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The athletic advantage of sleep, although commonly touted by coaches, trainers, and sports physicians, is still unclear and likely varies by sport, athletic performance metric, and length of sufficient or insufficient sleep. Although recent literature reviews have highlighted circadian and nutritional factors that influence different aspects of athletic performance, a systematic summary of the effects of sleep duration and sleep quality on performance among competitive athletes is lacking. Here we systematically review the relationship between sleep duration and sleep quality and objective athletic performance among competitive athletes across 19 studies representing 12 sports. Taken holistically, we find that the sports requiring speed, tactical strategy, and technical skill are most sensitive to sleep duration manipulations. Furthermore, longer-term sleep manipulations are more likely than acute sleep manipulations (whether deprivation or extension) to affect athletic performance. Thus, the importance of sleep for competitive athletes to achieve high performance is dependent on the demands of the sport as well as the length of sleep interventions. In light of the limited number of studies investigating sleep quality and performance, the potential relevance of subjective sleep quality remains an interesting question for future work.
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Critical Review
The Impact of Sleep Duration on Performance
Among Competitive Athletes: A Systematic
Literature Review
Gregory W. Kirschen, PhD,*† Jason J. Jones, PhD,†‡ and Lauren Hale, PhD†§
Abstract: The athletic advantage of sleep, although commonly touted by coaches, trainers, and sports physicians, is still unclear
and likely varies by sport, athletic performance metric, and length of sufficient or insufficient sleep. Although recent literature reviews
have highlighted circadian and nutritional factors that influence different aspects of athletic performance, a systematic summary of
the effects of sleep duration and sleep quality on performance among competitive athletesis lacking. Here we systematically review
the relationship between sleep duration and sleep quality and objective athletic performance among competitive athletes across 19
studies representing 12 sports. Taken holistically, we find that the sports requiring speed, tactical strategy, and technical skill are
most sensitive to sleep duration manipulations. Furthermore, longer-term sleep manipulations are more likely than acute sleep
manipulations (whether deprivation or extension) to affect athletic performance. Thus, the importance of sleep for competitive
athletes to achieve high performance is dependent on the demands of the sport as well as the length of sleep interventions. In light of
the limited number of studies investigating sleep quality and performance, the potential relevance of subjective sleep quality remains
an interesting question for future work.
Key Words: athletic performance, aerobic, anaerobic, strength, tactical, technical, sleep quality, sleep duration
(Clin J Sport Med 2018;0:1–10)
INTRODUCTION
High-quality, sufficient sleep is often presumed to be necessary
for multiple factors contributing to sports performance, such
as promoting physical and mental recovery from rigorous
training regimens, minimizing the risk of injury, and prevent-
ing in-game fatigue and lapses in concentration. Indeed,
coaches, trainers, and physicians all emphasize the importance
of good sleep hygiene for athletes, especially in the days and
nights leading up to competition.
14
Significant efforts have
been underway to better understand and characterize rest and
functional recovery among athletes,
57
with the implicit goal
of helping athletes optimize their performance. Outside of the
sports science community, 2 separate sleep time duration
consensus panels have recently advised that young adults and
adults
8,9
get at least 7 hours of sleep per night. However,
specific guidelines for competitive athletes do not exist. The
definition of adequate high-quality sleep and the validity of the
long-held precept that sleep is essential for peak athletic
performance have not been systematically verified via review
of the relevant literature.
Several recent literature reviews have assessed the science
on sleep and athletic performance. One of these reviews
investigated the effects of circadian disruptions, sleep distur-
bance, and diurnal variation in sports performance. This
review article confirmed that circadian disruptions and sleep
disturbance alter sports performance, but results were mixed
based on specific skill sets tested and methodologies
employed.
10
Another focused on the physiological interplay
between physical performance, exercise, and sleep.
11
Yet
another highlighted nutritional interventions that could be
used to improve sleep among athletes to maximize perfor-
mance.
12
The physiological, emotional, and cognitive ram-
ifications of reduced sleep in athletes can also be considerable,
especially when sleep deprivation is prolonged.
13
In general, these studies indicate that sleep extension tends
to improve athletic performance, whereas total sleep depriva-
tion (24-hour) and partial sleep deprivation (less than one
night) tend to impair performance, although anaerobic or
explosive muscle power performance seems less sensitive to
sleep deprivation than does aerobic or endurance perfor-
mance.
10
With respect to diurnal variations in performance,
peak performance is often observed in the evening across
various sports, and the effects of circadian misalignment on
performance are exacerbated when traveling eastward,
thereby temporally shifting ones environment forward.
10
Regular exercise, particularly in the evening and nighttime,
has been shown to improve sleep quality among healthy non-
athlete adults, challenging the conventional idea that exercise
in the evening is detrimental to optimal sleep hygiene.
11
On the
other hand, exercise can cause increased nocturnal heart rate
Submitted for publication September 25, 2017; accepted April 29, 2018.
From the *Medical Scientist Training Program, Stony Brook Medicine, Stony Brook,
New York;
Stony Brook University, Stony Brook, New York;
Department of
Sociology; and
§
Department of Family, Population and Preventive Medicine, Stony
Brook Medicine; Program in Public Health, Stony Brook, New York.
L. Hale currently receives partial salary support from the Eunice Kennedy Shriver
National Institute for Child Health and Human Development (NIH R01 HD 073352)
and the National Heart, Lung, and Blood Institute (R01 HL 122460). She also sits on
the Board of Directors for the National Sleep Foundation and Sleep, Inc, and
receives an honorarium from the National Sleep Foundation for her role as Editor-in-
Chief of Sleep Health.
The authors report no conflicts of interest.
Corresponding Author: Gregory W. Kirschen, PhD, Medical Scientist Training
Program (MSTP), Stony Brook University School of Medicine, Stony Brook
University, Stony Brook, NY 11794-8338, Gregory.kirschen@stonybrookmedicine.
edu.
Copyright ©2018 Wolters Kluwer Health, Inc. All rights reserved.
http://dx.doi.org/10.1097/JSM.0000000000000622
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variability and maintain sympathetic autonomic tone that
normally dampens at night.
14
Many professional athletes not
only exhibit low total sleep duration (,7 hours/night), but
also report lower sleep quality (eg, increased nighttime
awakenings, lower sleep efficiency), especially after night
matches, and even after home games.
1519
The effects of
increased exercise and especially night exercise on functional
recovery and subsequent performance among athletes remain
unclear, however.
From a physiological perspective, sleep has been shown to
aid in restoration of immune function and muscle and
cartilage repair following strenuous exercise and physical
stress/strain. For example, as exercise regimens increase in
volume and vigor, the risk of upper respiratory tract infections
increases, an effect that is exacerbated by sleep
deprivation.
2022
Mechanistically, natural killer cell activity,
which aids the hosts response to viral pathogens, decreases
with loss of total sleep time and decreased sleep efficiency,
whereas cytokines such as interleukin-6 (IL-6; involved in
mounting a lymphocytic response to pathogens) are depressed
in subjects experiencing at least partial sleep deprivation.
2325
This may help explain the enhanced susceptibility to infection
in the setting of sleep deprivation. Likewise, sleep deprivation
has been shown to dysregulate normal circadian fluctuations
in the catabolic hormone cortisol and the anabolic hormones
growth hormone, and testosterone, which may lead to delays
in repair of articular cartilage and muscle, thus impairing
functional recovery.
11,26
Furthermore, sleep deprivation
impedes replenishment of muscle glycogen stores following
exercise, compromising the energy supply for both repair of
myofibrillar micro-damage and subsequent contractile
use.
27,28
Sleep deprivation can also impair glucose metabolism,
increasing ones risk of developing obesity and type II diabetes
mellitus, whereas caloric restriction or diets high in fat can
disrupt sleep architecture.
12
Meanwhile, diets rich in trypto-
phan, large neutral amino acids, and the nucleotides uridine
monophosphate and adenosine monophosphate improve
various sleep indices and also promote muscle repair and
recovery as well as immune function following
exercise.
12,2932
Importantly, however, none of the aforementioned studies
focused specifically on sleep duration as a predictor of athletic
outcomes among competition-level athletes. Given the high
level of training and exercise endured by athletes engaged in
relatively high-stakes events (compared to the average
recreational player), the consequences of sleep duration and
quality on their practice and performance are particularly
important. Furthermore, specific effects on sports requiring
varying skills, such as those incorporating tactics and
decision-making, highly technical skills, strength, or endur-
ance, have not been well parsed. Finally, rigorous experimen-
tal studies have contributed to key insights into the question of
whether and how sleep and performance interact in high-level
competitive athletes.
15,3340
With the professional sports
industry in North America valued in the multi-billion dollar
range,
41
the question of how sleep duration impacts sports
performance carries considerable financial, apart from
academic, as well as scientific interest. The present work is
novel in that it systematically reviews the relationship between
sleep quantity/quality among competition-level athletes and
objective performance outcomes. Further, we identify differ-
ences in methodologies and measurement, including an
assessment of the various types of athletic outcomes consid-
ered (eg, aerobic, tactical, technical, and strength).
METHODS
We conducted a systematic literature search in PubMed for
original scientific research publications related to sleep
duration and objective performance outcomes among com-
petitive athletes. The following terms were used for searches
conducted between July and August 2016, with follow-up
searches during February 2017: sleep AND (athletes OR
athletics) AND performance,”“sleep deprivation AND
athletes,”“sleep AND performance AND elite (athletes OR
athletics),”“sleep AND elite athletics,”“sleep AND pro-
fessional (athletes OR athletics),”“sleep extension AND
(athlete OR athletics) AND performance,and sleep
extension AND athletes.These searches returned 907
articles.
We then reviewed all of the abstracts and used the following
inclusion criteria to refine our article selection: At least one
sleep quantity or quality metric and at least one objective
performance metric must have been included. Studies must
have been conducted with competitive (professional, elite, or
competition-level, but not recreational) athlete participants of
all ages. Sleep duration must have been measured the night
before the performance outcome. We included studies of both
team and individual sports. We used the following exclusion
criteria: Studies should not have been conducted with non-
athletes (eg, military, firefighters, healthy sedentary or recrea-
tionally active volunteers), or those with injury or pathology
present (eg, concussion and heat-related illness), or under non-
physiological or extreme environmental conditions (eg,
alcohol consumption, fasting, and high altitude). We further
excluded studies in which the only performance metric used
was self-reported self-evaluation of performance. We ex-
cluded studies not written in English or translated into
English. We included both experimental and observational
studies with or without control conditions. Finally, we
consulted an expert in the field (R.D.) to review the list of
included studies and suggest others relevant to the current
review. See Figure 1 for a flow diagram of the articles included.
In total, we identified 20 studies that conformed to
inclusion and exclusion criteria. After this screen, one study
was further excluded because the outcome depended on 2
player performance. Among the remaining 19 studies, 15 were
experimental and 4 were observational. Sports included
soccer, basketball, tennis, marathon and ultra-marathon
running, cycling, swimming, triathlon, rugby, weightlifting,
judo, taekwondo, karate, and gymnastics.
RESULTS
Table 1 describes all studies that met our inclusion criteria. Of
note, objective performance outcomes varied among the
studies, ranging from sport-specific performance to general
athletic performance. Athletic performance outcomes that
have been independently validated and shown to be reliable
indicators of the intended metric are indicated with an
asterisk.
4248
For sports that included in their performance assessments
at least one predominantly aerobic or one predominantly
anaerobic outcome (eg, endurance exercise or muscle
G.W. Kirschen et al. (2018) Clin J Sport Med
2
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strength/power, respectively), we classified the results of the
studies as either positive (1), negative (2), or null (0) in
Table 2. We defined positive results as those in which sleep
was positively associated with performance (ie, greater
sleep quantity and improved performance, or vice versa),
negative results as those showing the inverse association,
and null results showing no association. To provide more
precise information beyond the valence of the association,
we also included the specific effect and magnitude of the
effect for studies that found statistically significant effects
and provided such information (Table 2). Among 13 such
studies, we found that 9 reported positive
associations,
22,3436,38,40,4952
0reportednegativeassoci-
ations, and 4 reported null results.
15,17,33,53
Outofthe8
studies that measured purely anaerobic outcomes, 6 were
positive and 2 were null. Out of the 3 studies that measured
purely aerobic outcomes, 2 were positive and 1 was null. Of
those that measured composites scores incorporating both
aerobic and anaerobic components, 1 was positive and 1
was null. We further categorized these studies by whether
they included a strength-based outcome, eg, weightlifting
capacity (Table 2). Of the 3 studies, 2 were positive for these
strength-based outcomes and 1 was null. Of the 6 studies
that included speed-based outcomes, 5 were positive for
these speed-based outcomes, whereas 1 was null. Among
those that included both strength-based and speed-based
outcomes, 2 were positive and 2 were null.
We next compared studies in which a tactical or
technical/motor coordination-based outcome was mea-
sured (Table 3). We defined tactical outcomes as those
requiring strategy, teamwork, or decision-making, and we
defined technical/motor coordination-based outcomes as
those requiring fine motor skills, such as tennis serving or
basketball shooting, or physical coordination such as
passing balls or performing gymnastic movements. Out of
6 such studies, 1 included at least one tactical outcome
54
and all 6 included at least one technical/motor
coordination-based outcome.
34,35,3739,54
We again classi-
fied these studies as positive, negative, or null and included
the specific effect and magnitude where applicable, as
described above. Strikingly,wefoundthatall6studies
reported positive associations between sleep duration and
performance (Table 3).
Finally, we grouped experimental studies according to
whether the sleep interventions were acute (defined as less
than or equal to 48 hours) or longer term (defined as greater
than or equal to 1 week), which also varied in terms of
whether they involved sleep deprivation or extension. We
Figure 1. Flow diagram of literature review.
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TABLE 1. Characteristics of Included Studies
Study Sport Study Design Sample Size
Measure of Sleep
Duration
Measure of Sleep
Quality
Objective Performance
Outcome(s)
*Ben
Cheikh
52tbl1fnlowast
Karate Experimental,
within-subjects
design
12 karate athletes 24 h TSD N/A Maximal isometric force
production of biceps
brachii muscle
*Blumert
33
Weightlifting RCT 9 national
competitive
weightlifters
Sleep diary—recall of
duration
Sleep diary Snatch, clean and jerk,
front squat weight lifted
(kg)
Baseline night (mean 8
hours sleep) vs 24 h TSD
*Cook
36
Rugby RCT 16 professional
rugby players
Sleep diary for total sleep
duration (2 conditions—8
hor,6h)
REST-Q Bench press, squat, bent
row. Measured voluntarily
chosen workload 5#
repetitions * load (kg)
Cook
34
Rugby RCT 10 professional
rugby players
Sleep diary; subjects
instructed to sleep either
7-9 h or 3-5 h
N/A Rugby passing skill test
Duffield
38
Tennis Experimental,
within subjects
8 highly trained
tennis players
Sleep diary for minutes in
bed, 24 h TSD,
N/A Total, forehand, and
backhand stroke counts,
forced and unforced
errors, time in match
play, stroke rate per min
and player load, sum of
triaxial accelerometry
*Fullagar
15
Soccer RCT 20 semi-
professional soccer
players
Actigraphy to measure
night sleep and naps
(means TD: 8:44 sleep 1
0:57 nap, DM: 8:20 sleep
10:30 nap, NM: 5:43
sleep 11:17 nap)
Sleep restfulness (scale
from 1 to 5)
Jump height, force
production, Yo-Yo
intermittent recovery test,
submaximal intermittent
running test
Hausswirth
22
Triathlon Experimental 40 trained
triathletes
Wrist actigraphy to
measure sleep duration
(functionally overreached:
7:09 at baseline; 6:36
3rd wk overload)
Perceived sleep quality,
sleep efficiency, and
fragmentation index
Workload on cycle
ergometer (watts)
Lastella
17
Distance running Observational 103 marathon
runners
Survey-reported amount
of sleep precompetition
night (average: 6:38
sleep)
Sleep quality from 23to
13 relative to a “usual
night”
Relative performance,
defined as difference
between expected and
actual performance time
expressed as
a percentage
eger
54
Sailing Observational 8 elite sailing
racers
Polysomnography or
electro-oculography to
measure sleep night
before each leg of race
(total sleep time 93.2 min
in leg 1 and 155 min in
leg 2)
PSQI, Spiegel Sleep
Index, Epworth
Sleepiness Scale,
polysomnography or
electro-oculography to
measure REM vs non-
REM before each leg of
race
Ranking in race
*Mah
35
Basketball Experimental,
within subjects
11 varsity
basketball players
2-4 wk baseline (mean
7.8 h/night) followed by
5-7 week extension
(mean 10.4 h/night)
N/A Free throw shooting
accuracy, timed sprint,
and reaction time test
*Mah
49
Swimming Experimental,
within subjects
5 varsity swimmers Actigraphy, sleep diary. 2
wk baseline “usual sleep”
followed by extension to
10 h/night for 6-7 wk.
Epworth Sleepiness Scale 15 m sprint, reaction
time, turn time, and kick
strokes
*Mejri
40
Taekwondo Experimental,
within subjects
10 national
taekwondo
competitors
Reference
night—participants slept
;7 h. PSD: 3 or 4 hours
of SD.
N/A Yo-Yo intermittent
recovery test
G.W. Kirschen et al. (2018) Clin J Sport Med
4
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found that 7/10 acute sleep manipulation studies yielded
positive results, whereas 4/4 longer-term sleep manipula-
tion studies yielded positive results (Table 4). We further
sub-classified these experimental studies as either sleep
extension (defined as enhancing sleep quantity) or sleep
deprivation (defined as diminishing sleep quantity). Among
the 10 acute intervention studies, 2 involved sleep exten-
sion, while 8 involved sleep deprivation. One acute sleep
extension study was positive, whereas the other was null,
and 6/8 deprivation studies were positive. Among the 4
chronic sleep intervention studies, 2 involved extension and
2 involved deprivation, and all 4 found positive effects of
sleep duration on performance.
We were finally curious to determine whether subjective
sleep quality would be associated with performance.
Among the 20 included studies, 7 recorded measures of
sleep quality, ranging from validated sleep quality scales to
sleep diary entries.
15,17,22,33,36,49,55
Of these studies, 3
observed positive associations between sleep quality and
performance,
22,49,55
2 observed no association,
15,17
whereas the rest did not attempt to use the measure of
sleep quality to predict performance.
DISCUSSION
This literature review, although diverse in the range of sports,
methods, and outcomes studied, provides several stylized facts
that can inform sleep research and competitive athletes. First,
out of all the published studies we reviewed, none found
a negative association between sleep duration and any
performance outcome. All of the results reviewed showed
that either the increased sleep duration has a positive effect on
athletic performance or the results were neutral. Note that
among studies reporting significant positive results, effect sizes
varied considerably (Tables 2-4), likely due to differences in
the duration of sleep deprivation/extension experienced as
well as differences in outcome measures.
Second, when considering the aerobic and anaerobic
characteristics of sports, it seems that aerobic activity is
more sensitive to sleep duration compared to anaerobic
activity, including strength testing. For instance, Mejri
et al
40
found that depriving competitive taekwondo boxers
of a mere 3 to 4 hours of sleep significantly impaired
performance on the Yo-Yo intermittent recovery test. By
contrast, Blumert et al
33
employed a relatively severe sleep
TABLE 1. Characteristics of Included Studies (Continued)
Study Sport Study Design Sample Size
Measure of Sleep
Duration
Measure of Sleep
Quality
Objective Performance
Outcome(s)
*Mougin
53
Unspecified highly
trained athletes
Experimental 8 highly trained
athletes
Self-reported delayed
bedtime until 3 AM
N/A 30 s Wingate test
*Reyner
37
Tennis RCT 16 varsity level
tennis players
Actigraphy, reference
night 6.67 hours sleep vs
2-2.5 h PSD
N/A Serving accuracy
*Schwartz
39
Tennis Experimental,
within subjects
12 varsity tennis
players
Sleep diary—recorded
hours per night; after
baseline and then asked
to extend sleep by 2 h/
night for 1 wk.
N/A Serving accuracy
Silva
56
Gymnastics Observational 67 elite gymnasts Subjective recall of
duration (highest scoring:
8:30, 8:32 and lowest
scoring: 7:41, 8:27 on
weekdays and weekends,
respectively
ESS; PSQI Performance rank in
competition
*Skein
69
Rugby RCT 11 amateur rugby
league players
Global positioning system
(GPS) device worn as
cervical harness. 8 hours
sleep (control) vs 24 h
TSD
N/A Countermovement jump
(CMJ) distance, knee-
extensor maximal
voluntary contraction
(MVC), and voluntary
activation (VA)
*Souissi
50
Judo Experimental,
within-subjects
12 competitive
judokas
Laboratory-monitored
baseline (7:30 sleep) vs 4
h sleep deprivation (slept
in laboratory)
N/A Handgrip strength,
maximal voluntary
contraction, and Wingate
test
Staunton
55
Basketball Prospective cohort
design
17 elite basketball
players
Triaxial accelerometers to
measure total sleep
duration (TST: 8.2 h
double-header; 7.1 h
baseline; 7.3 h match
day)
N/A Basketball efficiency
statistic 5(Points 1
Rebounds 1assists 1
steals 1blocks) 2
(missed field goals 1
missed free throws 1
turnovers)
*SD5sleep deprivation.
DM, day matches; NM, night matches; PSD, partial sleep deprivation; PSQI, Pittsburgh Sleep Quality Index; RCT, randomized controlled trial; REST-Q, Recovery-Stress Questionnaire; TD,
training days; TSD, total sleep deprivation.
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deprivation protocol by depriving 9 national-caliber
collegiate weightlifters of 24 hours of sleep and yet failed
to identify adverse effects on any of the various weightlift-
ing exercises examined. Relatedly, for both endurance and
explosive, power-based exercises, it has been well docu-
mented that sleep deprivation is associated with increased
perceived effort.
5658
Still, the relationship between per-
ceived effort and objective performance has not been widely
validated and is a topic for future investigation.
Third, of the studies that measured outcomes requiring
either tactical and/or technical skills, most find benefits of
sleep on performance. Tennis serving accuracy and basketball
shooting were both improved by long-term sleep extension
interventions,
35,39
and tennis serving accuracy suffered when
players were deprived of 2 to 2.5 hours of sleep at the
beginning of the preceding night.
37
Regarding studies
conducted in players of team sports that incorporated tactics
and decision-based outcomes to a broader extent, soccer as
well as rugby players exhibited performance deficits after
nights of decreased sleep duration.
34
These results are in line
with other literature demonstrating clear neurocognitive
deficits in the setting of inadequate sleep in the general
population, reviewed thoroughly elsewhere.
59,60
Finally, when looking at the methodologies of the
experimental studies, we found that the studies that altered
sleep duration on a longer-term timescale were more likely to
show an effect than those that altered sleep duration acutely.
Interestingly although most acute sleep interventions involved
sleep deprivation and yielded positive results, there were
inconsistent results among the 2 acute sleep extension
studies.
15,38
Conversely, the majority of longer-term sleep
intervention studies involved sleep extension and showed
positive results.
35,39,49
Taken together, these findings suggest
that on a short timescale, sleep deprivation may be more
harmful than sleep extension is beneficial to performance,
although in the longer term, sleep extension may contribute to
improved performance. On the other hand, more research is
warranted regarding potential adverse effects of chronic sleep
loss on athletic performance.
The reliability and precision of the various measurements
may present challenges in interpretation of these studies. For
example, maximalvoluntary muscle contraction and
voluntarily chosen training load are variable across sub-
jects.
61,62
On the other hand, running economy,the oxygen
cost associated with a given running velocity, has low
variability among highly trained runners and is significantly
TABLE 2. Summary of Studies Measuring Anaerobic versus Aerobic Outcomes
Author Sport
Aerobic or Anaerobic
Outcome?
Strength- or Speed-Based
Outcome?
Valence of Finding
(1,2, 0) Effect and Magnitude*
Ben
Cheikh
52
Karate Anaerobic Strength 1More sleep 15% longer time
engaging biceps brachii in maximum
force
Blumert
33
Weightlifting Anaerobic Strength 0 N/A
Cook
36
Rugby Anaerobic Strength 1More sleep increased total workload
(effect size: 2.33)
Duffield
38
Tennis Both Speed 1More sleep increased time in play
and stroke rate (effect sizes: .0.9)
Fullagar
15
Soccer Both Both 0 N/A
Hausswirth
22
Triathlon Anaerobic Both 1More sleep increased power on
ergometer (110 W)
Lastella
17
Distance
running
Aerobic Speed 0 N/A
Poussel
51
Distance
running
Aerobic Speed 1Data not presented
Mah
35
Basketball Anaerobic Speed 1More sleep 9% increase in free
throw accuracy, 9.2% increase in 3-
point field goal percentage
Mah
49
Swimming Aerobic Speed 1More sleep 7% faster sprint; 17%
faster reaction time; 9% faster turn
time
Mejri
40
Taekwondo Anaerobic Speed 1More sleep approximately 25%
increase in Yo-Yo intermittent recovery
test distance†
Mougin
53
Unspecified Anaerobic Both 0 N/A
Souissi
50
Judo Anaerobic Both 1More sleep 3.1-8.4 kg increased
handgrip strength; 15%-24%
increased maximum voluntary
contraction; 3.9%-9.0% increased
peak power on Wingate; 2.6%-6.6%
increased mean power on Wingate
* Due to different sleep deprivation/extension study designs and outcome measures, magnitudes across studies are not comparable. Refer to individual studies for more details.
† Precise data were not available. Results in Figure 1A.
G.W. Kirschen et al. (2018) Clin J Sport Med
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correlated with cardiorespiratory parameters used to assess
aerobic capacity.
63
A meta-analysis of the reliability of various
measures of muscle power previously identified that field
running tests tended to be more reliable than treadmill
running tests, tests lasting up to 1 minute tended to be more
reliable than those lasting greater than 1 minute (likely due to
increased variability in muscle movement and limb position-
ing), and isokinetic tests tended to be more reliable when
measuring muscle extension versus flexion.
62
Somewhat
reassuringly in the context of the present review, this meta-
analysis also found that measurements taken from athletes
were more reliable than those taken from non-athlete subjects.
With respect to the validity of outcome measures reported
as performance indicators, the nature of the sport (eg, team vs
individual) may be an important determinant of whether what
is measured in the laboratory translates to the actual game.
For instance, for team-based sports requiring complex game
structure such as soccer, measures of muscle force production
or running speed are likely insufficient to provide an accurate
assessment of in-game performance, although they may be
helpful in making gross approximations and predictions.
64
Of
course, actual performance metrics from real or simulated
games would be the ideal outcomes to quantify for such sports
in future investigations. More specifically, for performance
outcomes included in the current review, the following have
been independently validated and shown to be reliable
measures of athletic performance: Yo-Yo intermittent re-
covery (YYIR) test, isometric muscle contraction, squat,
countermovement jump, free sthrow basketball shooting,
tennis serving, shuttle-running tests, and Wingate test.
4248
In
Table 1, we have indicated studies employing previously
validated and reliable metrics of objective performance with
asterisks (as per the criteria discussed above). Still, more work
will be required to further validate the various performance
outcomes measured in the studies reviewed in the present
work, especially those involving complex, team-based meas-
ures such as composite game performance scores and passing
accuracy. Likewise, given the high inter-individual variability
of sleep variables used across the included studies, these
metrics will also require further investigation to determine
their precision and reliability as predictors of athletic
performance.
Importantly, we chose to require at least one objective
performance measure among our inclusion criteria. The
previous work relying on self-perceived performance, al-
though informative in understanding the potential effect of
sleep loss or gain on sports psychology,
15
may not accurately
reflect actual performance, as was the goal of the present
work. However, under certain circumstances, self-perceived
pre-game wellness (including self-reported sleep quality) may
be predictive of objective in-game performance.
65
More
research will be needed to assess the validity of player-
reported performance and objective performance, especially
when athletes exhibit compromised sleep.
Several experimental studies are particularly illustrative of
the various trends in the results we have just outlined. To
address the question of whether one night of sleep extension
would be sufficient to improve various fitness indices among
semi-professional soccer players, Fullagar et al
15
tested a sleep
hygiene intervention. The investigators implemented a sleep
hygiene strategy (SHS) designed to maximize sleep duration
and limit stimulation before bedtime to test whether this
would be sufficient to improve either anaerobic (jumping
height and force production) or aerobic endurance (YoYo
intermittent recovery level 2, YYIR2) performance after late-
night soccer matches. Implementing a randomized design,
they assigned 20 participants to follow either their normal
post-match sleep routine [non-SHS (NSHS)] or a SHS in-
volving early dimming of lights and lights out by midnight,
cool room temperature, and no technology or light stimula-
tion for 15 to 30 minutes before bedtime. Actigraphy was used
to measure sleep patterns, and sleep diary was used for
subjective recall of sleep quality. Despite finding that those
assigned to the SHS indeed exhibited increased sleep duration
after the night match relative to those in the NSHS group, the
investigators failed to identify any improvements in
TABLE 3. Summary of Studies Measuring Tactical or Technical Outcomes
Study Sport
Tactical
Outcome?
Technical/Motor Coordination-Based
Outcome? Finding (1,2, 0) Effect and Magnitude*
Cook
34
Rugby None Yes 1More sleep increased mean passing
accuracy of approximately 20% on dominant
and non-dominant sides†
Duffield
38
Tennis None Yes 1More sleep increased time in play and stroke
rate (effect size: .0.9)
Mah
35
Basketball None Yes 1More sleep 9% increase in free throw
accuracy, 9.2% increase in 3-point field goal
percentage
Reyner
37
Tennis None Yes 1More sleep approximately 20%-30%
increase in serving accuracy‡
Schwartz
39
Tennis None Yes 1More sleep increased serving accuracy out
of 50 (deuce and add side together): after sleep
extension: 17% improvement vs before sleep
extension
Staunton
55
Basketball Yes Yes 1More sleep improved basketball efficiency
statistic (r 50.39 — 0.22 range)
* Due to different sleep deprivation/extension study designs and outcome measures, magnitudes across studies are not comparable. Refer to individual studies for more details.
† Precise data were not available. Results in Figure 1.
‡ Precise data were not available. Results in Figure 1B.
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countermovement jump height, countermovement jump force
production, or YYIR2 performance, tested over the following
2 days.
On the other hand, as we have discussed, studies of acute
sleep deprivation, especially those measuring technical per-
formance outcomes, tended to yield positive results. Given
that sleep is often disrupted the night before athletic
competition,
66
athletes involved in sports requiring these
types of skills are likely to be particularly sensitive to sleep
manipulations and thus should be counseled regarding the
importance of sleep for game performance. Relatedly, chronic
sleep extension studies have demonstrated significant benefits
to athletes.
35,49
Thus, strategies to improve sleep not only the
night before an important sports event but also in the weeks
leading up to this event are likely to be fruitful in improving
performance.
In this review, we have summarized and synthesized recent
findings in the realm of sports and sleep science. One of the
challenges of conducting such a literature review is that the
study methodologies vary a great deal, as do the individual
sports, making comparisons of effects and magnitudes of
effect sizes across studies difficult. Additionally, unlike many
studies of athletic performance and sleep conducted in non-
athletes and recreational sports players, studies incorporating
high-level competitors are limited, especially those implement-
ing experimental approaches. Even among the best-controlled
studies, sample sizes are small and sleep measurements vary
considerably, with some studies measuring sleep duration
objectively through polysomnography or actigraphy and
others relying on self-report. All of these factors limit the
scope of the conclusions that can be drawn. Nevertheless, they
do provide valuable information about when sleep does or
TABLE 4. Summary of Experimental Study Findings
Author Sport
Acute or Longer-Term Sleep
Intervention?
Sleep Extension or
Deprivation?
Finding
(1,2, 0) Effect and Magnitude*
Ben
Cheikh
52
Karate Acute Deprivation 1More sleep 15% longer time
engaging biceps brachii in maximum
force
Blumert
33
Weightlifting Acute Deprivation 0 N/A
Cook
36
Rugby Acute Deprivation 1More sleep increased total workload
(effect size: 2.33)
Cook
34
Rugby Acute Deprivation 1More sleep increased mean passing
accuracy of approximately 20% on
dominant and non-dominant sides†
Duffield
38
Tennis Acute Extension 1Increased time in play and stroke rate in
intervention vs control (effect size:
.0.9)
Fullagar
15
Soccer Acute Extension 0 N/A
Hausswirth
22
Triathlon Longer term Deprivation 1Decreased power on ergometer (210 W
vs control)
Mah
35
Basketball Longer term Extension 19% increase in free throw accuracy,
9.2% increase in 3-point field goal
percentage in sleep extension group vs
control
Mah
49
Swimming Longer term Extension 1Faster sprint (sleep extension group:
93% vs control); faster reaction time
(sleep extension group: 83% vs control);
faster turn time (sleep extension group:
91% vs control)
Mejri
40
Taekwondo Acute Deprivation 1More sleep approximately 25%
increase in Yo-Yo intermittent recovery
test distance‡
Mougin
53
Unspecified Acute Deprivation 0 N/A
Schwartz
39
Tennis Longer term Extension 1Increased serving accuracy out of 50
(deuce and add side together): after
sleep extension: 117% improvement vs
before sleep extension
Skein
69
Rugby Acute Deprivation 1Slower sprint time with sleep deprivation
(sleep deprivation day 2: 2.78 sec vs
control day 2: 2.74 sec)
Reyner
37
Tennis Acute Deprivation 1More sleep approximately 20%-30%
increase in serving accuracy§
Due to different sleep deprivation/extension study designs and outcome measures, magnitudes across studies are not comparable. Refer to individual studies for more details.
† Precise data were not available. Results in Figure 1 of Cook
34
.
‡ Precise data were not available. Results in Figure 1A of Mejri
40
.
§ Precise data were not available. Results in Figure 1B of Reyner
37
.
G.W. Kirschen et al. (2018) Clin J Sport Med
8
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particularly when sleep does not seem to play a key role in
influencing performance. Future research may seek to use
larger sample sizes and standardize tests of athletic perfor-
mance in order to identify optimal sleep standards, in addition
to standardizing sleep metrics and incorporating more
objective sleep data. In particular, here we focused on studies
investigating sleep duration, although sleep timing is likely to
be a relevant factor as well. As sleep onset and wake time have
previously been shown to influence performance and re-
covery,
5
future studies should aim to incorporate this
information.
Given these suggestions for improving future research,
there are many opportunities for innovative research on this
topic. One area in particular may be about how generalizable
these findings are to other sports. Given the wide range of
methodologies and used in these studies, another research goal
would be to harmonize measures across studies and conduct
a meta-analysis. Another area to investigate is trade-offs
between wake time activities (eg, athletic practice) and sleep.
For example, is it beneficial for swimmers to practice early in
the morning even at the expense of their sleep? Research also
should seek to investigate the mechanisms by which aerobic,
tactical, and technical performance attributes may be prefer-
entially sensitive to changes in sleep patterns.
One limitation of the present work is that although the
number of hours and/or nights of sleep interventions across
studies varied, sleep duration was only measured the night
before performance assessment. Thus, in order to obtain
a more complete picture of sleep quantity and quality, future
research should aim to measure sleep across the entire study
period. Another limitation is that few of the studies examined
explicitly the relationship between subjective sleep quality and
performance, especially using validated sleep quality ques-
tionnaires such as the PSQI and ESS. Thus, this remains an
open question that will be important to be investigated in the
future. Once all these data are gathered, feasible and effective
interventions should be developed, implemented, and evalu-
ated to improve the sleep health and optimal performance of
athletes.
In conclusion, the importance of sleep for professional
athletes to achieve high performance varies by the cognitive
and physical demands of the sport. However, because most
sports require integration of aerobic fitness, tactical skills, and
technical skills, competitive athletes will likely benefit from an
increase in sleep duration.
ACKNOWLEDGMENTS
The authors would like to thank Dr Rob Duffield for his
review of the included articles reviewed in this manuscript.
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G.W. Kirschen et al. (2018) Clin J Sport Med
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... Clearly, laboratory studies have been demonstrating that sleep extension and restriction affects athletic performance among collegiate players. And systematic review also had determined that the sports requiring speed, tactical strategy, and technical skill were the most sensitive to sleep duration manipulations (Kirschen et al., 2020). Nevertheless, collegiate athletes have been reporting experiencing poor and insufficient sleep in reality (Mah et al., 2018). ...
... Despite this, we did not impose any restrictions on sleep duration, and no participants were extreme morning or evening chronotypes as in a previous study . Kirschen et al. (2020) conducted a systematic review on the relationship between sleep duration, sleep quality, and objective athletic performance among competitive athletes across 19 studies, representing 12 sports. They determined that the sports requiring speed, tactical strategy, and technical skill were the most sensitive to sleep duration manipulations. ...
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We evaluated the relationships of daily sleep duration and inconsistency with soft tennis competitive performance among 15 healthy collegiate soft tennis players (13 male, 2 female, mean age = 19.7 ± 0.8 years, height = 170.8 ± 7.3 cm, weight = 60.3 ± 5.6 kg, soft tennis experience = 8.7 ± 2.0 years). Sleep duration and inconsistency were determined by a 50-day sleep diary, which recorded sleep and wake times of sleep. Soft tennis athletic performance was evaluated by a service and baseline stroke accuracy test and the spider run test. Mean sleep duration was 7.4 ± 1.7 h. No correlation was found between long-term mean sleep duration and athletic performance. But inconsistency in sleep duration (SD of sleep duration) was inversely correlated with service score after controlling for soft tennis experience and sex ( r = −0.56, p = 0.046). There was no significant relationship between sleep inconsistency and other athletic performance. This result indicates that reducing the instability of sleep duration (i.e., sleep regular hours) in the long-term may have a positive effect on soft tennis players’ service performance. Although participants’ current mean sleep duration (7.4 h) was not as sufficient as the recommendation in sleep extension experiments (9–10 h), it revealed the importance for athletes to maintain regular sleep in daily life.
... Clearly, laboratory studies have been demonstrating that sleep extension and restriction affects athletic performance among collegiate players. And systematic review also had determined that the sports requiring speed, tactical strategy, and technical skill were the most sensitive to sleep duration manipulations (Kirschen et al., 2020). Nevertheless, collegiate athletes have been reporting experiencing poor and insufficient sleep in reality (Mah et al., 2018). ...
... Despite this, we did not impose any restrictions on sleep duration, and no participants were extreme morning or evening chronotypes as in a previous study . Kirschen et al. (2020) conducted a systematic review on the relationship between sleep duration, sleep quality, and objective athletic performance among competitive athletes across 19 studies, representing 12 sports. They determined that the sports requiring speed, tactical strategy, and technical skill were the most sensitive to sleep duration manipulations. ...
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... In contrast, sleep deprivation causes a reduced motor learning ability and an increased injury proneness, which in turn might explain the found differences between good and poor sleeping CFA [7]. Hence, in line with the assumptions from Kirschen and colleagues [22] and Watson [41], high sleep quality means an advantage of nightly processing of what has already been learned as well as an improved starting position to learn new movements and technical components efficiently and without injury. ...
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Thesis
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Athletic performance is mutually dependent upon individual constraints and practical interventions. Regarding the former, it is recognised that brain activity and sleep indices can modulate movement planning and execution. Concerning the strategies used in practice, contemporary short-term prescriptions have been adopted by conditioning professionals and physiotherapists with the primary intention to acutely enhance musculoskeletal power output or accelerate post-exercise recovery processes. These includes postactivation performance enhancement (PAPE)-based plyometric warm-up and induced cooling (COOL) through ice packs, respectively. However, it remain unknown whether measures of brain dynamics and natural sleep patterns influence skill-related performance in soccer. To date, the literature does not show a consensus for PAPE effectiveness in young populations. Generally, COOL also negatively affects subsequent lower limb movements requiring high force-velocity levels. Based on these assumptions, the general aim of the current thesis was to investigate the influence of internal individual constraints (EEG and sleep-derived indices) and effects of short-term practical interventions (PAPE and COOL) on the movement kinematics and performance aspects of soccer kicking in youth academy players. A series of six studies is presented. These include a literature review, one technical note and four original experimental research articles (two observational and two interventions) in an attempt to answer the questions defined in the research programme. From the data gathered here, it was possible to provide evidence that a) kick testing in studies systematically lacked resemblance to competition environments; b) occipital brain waves during the preparatory phase determines ball placement while late frontal signalling control both ankle joint in impact phase and post-impact ball velocity; c) poor sleep quality and late chronotype preference are linked to subsequent impaired targeting ability; d) acute enhancements achieved via PAPE/plyometric conditioning are purely neuromuscular, being slightly converted into kicking mechanics or performance improvements; e) in a hot environment, repeated high-intensity running efforts impair both ball placement and velocity whilst a local 5-minutes COOL application assists recovery of overall kick parameters and f) a markerless deep learning-based kinematic system appear as reliable alternative in capturing on-field kicking motion patterns. To conclude, both internal individual constraints (EEG and sleep quality) and a short-term practical intervention (cooling quadriceps/hamstrings with ice packs) have an acute impact in kicking performance in youth soccer context. A model integrating evidence from all papers is presented alongside limitations and recommendations for future studies in this field. Keywords: Technical skill; 3-dimensional kinematics; Accuracy; EEG; Human movement; Motor Control; Biomechanics.
... Silva et al. have shown that sleep efficiency could explain 44% of the total variance in the number of injuries, 24% of the total variance in absence time after injury (days), and 47% of the total variance in injury severity 29 . Furthermore, data indicate that sports requiring a high level of speed and technical skills, such as football, are more sensitive to sleep manipulation 30 . In our study, sleep duration ranged between 7-8 h, and there were no statistically significant differences between training camps and days leading up to a game. ...
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... Sleep is an important process that can both impair and improve the health of humans and animals 1,2 . Sleep plays a vital role in sensorimotor and athletic performance, providing physical, coordinative, and cognitive recovery 3,4 . ...
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Athletes and coaches believe that adequate sleep is essential for peak performance. There is ample scientific evidence which support the conclusion that sleep loss seems to stress many physiological functions in humans. The aim of this study was to determine the effect of one night’s sleep deprivation on intermittent exercise performance in the evening of the following day. Ten male Taekwondo players performed the Yo-Yo intermittent recovery test (YYIRT) in three sleep conditions (reference sleep night [RN], partial sleep deprivation at the beginning of night [PSDBN], partial sleep deprivation at the end of night [PSDEN]) in a counterbalanced order, allowing a recovery period ≥36 hr in between them. Heart rate peak (HRpeak), plasma lactate concentrations (Lac) and rating of perceived exertion (RPE) were measured during the test. A significant effect of sleep restriction was observed on the total distance covered in YYIRT (P<0.0005) and Lac (P<0.01) in comparison with the RN. In addition, performance more decreased after PSDEN (P<0.0005) than PSDBN (P<0.05). Also, Lac decreased significantly only after PS-DEN (P<0.05) compared with RN. However, there were no significant changes in HRpeak and RPE after the two types of partial sleep deprivation compared to RN. The present study indicates that short-term sleep restriction affect the intermittent performance, as well as the Lac levels of the Taekwondo players in the evening of the following day, without alteration of HRpeak and RPE.
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ABSTRACT: Sleep is essential for optimal health. The American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) developed a consensus recommendation for the amount of sleep needed to promote optimal health in adults, using a modified RAND Appropriateness Method process. The recommendation is summarized here. A manuscript detailing the conference proceedings and evidence supporting the final recommendation statement will be published in SLEEP and the Journal of Clinical Sleep Medicine.
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This study examined the associations between pre-game wellness and changes in match running performance normalised to either (i) playing time, (ii) post-match RPE or (iii) both playing time and post-match RPE, over the course of a field hockey tournament. Twelve male hockey players were equipped with global positioning system (GPS) units while competing in an international tournament (six matches over 9 days). The following GPS-derived variables, total distance (TD), low-intensity activity (LIA; <15 km/h), high-intensity running (HIR; >15 km/h), high-intensity accelerations (HIACC; >2 m/s²) and decelerations (HIDEC; >−2 m/s²) were acquired and normalised to either (i) playing time, (ii) post-match RPE or (iii) both playing time and post-match RPE. Each morning, players completed ratings on a 0–10 scale for four variables: fatigue, muscle soreness, mood state and sleep quality, with cumulative scores determined as wellness. Associations between match performances and wellness were analysed using Pearson’s correlation coefficient. Combined time and RPE normalisation demonstrated the largest associations with Δwellness compared with time or RPE alone for most variables; TD (r = −0.95; −1.00 to −0.82, p = .004), HIR (r = −0.95; −1.00 to −0.83, p = .003), LIA (r = −0.94; −1.00 to −0.81, p = .026), HIACC (r = −0.87; −1.00 to −0.66, p = .004) and HIDEC (r = −0.90; −0.99 to −0.74, p = .008). These findings support the use of wellness measures as a pre-match tool to assist with managing internal load over the course of a field hockey tournament. Highlights • Fixtures during international field hockey tournaments are typically congested and impose high physiological demands on an athlete. To minimise decrements in running performance over the course of a tournament, measures to identify players who have sustained high internal loads are logically warranted. • The present study examined the association between changes in simple customised psychometric wellness measures, on changes in match running performance normalised to (i) playing time, (ii) post-match RPE and (iii) playing time and post-match RPE, over the course of a field hockey tournament. • Changes in match running performance were better associated to changes in wellness (r = −0.87 to −0.95), when running performances were normalised to both time and RPE compared with time or RPE alone. • The present findings support the use of wellness measures as a pre-match tool to assist with managing internal load over the course of a field hockey tournament. Improved associations between wellness scores and match running performances were evident, when running variables were normalised to both playing time and post-match RPE.
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BACKGROUND: Most of the available literature related to aspects of sleep-deprivation is primarily focused on memory and learning and studies regarding its effects on selective-attention and/or physical performance especially the isometric-force are scarce. Moreover, the available literature included general population or some team sports (eg; volleyball). However, only few studies were done on athletes involved in combat sports (eg; Karate). The aim of the present study was to determine the effects of a total one-night-sleep-deprivation (NSD) on activator- and inhibitor-processes of selective-attention and on maximal-isometric-force in Karate athletes. METHODS: Twelve Karate boys (age mean±SD: 16.9±0.8 Yrs) were included. The protocol consists of two successive sessions: a normal-night-sleep (NNS) and a total one-NSD. After each night, athletes performed selective-attention and muscle-strength-tests during the same following three periods (P) of the day: P1NNS or P1NSD: 8-9 am; P2NNS or P2NSD: 12 am-1 pm; P3NNS or P3NSD: 4-5 pm. The activator [simple- and choice-reaction-times (SRT, CRT, respectively)] and inhibitor (negative-priming) processes were evaluated “Superlab4.5 software, Cedrus, San Pedro, USA”. Maximal-force and maximal-force-time (MFT) of brachial biceps isometric-contraction were evaluated (dynamometer Globus ergo system®; Italy). Data were expressed as mean±SD. A non-parametric test was used to evaluate the sessions (NNS vs. SND for the same period) and time (P1NNS vs. NSD periods’) effects. RESULTS: All athletes completed tests realized after NNS. 12, 11 and 4th athletes finished, respectively, P1NSD, P2NSD and P3NSD. Sessions effects: no statistical significant difference was found. Time effects: i) Significant increase of SRT at P2NSD vs. P1NNS (respectively, 345±47 vs. 317±33 ms); ii) Significant increase of MFT at P2NSD vs. P1NNS (respectively, 2172±260 vs.1885±292 ms) and iii) No significant changes of CRT; negative-priming reaction-time or MFT data. CONCLUSION: Total one-NSD affects both activator-processes of selective-attention and maximal-isometric-strength, two qualities often used in Karate sports.
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This study aimed to evaluate body composition, sleep, precompetitive anxiety and dietary intake on the elite female gymnasts' performance prior to an international competition. Sixty-seven rhythmic gymnasts of high performance level were evaluated in relation to sport and training practice, body composition, sleep duration, daytime sleepiness by the Epworth Sleepiness Scale (ESS), sleep quality by the Pittsburgh Sleep Quality Index (PSQI), precompetitive anxiety by the Sport Competition Anxiety Test form A (SCAT-A) and detailed dietary intake just before an international competition. Most gymnasts (67.2%) suffered from mild daytime sleepiness, 77.6% presented poor sleep quality and 19.4% presented high levels of precompetitive anxiety. The majority of gymnasts reported low energy availability (EA) and low intakes of important vitamins including folate, vitamins D, E and K; and minerals, including calcium, iron, boron and magnesium (p < .05). Gymnasts' performance was positively correlated with age (p = .001), sport practice (p = .024), number of daily training hours (p = .000), number of hours of training/week (p = .000), waist circumference (WC) (p = .008) and sleep duration (p = .005). However, it was negatively correlated with WC/hip circumference (p = .000), ESS (p = .000), PSQI (p = .042), SCAT-A (p = .002), protein g/kg (p = .028), EA (p = .002) and exercise energy expenditure (p = .000). High performance gymnasts presented poor sleep habits with consequences upon daytime sleepiness, sleep quality and low energy availability.