 1.31 0.257
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conditions, albeit the physical performance was more af-
fected by the intermittent exercise protocol than under a
hot environment temperature. One of the main observa-
tions was the reduction in the Heightmax of the jump, which
indicates that the intermittent exercise protocol affected the
ability of the players to generate vertical momentum and
to increase vertical height. The decrease in the maximum
jump height can be attributed to peripheral muscle fatigue
caused by the intermittent effort performed,62 resulting in a
lower ability to produce the power needed to rise properly
during the CMJ.63 Hence, both intermittent effort and hot
environment temperature exposure reduced the ability to
generate muscle strength and may affect the proper activa-
tion of motor units and muscle contractility, respectively.
Another important finding was the decrease in the
jumping speed of the players after the performance of the
intermittent protocol, exacerbated by the exposure to hot
environment temperature conditions. The reduction in
jumping speed suggests a decrement in movement effi-
ciency and in the ability to produce the adequate amount
of explosive force needed to achieve maximum speed.63
Therefore, this factor can be pointed out as the cause of the
loss of speed in the CMJ performance of the players, with
this negative impact increasing when the female players
were exposed to hot environment temperature conditions.
The present study also provided a revealing insight into
the impact of the intermittent protocol on the perceptual-
cognitive performance of female football players. After
executing the intermittent protocol, there was a clear de-
crease in the accuracy of the players' responses, indicating
a negative influence on their cognitive function. These
findings align with research by Casanova et al.3 who
showed that a fatigue- inducing protocol negatively influ-
enced the accuracy of judgments in male football players.
It appears that physiological workload has detrimental
effects on the perceptual- cognitive processes underpin-
ning anticipation.13 Similarly, a drop in performance has
been observed under high- intensity exercise, probably at-
tributed to the brain's finite resources.19
However, the scenario became even more challenging
when the same protocol design was implemented under
hot environment temperature conditions. In this context,
the accuracy of the players' responses was further impaired,
highlighting the sensitivity of these players to environmen-
tal variations during the intermittent exercise protocol.
To the best of our knowledge, no researchers have tested
female football players using an intermittent exercise pro-
tocol while manipulating environmental conditions (air
temperature and humidity). The results of the present study
showed that exposure to heat led to a decrease in anticipa-
tion performance in elite female players. Our results mirror
those reported by Donnan etal.2 who examined the effects
of hot (32°C, 50% rh) and mild environmental temperature
(18°C, 50% rh) exposure on physical performance and
soccer- specific decision- making in male football players
after completing a 92- min intermittent cycling sprint pro-
tocol. The results showed that the decision- making was
impaired in the hot compared to the mild temperature
condition. Similarly, Alder etal.64 observed that response
accuracy decreased in the separate physical and mental
load conditions, when compared to baseline and worsened
further in the combined load condition. The ability to an-
ticipate is a fundamental skill for football players since it
allows them to make quick and efficient judgments during
matches,65 and it is negatively affected in hot temperature
environments limiting the cognitive functions.66
4
|
CONCLUSIONS
Our findings revealed that when elite female football play-
ers were subjected to the intermittent exercise protocol
under two different conditions (hot and mild environ-
ment temperature) a reduction in performance was noted
on a CMJ test as sell as their ability to anticipate oppo-
nents' offensive actions. This latter finding suggests that
while physical and cognitive performance was affected in
both groups, heat exposure significantly exacerbated the
decline in anticipation performance, highlighting the im-
portance of specific training and conditioning strategies to
deal with adverse environmental conditions.
5
|
PERSPECTIVE
While some previous reports have evaluated the effects of
inducing fatigue on the physical abilities of female foot-
ballers,41,42 and the effect of fatigue on the mental abili-
ties of the players,43 the present study should encourage
the scientific community to undertake further research on
this topic. We hypothesized that female footballers would
decline their efficiency to anticipate during matches in
hot compared to mild temperature environments players.
Moreover, our findings are essential to consider the envi-
ronmental conditions during football training and com-
petitions. Measures such as adequate hydration, gradual
adaptation to the heat or cold, and the implementation of
cooling strategies can be adopted to minimize the nega-
tive impacts of heat on the physical performance of the
players. In future, researchers should consider how per-
formance is impacted by different climates and what role
acclimatization players (male and female) in this response
to heat stress. In addition, adjustments in training times,
training loads, and exercise intensity may be necessary to
ensure effective training and mimic the exposure of hot
temperature environments.
10 of 12
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POMPEO etal.
AUTHOR CONTRIBUTIONS
AP was involved in research concept and study design,
data collection, data analysis and interpretation, and writ-
ing the manuscript. JA, JAC, JV- A, NG, and SG- V were
involved in writing the manuscript, and reviewing/edit-
ing a draft of the manuscript. ELRC was involved in data
collection and data analysis and interpretation. AMW was
involved in research concept, writing the manuscript, re-
viewing/editing a draft of the manuscript, and final ap-
proval of the article to be published. FC was involved in
research concept and study design, data analysis and in-
terpretation, writing the manuscript, and final approval of
the article to be published.
ACKNOWLEDGEMENTS
Thanks to all the staff of Jamor High Performance Center
(Lisbon, Portugal), who collaborated to carry out this
study.
FUNDING INFORMATION
This study had no funding.
CONFLICT OF INTEREST STATEMENT
No potential conflict of interest was reported by the
authors.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are avail-
able from the corresponding author upon reasonable
request.
ORCID
Alberto Pompeo https://orcid.org/0000-0001-5259-8612
José Afonso https://orcid.org/0000-0002-2038-393X
Everton Luis Rodrigues Cirillo https://orcid.
org/0000-0001-5540-4086
Júlio A. Costa https://orcid.org/0000-0002-8225-8667
José Vilaça- Alves https://orcid.
org/0000-0001-5399-7797
Nuno Garrido https://orcid.org/0000-0002-8105-7580
Sixto González- Víllora https://orcid.
org/0000-0003-2473-5223
Filipe Casanova https://orcid.org/0000-0002-9696-9355
REFERENCES
1. Nassis GP, Brito J, Dvorak J, Chalabi H, Racinais S. The associa-
tion of environmental heat stress with performance: analysis of
the 2014 FIFA world cup Brazil. Br J Sports Med. 2015;49(9):609-
613. doi:10.1136/bjsports- 2014- 094449
2. Donnan KJ, Williams EL, Stanger N. The effect of exercise-
induced fatigue and heat exposure on soccer- specific decision-
making during high- intensity intermittent exercise. PLoS One.
2022;17(12):e0279109. doi:10.1371/journal.pone.0279109
3. Casanova F, Garganta J, Silva G, Alves A, Oliveira J, Williams
AM. Effects of prolonged intermittent exercise on perceptual-
cognitive processes. Med Sci Sports Exerc. 2013;45(8):1610-
1617. doi:10.1249/mss.0b013e31828b2ce9
4. Mohr M, Mujika I, Santisteban J, etal. Examination of fatigue
development in elite soccer in a hot environment: a multi-
experimental approach. Scand J Med Sci Sports. 2010;20:125-
132. doi:10.1111/j.1600- 0838.2010.01217.x
5. Racinais S, Alonso J- M, Coutts AJ, etal. Consensus recommen-
dations on training and competing in the heat. Scand J Med Sci
Sports. 2015;25:6-19. doi:10.1111/sms.12467
6. Binkley HM, Beckett J, Casa DG, Kleiner DM, Plummer PE.
Position statement: exertional heat illnesses. J Athl Train.
2002;37(3):329-343.
7. Williams AM, Jackson RC. Anticipation and Decision Making in
Sport. Routledge Abingdon; 2019. doi:10.4324/9781315146270
8. Carling C, Dupont G, Le Gall F. The effect of a cold environ-
ment on physical activity profiles in elite soccer match- play. Int
J Sports Med. 2011;32:542-545. doi:10.1055/s- 0031- 1273711
9. Meyer F, Andrade R. Desidratação e importância da reposição
de líquidos durante o exercício prolongado no calor. Rev Perfil.
1999;3(3):12-16. doi:10.11606/t.3.2000.tde- 12092022- 080123
10. Schlader ZJ, Stannard SR, Mündel T. Evidence for thermoregu-
latory behavior during self- paced exercise in the heat. J Therm
Biol. 2011;36(7):390-396. doi:10.1016/j.jtherbio.2011.07.002
11. Özgünen K, Kurdak S, Maughan R, etal. Effect of hot envi-
ronmental conditions on physical activity patterns and tem-
perature response of football players. Scand J Med Sci Sports.
2010;20:140-147. doi:10.1111/j.1600- 0838.2010.01219.x
12. Chen Y, Tao M, Liu W. High temperature impairs cognitive per-
formance during a moderate intensity activity. Build Environ.
2020;186:107372. doi:10.1016/j.buildenv.2020.107372
13. Casanova F, Esteves PT, Padilha MB, Ribeiro J, Williams
AM, Garganta J. The effects of physiological demands on vi-
sual search Behaviours during 2 vs. 1+ GK game situations in
football: an in- situ approach. Front Psychol. 2022;13:885765.
doi:10.3389/fpsyg.2022.885765
14. Williams AM, Ward P, Knowles JM, Smeeton NJ. Anticipation
skill in a real- world task: measurement, training, and transfer
in tennis. J Exp Psychol Appl. 2002;8(4):259-270. doi:10.1037/
1076- 898x.8.4.259
15. Mohr M, Krustrup P. Heat stress impairs repeated jump abil-
ity after competitive elite soccer games. J Strength Cond Res.
2013;27(3):683-689. doi:10.1097/JSC.0b013e31825c3266
16. Massaro AN, Campbell HE, Metzler M, etal. Effect of tempera-
ture on heart rate variability in neonatal intensive care unit pa-
tients with hypoxic ischemic encephalopathy. Pediatr Crit Care
Med. 2017;18(4):349-354. doi:10.1097/pcc.0000000000001094
17. Hedley AM, Climstein M, Hansen R. The effects of acute heat
exposure on muscular strength, muscular endurance, and mus-
cular power in the euhydrated athlete. J Strength Cond Res.
2002;16(3):353-358. doi:10.1519/1533- 4287(2002)016<0353:teo
ahe>2.0.co;2
18. Donnan K, Williams EL, Stanger N. The effects of heat expo-
sure during intermittent exercise on physical and cognitive
performance among team sport athletes. Percept Mot Skills.
2021;128(1):439-466. doi:10.1177/0031512520966522
19. McMorris T. The acute exercise- cognition interaction: from
the catecholamines hypothesis to an interoception model. Int
|
11 of 12
POMPEO etal.
J Psychophysiol. 2021;170:75-88. doi:10.1016/j.ijpsycho. 2021.
10.005
20. Eysenck MW, Derakshan N, Santos R, Calvo MG. Anxiety and
cognitive performance: attentional control theory. Emotion.
2007;7(2):336-353. doi:10.1037/1528- 3542.7.2.336
21. Smith MR, Coutts AJ, Merlini M, Deprez D, Lenoir M, Marcora
SM. Mental fatigue impairs soccer- specific physical and tech-
nical performance. Med Sci Sports Exerc. 2016;48(2):267-276.
doi:10.1249/mss.0000000000000762
22. Badin OO, Smith MR, Conte D, Coutts AJ. Mental fatigue: im-
pairment of technical performance in small- sided soccer games.
Int J Sports Physiol Perform. 2016;11(8):1100-1105. doi:10.1123/
ijspp.2015- 0710
23. Impellizzeri FM, Marcora SM. Test validation in sport physi-
ology: lessons learned from clinimetrics. Int J Sports Physiol
Perform. 2009;4(2):269-277. doi:10.1123/ijspp.4.2.269
24. Carling C. Interpreting physical performance in profes-
sional soccer match- play: should we be more pragmatic in
our approach? Sports Med. 2013;43:655-663. doi:10.1007/
s40279- 013- 0055- 8
25. Russell M, Kingsley M. Influence of exercise on skill profi-
ciency in soccer. Sports Med. 2011;41:523-539. doi:10.2165/ 1158
9130- 000000000- 00000
26. Kempton T, Sirotic AC, Coutts AJ. A comparison of physical and
technical performance profiles between successful and less-
successful professional rugby league teams. Int J Sports Physiol
Perform. 2017;12(4):520-526. doi:10.1123/ijspp.2016- 0003
27. Nédélec M, McCall A, Carling C, Legall F, Berthoin S, Dupont
G. Recovery in soccer. Sports Med. 2012;42(12):997-1015.
doi:10.1007/BF03262308
28. Young CM, Luo W, Gastin PB, Dwyer DB. Understanding
the relative contribution of technical and tactical perfor-
mance to match outcome in Australian football. J Sports Sci.
2020;38(6):676-681. doi:10.1080/02640414.2020.1724044
29. Roca A, Ford PR. Decision- making practice during coaching ses-
sions in elite youth football across European countries. Sci Med
Footb. 2020;4(4):263-268. doi:10.1080/24733938.2020.1755051
30. Casa DJ, DeMartini JK, Bergeron MF, etal. National Athletic
Trainers' Association Position Statement: exertional heat ill-
nesses. J Athl Train. 2015;50(9):986-1000. doi:10.4085/ 1062- 60
50- 50.9.07
31. Buchheit M, Simpson BM. Player- tracking technology:
half- full or half- empty glass? Int J Sports Physiol Perform.
2017;12(s2):S2-S35. doi:10.1123/ijspp.2016- 0499
32. Kerhervé HA, Stewart DG, McLellan C, Lovell D. Fatigue in-
dices and perceived exertion highlight ergometer specific-
ity for repeated sprint ability testing. Front Sports Act Living.
2020;2:45. doi:10.3389/fspor.2020.00045
33. Lemmink KA, Visscher C. Effect of intermittent exercise on
multiple- choice reaction times of soccer players. Percept Mot
Skills. 2005;100(1):85-95. doi:10.2466/pms.100.1.85- 95
34. Benjamin CL, Sekiguchi Y, Morrissey MC, et al. The effects
of hydration status and ice- water dousing on physiological
and performance indices during a simulated soccer match in
the heat. J Sci Med Sport. 2021;24(8):723-728. doi:10.1016/j.
jsams.2021.05.013
35. Clarke N, Maclaren D, Reilly T, Drust B. Carbohydrate ingestion
and pre- cooling improves exercise capacity following soccer-
specific intermittent exercise performed in the heat. Eur J Appl
Physiol. 2011;111:1447-1455. doi:10.1007/s00421- 010- 1771- 5
36. Coull NA, Watkins SL, Aldous JW, etal. Effect of tyrosine in-
gestion on cognitive and physical performance utilising an
intermittent soccer performance test (iSPT) in a warm envi-
ronment. Eur J Appl Physiol. 2015;115:373-386. doi:10.1007/
s00421- 014- 3022- 7
37. Edwards AM, Mann ME, Marfell- Jones MJ, Rankin DM,
Noakes TD, Shillington DP. Influence of moderate dehydra-
tion on soccer performance: physiological responses to 45 min
of outdoor match- play and the immediate subsequent perfor-
mance of sport- specific and mental concentration tests. Br J
Sports Med. 2007;41(6):385-391. doi:10.1136/bjsm.2006.033860
38. Venable AS, Williams RR, McFarlin BK. Gender differences
in skin and core body temperature during exercise in a hot,
humid environment. Int J Exerc Sci: Conference Proceedings.
2013;32:11-14. doi:10.5604/20831862.1124569
39. Yanovich R, Ketko I, Charkoudian N. Sex differences in human
thermoregulation: relevance for 2020 and beyond. Physiology.
2020;35(3):177-184. doi:10.1152/physiol.00035.2019
40. Assembly G. Resolution adopted by the general Assembly
on 11 September 2015. New York: United Nations. 2015.
doi:10.18356/53ee9ade- en
41. Wickham KA, Wallace PJ, Cheung SS. Sex differences in the
physiological adaptations to heat acclimation: a state- of- the-
art review. Eur J Appl Physiol. 2021;121:353-367. doi:10.1007/
s00421- 020- 04550- y
42. Torreblanca- Martínez V, Nevado- Garrosa F, Otero- Saborido
FM, Gonzalez- Jurado JA. Effects of fatigue induced by
repeated- sprint on kicking accuracy and velocity in female soc-
cer players. PLoS One. 2020;15(1):e0227214. doi:10.1371/jour-
nal.pone.0227214
43. Krustrup P, Zebis M, Jensen JM, Mohr M. Game- induced fa-
tigue patterns in elite female soccer. J Strength Cond Res.
2010;24(2):437-441. doi:10.1519/JSC.0b013e3181c09b79
44. Thompson CJ, Smith A, Coutts AJ, etal. Understanding the
presence of mental fatigue in elite female football. Res Q Exerc
Sport. 2022;93(3):504-515. doi:10.1080/02701367.2021.1873224
45. Verma J, Verma P. Determining Sample Size and Power in
Research Studies. Springer; 2020. doi:10.1007/978- 981- 15- 5204- 5
46. McKay AK, Stellingwerff T, Smith ES, et al. Defining train-
ing and performance caliber: a participant classification
framework. Int J Sports Physiol Perform. 2021;17(2):317-331.
doi:10.1123/ijspp.2021- 0451
47. Robergs RA, Landwehr R. The surprising history of the"
HRmax= 220- age" equation. J Exerc Physiol Online. 2002;5(2):1-
10. doi:10.1097/00005768- 200205001- 00429
48. Tanaka H, Monahan KD, Seals DR. Age- predicted maximal
heart rate revisited. J Am Coll Cardiol. 2001;37(1):153-156.
doi:10.1016/s0735- 1097(00)01054- 8
49. Jiménez- Reyes P, Samozino P, Pareja- Blanco F, et al. Validity
of a simple method for measuring force- velocity- power pro-
file in countermovement jump. Int J Sports Physiol Perform.
2017;12(1):36-43. doi:10.1123/ijspp.2015- 0484
50. Karsten B, Larumbe- Zabala E, Kandemir G, Hazir T, Klose A,
Naclerio F. The effects of a 6- week strength training on crit-
ical velocity, anaerobic running distance, 30- M sprint and
Yo- Yo intermittent running test performances in male soccer
players. PLoS One. 2016;11(3):e0151448. doi:10.1371/journal.
pone.0151448
51. No M, Kwak H- B. Effects of environmental temperature on
physiological responses during submaximal and maximal
12 of 12
|
POMPEO etal.
exercises in soccer players. Integr Med Res. 2016;5(3):216-222.
doi:10.1016/j.imr.2016.06.002
52. Field A. Discovering Statistics Using IBM SPSS Statistics. 4th ed.
Sage Publications; 2013. doi:10.1024/1012- 5302/a000397
53. Lakens D. Sample size justification. Collabra: Psychol.
2022;8(1):33267. doi:10.1525/collabra.33267
54. Chalmers S, Esterman A, Eston R, Bowering KJ, Norton K.
Short- term heat acclimation training improves physical per-
formance: a systematic review, and exploration of physiolog-
ical adaptations and application for team sports. Sports Med.
2014;44:971-988. doi:10.1007/s40279- 014- 0178- 6
55. Smith DL, Petruzzello S, Kramer J, Misner J. The effects of dif-
ferent thermal environments on the physiological and psycho-
logical responses of firefighters to a training drill. Ergonomics.
1997;40(4):500-510. doi:10.1080/001401397188125
56. Garcia CK, Renteria LI, Leite- Santos G, Leon LR, Laitano
O. Exertional heat stroke: pathophysiology and risk fac-
tors. Brit Med J. 2022;1(1):e000239. doi:10.1136/bmjmed- 20
22- 000239
57. Brazaitis M, Skurvydas A. Heat acclimation does not reduce the
impact of hyperthermia on central fatigue. Eur J Appl Physiol.
2010;109:771-778. doi:10.1007/s00421- 010- 1429- 3
58. Nybo L, Nielsen B. Hyperthermia and central fatigue during
prolonged exercise in humans. J Appl Physiol. 2001;91(3):1055-
1060. doi:10.1152/jappl.2001.91.3.1055
59. Reilly T, Drust B, Clarke N. Muscle fatigue during football
match- play. Sports Med. 2008;38:357-367. doi:10.2165/0000
7256- 200838050- 00001
60. Junge N, Jørgensen R, Flouris AD, Nybo L. Prolonged self-
paced exercise in the heat–environmental factors affecting
performance. Temperature. 2016;3(4):539-548. doi:10.1080/
23328940
61. Chaâri N, Frikha M. Ten- minute warm- up in hot climate best
assists thermal comfort, muscular power output, and fatigue,
during soccer- specific repeated- sprint ability. Biol Sport.
2022;39(1):37-43. doi:10.5114/biolsport.2021.102808
62. Samuel MN, Holcomb WR, Guadagnoli MA, Rubley MD,
Wallmann H. Acute effects of static and ballistic stretch-
ing on measures of strength and power. J Strength Cond Res.
2008;22(5):1422-1428. doi:10.1519/jsc.0b013e318181a314
63. Loturco I, Pereira LA, Kobal R, etal. Do asymmetry scores in-
fluence speed and power performance in elite female soccer
players? Biol Sport. 2019;36(3):209-216. doi:10.5114/biolsport.
2019.85454
64. Alder D, Broadbent DP, Poolton J. The combination of physical
and mental load exacerbates the negative effect of each on the
capability of skilled soccer players to anticipate action. J Sports
Sci. 2021;39(9):1030-1038. doi:10.1080/02640414.2020.1855747
65. Sun H, Soh KG, Roslan S, Wazir MRWN, Soh KL. Does men-
tal fatigue affect skilled performance in athletes? A systematic
review. PLoS One. 2021;16(10):e0258307. doi:10.1371/journal.
pone.0258307
66. Hocking C, Silberstein RB, Lau WM, Stough C, Roberts W.
Evaluation of cognitive performance in the heat by functional
brain imaging and psychometric testing. Comp Biochem Physiol
Part A Mol Integr Physiol. 2001;128(4):19-734. doi:10.1016/
s1095- 6433(01)00278- 1
How to cite this article: Pompeo A, Afonso J,
Cirillo ELR, et al. Impact of temperature on physical
and cognitive performance in elite female football
players during intermittent exercise. Scand J Med Sci
Sports. 2024;34:e14646. doi:10.1111/sms.14646
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