RESEARCH ARTICLE
A 7-min halftime jog mitigated the reduction
in sprint performance for the initial 15-min of
the second half in a simulated football match
Sooil Bang1, Jihong ParkID2*
1 Athletic Training Laboratory, Graduate School of Physical Education, Kyung Hee University, Yongin, Korea,
2 Department of Sports Medicine, Athletic Training Laboratory, Kyung Hee University, Yongin, Korea
* jihong.park@khu.ac.kr
Abstract
This study compared the effects of a 7-min shuttle jog during halftime to a control condition
(seated rest) on subsequent athletic performance and lower-leg temperature in the second
half. Eighteen male football players (22 years, 179 cm, 70 kg, 10 years of athletic career) ran-
domly performed a 20-m shuttle jog (at an intensity of 70% of heart rate maximum) and a
seated rest (sitting on a bench) during halftime in two separate sessions. A 5-min football sim-
ulation protocol consisting of football-specific activities (jumping, sprinting, kicking, passing,
and dribbling at various intensities and distances) was repeated nine times to mimic the first
and second half of a football match. Athletic performance (maximal vertical jump height, 20-
m sprint time, and the Arrowhead agility test time) recorded during a 15-min period were aver-
aged to represent each time point (first half: T1 to T3; second half: T4 to T6). Lower-leg skin
and muscle (using the insulation disk technique) temperature was recorded before and after
the first and second half. There was no condition effect over time in maximal vertical jump:
F5,187 = 0.53, p = 0.75, Arrowhead agility test time: F5,187 = 1.25, p = 0.29, and lower-leg tem-
perature (skin: F3,119 = 1.40, p = 0.25; muscle: F3,119 = 1.08, p = 0.36). The 20-m sprint time
between conditions during the initial 15-min of the second half was different (condition × time:
F5,187 = 2.42, p = 0.04) that subjects who performed the shuttle jog ran 0.09 sec faster (3.08
sec, p = 0.002, ES = 0.68), as compared with those who did the seated rest (3.17 sec). The
results of our study confirmed that a decremental effect of the static rest on sprinting perfor-
mance during the initial period of the second halftime can be attenuated by a halftime warm-up.
Introduction
A deterioration in athletic performance during the second half, as compared with the first half
in football matches is common. For example, professional footballers have shown a decline in
the total distance covered [1] and the distance covered by high-intensity running [2]. Within
the second half, the first 15-min is the time that players’ physical performance is the lowest [3–
5]. Since players’ performance generally improves afterwards, this performance decrement
during the initial phase of the second half is thought to be from the lack of recovery from the
first half and/or preparation for high-intensity activities in the second half. Therefore, there is
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OPEN ACCESS
Citation: Bang S, Park J (2022) A 7-min halftime
jog mitigated the reduction in sprint performance
for the initial 15-min of the second half in a
simulated football match. PLoS ONE 17(7):
e0270898. https://doi.org/10.1371/journal.
pone.0270898
Editor: Shigehiko Ogoh, Tokyo Joshi Ika Daigaku
Toyo Igaku Kenkyujo Clinic, JAPAN
Received: December 14, 2021
Accepted: June 19, 2022
Published: July 19, 2022
Copyright: © 2022 Bang, Park. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: All relevant data are
within the paper and its Supporting information
files.
Funding: The author(s) received no specific
funding for this work.
Competing interests: The authors have declared
that no competing interests exist.
a need for halftime conditioning strategies, which help not only to enhance recovery from
fatigue but also to be ready for the second half [6, 7].
Traditional static halftime rest (e.g., sitting on a bench) could change the body’s regulatory
systems (e.g., autonomic nervous, thermoregulatory, and cardiovascular), resulting in a reduc-
tion of the core body and working muscle temperature [8]. For example, a 10-min passive rest
after a warm-up activity can result in a 0.4˚C decrease in body temperature, which could fur-
ther lead to a 13% reduction in maximal vertical jump capacity [9]. Therefore, taking a passive
rest during halftime is not considered as a recommended halftime strategy to prepare for the
subsequent performance in the second half in terms of maintaining the “warmed-up body”.
To preserve exercise-induced heat, halftime conditioning strategies such as cycling [10], plyo-
metric and agility exercise [11], football-specific activity [12], and jogging [8, 13] have previ-
ously been tested. Common endpoints to determine the effectiveness of such halftime
activities include body temperature (core [12] and muscle [14]) and athletic performance
(sprint time [10, 11] and maximal vertical jump height [13]).
While the aforementioned studies reported an advantage in favour of warming-up during
halftime, as compared with a passive rest, a couple of limitations still need to be addressed.
First, the previous halftime warm-up strategies [8, 13] were examined in actual football
matches. Although the results of these filed studies are advantageous for ecological validity, the
sources of variation among subjects (e.g., movements or distance covered) are potential for
data heterogeneity; thus, the results might be confounded. Although there have been studies
[10, 12, 14, 15] using simulation protocols across interventions, the protocols were not con-
sisted of football-related running and kicking activities [10, 15] or the effectiveness was exam-
ined in relatively small samples (n = 7 [12]; n = 10 [15]; n = 10 [14]; n = 13 [10]). Recently, a
90-min long simulated football match (a 5-min of football simulation protocol: FSP ×9 to
mimic the first and second halves) with a fixed distance and intensity has been introduced and
validated [3]. The recorded average heart rate (163 bpm) and energy expenditure (1,227 kcal)
during the simulated football match fell within the typical ranges of real-football matches
(heart rate: 150 and 175 bpm [16]; calorie expenditure (1,200 to 1,500 kcal) [17]). Distance cov-
ered by running without ball possession in this simulation protocol (maximal: 720-m; submax-
imal 1,514-m) was also similar to an actual football match (maximal: 542 ± 214-m;
submaximal 1,590 ± 488-m) [18].
Therefore, the purpose of this study was to quantify the effect of a halftime shuttle jog and
seated rest on the second half performance in collegiate footballers. For the objective compari-
sons (without possible confounders), the previously validated FSP [3] was employed using a
within-subject design. The endpoints were athletic performance (maximal vertical jump
height, 20-m sprint time, and Arrowhead agility test time performed during the football simu-
lation), lower-leg temperature (skin and muscle), and heart rate during a 90-min simulated
football matches. A previous study [8] observed a decrement in core and muscle (quadriceps)
temperature with a static rest during halftime, which further impaired sprinting performance.
Another study [13] reported that a halftime shuttle jog prevented sprinting and jumping per-
formance deterioration in the initial period of the second half. According to the previous data
[8, 13], we hypothesised that players who performed a shuttle jog would show better athletic
performance and higher lower-leg temperature than those who experienced a seated rest.
Materials and methods
Study design and experimental approach
A two-way (condition × time) crossover field study with repeated measures on time was used.
Subjects randomly performed one of the two different conditioning strategies (shuttle jog or
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seated rest) during halftime each session. The random order was generated by a spreadsheet
software. Dependent measurements were athletic performance (maximal vertical jump height,
20-m sprint time, and Arrowhead agility test time), lower-leg temperature (skin and muscle),
and heart rate.
A 5-min FSP [3] (Fig 1) consisting of football-related activities (a full videoclip is available
at https://www.youtube.com/watch?v=9FgWbWMWAa0) were repeated nine times to make
up each half of a football match. The athletic performance and heart rate data recorded during
the three consecutive FSPs were combined (a total time of 15-min); thus six-time points (first
half: T1 through T3; second half: T4 through T6) were analysed and compared. The lower-leg
temperatures were measured before and after the first and second half (four time points).
Subjects visited the football pitch (regular-sized natural grass) same time of day on Two dif-
ferent sessions, each 72-h apart. Subjects were asked to maintain their normal diet and wear
the same socks and football stud throughout the experimental period and allowed to consume
1.5 L of water during each session (500 mL during each of the first and second halves and half-
time). Data were not collected on rainy days. Air temperature and relative humidity were
recorded with a digital thermometer (Kestrel Drop, Nielsen-Kellerman Co., Boothwyn, PA,
USA) each session and were not different throughout the data collection period (air tempera-
ture: t = 0.15, p = 0.87; relative humidity: t = –0 .52, p = 0.60). The average values of air temper-
ature and relative humidity during the data collection period were 17.5 ± 4.6˚C and
40.2 ± 15.9%, respectively.
Participants
Eighteen male elite collegiate footballers (age: 22 ± 1 years; height: 179 ± 4 cm; mass: 70 ± 5 kg)
volunteered for this study. All subjects had to be registered in the Korea Football Association
(years of training: 10 ± 1 years) and football trained at least six years. Subjects were excluded if
they had any musculoskeletal lower-extremity injury in the past six months, history of back or
Fig 1. Football simulation protocol. This protocol was repeated three times during each time point. The protocol was to follow the
numerical order as follows (1: 10-m run, 2: 10-m short pass ×2, 3: 10-m jog, 4: 40-m Arrowhead agility test, 5: 10-m run, 6: maximal
vertical jump ×2, 7: 10-m side step, 8: 20-m walk, 9: 10-m dribble, 10: 10-m walk, 11: 30-m long kick ×2, 12: 10-m run, 13: 10-m back
step, 14: 10-m side step, 15: 10-m jog, 16: 10-m short pass ×2, 17: 10-m jog, 18: 20-m sprint, 19: 10-m dribble, 20: walk, 21: 30-m long
kick ×2, 22: 10-mjog, 23: 40-m Arrowhead agility test, 24: 10-m back step, 25: maximal vertical jump ×2, 26: 10-m side step, 27: jog,
28: 10-m walk, 29: 20-m sprint).
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lower-extremity surgery, or neuromuscular disorders. All subjects read the study procedures,
approved by the university’s institutional review board (protocol #: KHSIRB-18-012), and gave
written informed consent prior to taking part in the study.
Testing procedures
Upon arrival to the football pitch, testing procedures were instructed and written informed
consent were obtained. Each session began with a self-directed 10- to 15-min warm-up (light
jog and dynamic stretch). Subjects were equipped with the thermistor probes and heart rate
monitor, the baseline lower-leg temperature and heart rate were recorded 1-min before the
first half (Fig 2). After the thermistor probes were detached, subjects performed nine repeti-
tions of the 5-min FSP (Fig 1) to represent the first and second halves. Once halftime begun,
subjects walked to the bench (took 1-min), sat on the shaded bench (located in the sideline
Fig 2. Testing procedures. Subjects were randomly experienced the condition of shuttle jog or seated rest each session. Heart rate was
recorded throughout the experiment. The arrows indicate time points for lower-leg temperature measurements. FSP: football
simulation protocol.
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area), and rested for 6-min while consuming water (500 mL). During this time, temperature
probes were attached again to the lower-leg. After the temperature data were taken, subjects
randomly performed either condition (shuttle jog or seated rest) for the next 7-min at each ses-
sion. Subjects performed a 20-m shuttle jog at a constant intensity (average 70% of heart rate
maximum recorded during the first half) on a football pitch [8]. To maintain the intensity of
the shuttle jog, we continuously monitored their heart rate and gave continuous verbal feed-
back (e.g., “slow down or a little faster”) to players. For the seated rest, subjects maintained the
position (sitting on the bench) for another 7-min. During the last minute of halftime, lower-
leg temperatures were taken again for both conditions. Subjects then completed another nine
repetitions of the FSP for the second half (same activity as the first half). The temperature
probes were attached again to the lower-leg immediately after the second half. Heart rate was
recorded throughout the whole experiment. For the second session, subjects came back for
another condition and went through the same experimental procedures.
Endpoints
For the maximal vertical jump, subjects were instructed to place their feet on the pitch within a
triangle area (Fig 1) and to vertically jump as high as they could using both legs. Take-off move-
ments were self-selected and performed pre-stretch using their lower-extremity joints and both
arms’ swinging. Two cameras were set up as 240 fps with 1/1000 shutter speed: One camera (C1
in Fig 1: 1-m away from the center of the jumping area and located 1-m high from the grass)
videotaped subjects’ feet to determine flight time while the other camera (C2: 1-m away from
the centre of the jumping area and located 20 cm high from the grass) videotaped subjects’
whole-body. Video clips from the two cameras were exported into a motion analysis software
(Kinovea 0.8.15, Kinovea Org., France) and synchronised [19]. Flight time (t: ms) as counting
the number of frames from take-off to landing was first calculated. Subjects’ last foot to take-off
and the first foot to touch the ground were considered as take-off and landing, respectively.
Flight time was then inserted into the previously established formula [h = (1000 × t2) × 1.22625
/ 10000] [20] to calculate the maximal vertical jump height (h: cm). This countermovement ver-
tical jump was performed twice in the FSP; thus, a total of six jumps were averaged to represent
each time point. For the 20-m sprint, subjects were asked to run straight as fast as they could
with a standing start position (50 cm away from the start line). Two pairs of infrared timing sen-
sors (Brower Timing System, Salt Lake City, USA) were set up at the start and finish lines,
located 20-m apart. This activity was performed twice in the FSP; thus, a total of six 20-m sprint
times were averaged to represent each time point. Subjects started 50 cm away from the start
line for the Arrowhead agility test. Arrowhead agility test started towards cone-A (placed 5-m
away from the start line), moved to cone-B and cone-C, and sprinted to the finish line [21] (Fig
1). Timing systems were used as the start line and finish line to record the time taken to sprint
the agility course. This activity was performed twice in the FSP; thus, a total of six Arrowhead
agility test times were averaged to represent each time point.
To sample skin and muscle temperatures of the lower-leg, two thermistor probes, attached
as two separate channels, to the digital thermometer logger (sampling rate: 60 Hz; NT logger,
NKTC, Tokyo, Japan) were used. Each thermistor probe was attached to the gastrocnemius
medialis. Two thermistor probes (connected to each channel) were attached to the middle of
the gastrocnemius medialis muscle belly [22] in the dominant leg (the foot to kick a penalty
shootout). Channel 1 and 2 of the probes were attached into the distal 1/3 (skin) and the proxi-
mal 1/3 (muscle). The thermistor probe (channel 1) for skin temperature measurement was
secured with film dressing (Tegaderm Film, 3M, St, Paul, USA). The thermistor probe (chan-
nel 2) for the muscle temperature was covered by neoprene fabric and secured with the film
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dressing (Fig 3). This device has been validated [23] and shown high measurement reliability
with the intraclass correlation coefficient of 0.93 [24]. These data were collected four times
(before and after the first and second half: Fig 2). To record heart rate, a strap monitor (Polar
H7, Polar Electro Oy, Kempele, Finland) was worn on the subjects’ chest. Once subjects’
demographic information (sex, height, and mass) was entered, the strap was wirelessly con-
nected to a cellphone application (WearLink, sampling rate: 60 Hz). This device has been vali-
dated and shown high measurement reliability with the intraclass correlation coefficient of
0.80 to 0.86 [25]. Heart rate data in every 15-min interval (900 data points) were averaged to
represent each time point.
Statistical analysis
An a priori power analysis was performed based on the previous data about athletic perfor-
mance. An expected mean difference in maximal vertical jump of 4.3 cm with a standard devi-
ation of 6.3 cm [26] and in 20-m sprint time of 0.13 sec with a standard deviation of 0.18 sec
[27] estimated that a minimum of 17 and 14 subjects were necessary, respectively (an alpha of
0.05 and a beta of 0.2). Therefore, a sample size in this study was determined as 17.
To test the condition effects over time in athletic performance, lower-leg temperature, and
heart rate, we performed mixed model analysis of variance (random variable: subject; fixed
variable: condition and time). The least significant difference was used for post hoc pairwise
comparisons (SAS Institute Inc, Cary, USA, p<0.05 for all tests). If statistical differences
appeared, we also calculated between-time effect sizes (ES) using the formula
½ES ¼ ½X1 Fig 3. Lower-leg temperature measurements. The thermistor probes were attached to the lower-leg (Channel 1: skin
temperature, Channel 2: muscle temperature).
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Fig 4. Changes in maximal vertical jump height (A), 20-m sprint time (B), and Arrowhead agility test time (C)
over time. Values are means and the upper and lower bounds of 95% confidence intervals.  A difference between
conditions during T4 (p = 0.002, 3.08 vs. 3.17 sec, 3%, ES = 0.68).
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Fig 5A) and muscle (condition × time: F3,119 = 1.08, p = 0.36, η2 = 0.013; condition: F1,119 =
0.72, p = 0.40, η2 = 0.003; time: F3,119 = 0.20, p = 0.90, η2 = 0.002, Fig 5B) temperature of the
lower-leg.
Heart rate
The average heart rate during the whole match was recorded as 160 ± 11 bpm. We did not
observe condition effects throughout any time point on heart rate (condition × time: F5,187 =
0.31, p = 0.91, η2 = 0.003, Fig 5C). Regardless of time (condition: F1,187 = 7.09, p = 0.008, η2 =
0.013), subjects with the shuttle jog showed 2% less heart rate than those with the seated rest
(159 vs. 161 bpm, ES = 0.22). Regardless of condition (time: F5,187 = 10.05, p<0.0001, η2 =
0.086), subjects’ heart rate was lower during the initial 15-min of the second half (T4: 154
bpm), as compared with other time points (T1: 159 bpm, p = 0.003, 3%, ES = 0.48; T2: 164
bpm, p<0.0001, 6%, ES = 0.91; T3: 163 bpm, p<0.0001, 6%, ES = 0.79; T5: 160 bpm,
p = 0.0003, 4%, ES = 0.55; T6: 161 bpm, p<0.0001, 4%, ES = 0.62).
We were interested in studying the effect of a 7-min halftime shuttle jog on subsequent
lower-leg temperature and performance change in the second half as compared with a seated
rest. Our hypotheses were partly accepted as subjects who performed the halftime shuttle jog
maintained the sprint performance during the initial 15-min period of the second half when
compared with those who did the seated rest. Our data confirmed that a decremental effect of
the static rest on sprinting performance can be attenuated by a halftime warm-up. The limita-
tions from previous data such as inter-individual variability [8, 13], non-football-specific activ-
ity [10, 15], and small sample sizes [10, 12, 14, 15] have been overcome by the results of our
study. In connection with the lower-leg muscle temperature, a 3% difference in sprint perfor-
mance (3.08 vs. 3.17 sec) during T4 is reinforced by a previous suggestion that a 1˚C difference
in muscle temperature may lead to a variation of performance capacity ranged between 2%
and 5% [28, 29].
Our data on sprint performance change in both conditions during T4 has practical implica-
tions. Specifically, the difference in the speed of each performance based on the records was
calculated as 0.18 m/s (6.49 vs. 6.31 m/s), which would result in a difference in the distance
covered in a given amount of time. For example, a player with the halftime warm-up would be
approximately 0.4-m ahead of a player with the seated rest, when running 2 sec (13.0-m vs.
12.6-m). Assuming all other personal and environmental conditions are similar, this could be
the main scene of the match when considering the importance of sprinting in football.
Since > 90% of sprints were finished within 5 sec [30] and receiving a pass (travelled > 10-m)
was the most common attacking option for goal scoring [31] in actual football matches, our
estimation in sprint distance was practically meaningful.
The difference of lower-leg muscle temperature between conditions during the initial
15-min showed a 1.0˚C, which was not statistically different. Previously a higher quadriceps
muscle temperature (1.2˚C [8] and 1.0˚C [14]) after a halftime shuttle jog [8] or agility exercise
[14] was reported, as compared with the seated rest. These temperature differences led to a dif-
ference in athletic performance in which subjects with the halftime jog [8] or agility exercise
[14] ran 0.20 sec [8] or 0.10 sec faster in 30-m or 10-m sprints [14], respectively. The linear
relationship between rate of torque development and muscle temperature was also reported in
football players [32]. Based on the previous data [8, 14, 33], a muscle temperature of 1.0˚C
seems to be a sufficient amount for performance change. The measurement using the insula-
tion disk technique [34] allowed to estimate the tissue temperature at an approximate depth of
2.2 cm from the thermistor probe (Fig 3). Additionally, the lower-leg has a smaller muscle
mass and distally located than the upper leg, the whole leg temperature was probably 1.0˚C or
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Fig 5. Changes in lower-leg skin (A) and muscle (B) temperature, and heart rate (C) over time. Values are means
and the upper and lower bounds of 95% confidence intervals.
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higher in subjects who performed the halftime jog. Therefore, a 0.09 sec faster sprint time dur-
ing T4 could have been, at least partially, involved with the prevention effect of halftime jog on
the temperature reduction associated with the seated rest. While the lower-leg muscle temper-
ature for the halftime jog during T4 was recorded as 31.7˚C, we still do not know if this is an
optimal temperature for sprint performance. Either a lower or elevated muscle temperature
could impair muscle function [35], future studies should attempt to determine the ideal muscle
temperature in relation to the given environmental conditions.
Due to the intermittent nature of football, various movements are performed at different
intensities. The FSP [3] used in our study provided a similar situation of the intermittent char-
acteristics of a real football match. For example, our subjects’ sprint performance did not
decline during the last 30-min of the second half (T4 and T5) although fatigue and dehydration
could have been occurred towards to the end of match [36]. A previous report on the effects of
fatigue on football kick-related performance also showed that the ground reaction force and
joint kinematics during instep kicks were not altered by fatigue during a 90-min intermittent
exercises [37]. Additionally, a previous study reported that 70% of movements in a common
adult football match was low-intensity (e.g., jogging or walking) [38]). The distance covered by
high-intensity activities (e.g., 20-m sprint and Arrowhead agility test) in the 5-min FSP was
65-m, which is about 28% of the total distance covered (235-m) in our study. While the data
under the control condition (e.g., seated rest) in our study mimics a typical football match,
those under the halftime jog condition could, therefore, be applied to real football.
The halftime jog was not effective in preventing performance hinderance in jump height
and agility time associated with the seated rest. Contrarily, a couple of previous studies [13, 14]
reported a halftime warm-up as an effective strategy to prevent the decrements in jump perfor-
mance. The discrepancy between our results and those in previous studies [13, 14] could be
explained by the several different testing procedures, including simulation protocol (non-foot-
ball-specific [14]), measurement time point (single measurements at 46-min [13, 14] and
60-min [14]), jump height assessment techniques (force plate [14] and motion capture system
[13]), and environmental conditions (indoor laboratory [14] and 5–6˚C with 84–87% humid-
ity [13]). Additionally, the reported difference in jump heights between conditions (warm-up
vs. seated rest during halftime) was ranged between 1 [13] and 2 cm [14], which was practically
meaningless. In combination with the previous data [13, 14], our results suggest that the mag-
nitude of deterioration in athletic performance due to muscle temperature reduction may be
related to the frequency of the sport specific activities. Since running (17%) was a more fre-
quent activity than jumping (4%) in football [39], decrements in sprint performance could
have been larger than jump performance. This is indirectly supported by our data of athletic
performance during T4 that the associated 95% confidence intervals of mean difference in ver-
tical jump (Fig 6A) crosses zero while running activities (Fig 6B & 6C) does not.
Heart rate was secondarily analysed to back up any change in dependent measurements.
We observed a condition effect that subjects with the halftime jog (159 bpm) showed 2 bpm
less heart rate than subjects with the seated rest (161 bpm, ES = 0.22) in the second half. These
results in heart rate values were very similar to those in actual football matches (halftime jog:
157 bpm; seated rest: 161 bpm) [13], indicating the applicability of the FSP used in our study.
Change in the cardiopulmonary system due to training or detraining took at least 6 weeks
[40], supposing the amount of stroke volume and cardiac output in subjects in our study was
not different between the sessions. Therefore, our observation in less heart rate in subjects
with the halftime jog could be explained by circulatory efficiency [41]. Under the autonomic
regulation, the cardiovascular and hemodynamic adjustments occur to adequately deliver oxy-
gen supply to the working muscles (e.g., lower-extremity) when exercising [42]. We believe
that subjects who performed the halftime jog (average heart rate: 128 bpm) led to more active
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Fig 6. The 95% confidence intervals for difference in mean (maximal vertical jump height: A; 20-m sprint time: B;
Arrowhead agility test time: C).
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hemodynamics (e.g., exchanging nutrients and wastes) in the lower-extremity when compared
with players who did the seated rest. Since the same workloads (the 5-min FSP ×9) to both
conditions were given, the lower-extremity with a worse circulatory efficiency (e.g., seated rest
condition) required a continuous blood supply to accommodate for the energy requirements.
As a result, subjects with the halftime jog showed less heart rate.
Our study has several limitations. First, the data were collected under the environmental
conditions (air temperature: 17.5˚C, relative humidity 40%, and pitch condition: natural grass)
on a specific population (collegiate male footballers with an athletic career of 10 years), which
should be considered when generalising the results. In connection with the weather condition,
a difference in core temperature between conditions should have certainly had an impact on
athletic performance [43]. It should also be noted that the jog intensity was guided by the
research assistant, not self-determined by the player. In case of under- or over-pacing, we rec-
ommend coaches and players practice getting used to the optimal intensity of the halftime jog.
Conclusions
Our data demonstrated potential benefits of 7-min halftime jog on sprint performance during
the initial 15-min of the second half. Our results are meaningful that the limitations of the cur-
rent existing data [8, 10, 12–15] have been overcome by obtaining data from a 90-min simu-
lated football match performed by a larger number of footballers. We recommend performing
a moderate-intensity aerobic exercise (70% of the maximum heart rate) during halftime to
avoid the negative effects associated with the sedentary halftime period.
Supporting information
S1 Data.
(XLSX)
Author Contributions
Conceptualization: Jihong Park.
Data curation: Sooil Bang.
Formal analysis: Jihong Park.
Investigation: Jihong Park.
Methodology: Sooil Bang, Jihong Park.
Supervision: Jihong Park.
Visualization: Sooil Bang, Jihong Park.
Writing – original draft: Sooil Bang, Jihong Park.
Writing – review & editing: Sooil Bang, Jihong Park.
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A halftime jog on athletic performance and lower-leg temperature in a simulated football match
PLOS ONE | https://doi.org/10.1371/journal.pone.0270898
July 19, 2022
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A 7-min halftime jog mitigated the reduction in sprint performance for the initial 15-min of the second half in a simulated football match.
Bang, Sooil,Park, Jihong