International Journal of Sports Physiology and Performance, 2013, 8, 556-564
© 2013 Human Kinetics, Inc.
www.IJSPP-Journal.com
ORIGINAL INVESTIGATION
The Effect of Overnight Sleep Deprivation
After Competitive Rugby League Matches
on Postmatch Physiological and Perceptual Recovery
Melissa Skein, Rob Duffield, Geoffrey M. Minett, Alanna Snape, and Alistair Murphy
Purpose: This study examined the effects of overnight sleep deprivation on recovery after competitive rugby
league matches. Methods: Eleven male amateur rugby league players played 2 competitive matches, followed by either a normal night’s sleep (~8 h; CONT) or a sleep-deprived night (~0 h; SDEP) in a randomized
fashion. Testing was conducted the morning of the match, immediately postmatch, 2 h postmatch, and the
next morning (16 h postmatch). Measures included countermovement-jump (CMJ) distance, knee-extensor
maximal voluntary contraction (MVC) and voluntary activation (VA), venous-blood creatine kinase (CK) and
C-reactive protein (CRP), perceived muscle soreness, and a word–color recognition cognitive-function test.
Percent change between postmatch and 16-h postmatch was reported to determine the effect of the intervention
the next morning. Results: Large effects indicated a greater postmatch to 16-h-postmatch percentage decline
in CMJ distance after SDEP than in CONT (P = .10–.16, d = 0.95–1.05). Similarly, the percentage decline in
incongruent word–color reaction times was increased in SDEP trials (P = .007, d = 1.75). Measures of MVC
did not differ between conditions (P = .40–.75, d = 0.13–0.33), although trends for larger percentage decline
in VA were detected in SDEP (P = .19, d = 0.84). Furthermore, large effects indicated higher CK and CRP
responses 16 h postmatch in SDEP than in CONT (P = .11–.87, d = 0.80–0.88). Conclusions: Sleep deprivation
negatively affected recovery after a rugby league match, specifically impairing CMJ distance and cognitive
function. Practitioners should promote adequate postmatch sleep patterns or adjust training demands the next
day to accommodate the altered physical and cognitive state after sleep deprivation.
Keywords: sleep loss, intermittent-sprint exercise, muscle damage, team sports
Competitive rugby league matches result in high
neuromuscular, physiological, and perceptual strain
due to repeated high-intensity efforts and interplayer
collisions.1,2 Accordingly, postmatch recovery can be
prolonged, interrupting subsequent recovery or training
sessions.3 For instance, torque and twitch-contractile
properties of maximal voluntary contraction (MVC)
have been shown to be suppressed 2 hours postmatch.3
Furthermore, McLellan et al4 reported that countermovement-jump (CMJ) peak power is reduced up to 24 hours
postmatch, alongside elevated biochemical markers of
stress and muscle damage. Although there is evidence of
alterations in physiological states postmatch and during
recovery periods,3,4 limited research has examined the
influence of postmatch circumstances that potentially
impair recovery.
Skein, Snape, and Murphy are with the School of Human
Movement Studies, Charles Sturt University, Bathurst, NSW,
Australia. Duffield is with the Faculty of Health, University of
Technology, Sydney, Sydney, NSW Australia. Minett is with
the School of Exercise and Nutrition Sciences, Queensland
University of Technology, Brisbane, QLD, Australia.
556
Situations resulting in disruptions to postmatch
recovery that are commonly experienced by team-sport
athletes may include travel demands, unfamiliar sleeping arrangements, anxiety, or social commitments, all
of which are known to interrupt sleep patterns.5–8 Sleep
deprivation has been shown to negatively affect ensuing
exercise performance such as walking time to exhaustion,9 submaximal strength,10 peak power during a maximal cycling effort,11 and distance covered in self-paced
treadmill running.12 More pertinent to rugby league,
Skein et al13 reported a reduction in intermittent-sprint
performance, MVC, and muscle glycogen concentration
and an increase in perceptual stress after 30-hour sleep
deprivation. While these studies provide insight into the
effects of sleep deprivation on ensuing performance,
minimal research has examined the effects of sleep
deprivation on postexercise recovery, particularly from
real-world competitive team-sport matches.
The mechanisms that explain reduced performance
after sleep deprivation are unknown but are reported to
include increased cardiovascular and thermoregulatory
strain, alterations in hormone regulation, and increased
waking metabolic demands.14,15 It is also known that
sleep enhances anabolic processes, and, particularly
Recovery From Rugby After Sleep Deprivation 557
when tissue damage is present, the rate of healing
is greater during sleep.16 Furthermore, reductions in
exercise performance have been attributed to increased
perceptual stress, as observed from Profile of Mood
States questionnaires,17 or increased rating of perceived
exertion (RPE) for a given workload.18 The array of purported mechanisms may be due to the inability to blind
subjects to the sleep condition, resulting in a negative
placebo (nocebo) effect on exercise performance and
cognitive function.19 Nevertheless, it appears that exercise
performance and cognitive function are impaired after
acute sleep deprivation, although the contribution of the
proposed mechanisms are unclear, particularly on the
postexercise recovery process.6
Accordingly, the current understanding of sleep
deprivation and its ensuing effect on recovery after
exercise is lacking, particularly in a competitive teamsport scenario. The effects of increased physiological
and perceptual stress on performance outcomes are also
unclear. Therefore, this study aimed to examine the effect
of sleep deprivation on next-day recovery of neuromuscular, physiological, and cognitive function after rugby
league competition. We hypothesized that 1 night’s sleep
deprivation would negatively affect postmatch recovery
of neuromuscular and cognitive function and increase
perceptual stress the following morning.
Methods
Subjects
Eleven male amateur rugby league players volunteered to
participate in this study. The mean ± SD age, stature, and
body mass for all participants were 20.4 ± 2.5 years, 178.9
± 5.7 cm, and 83.0 ± 11.3 kg, respectively. Participants
competed at first- (n = 7) and second-grade (n = 4) level in
a university-grade rugby league competition and reported
completing 1 competitive match, 2 sport-specific skills
sessions, and 2 or 3 strength-training sessions per week.
Written informed consent was obtained after explanation
of all procedures and possible risks involved. All experimentation was approved by the university committee on
ethics in human research.
Design
In a randomized, crossover design, participants completed
2 trials (sleep deprivation [SDEP] vs control [CONT])
to examine the neuromuscular, cognitive, and perceptual recovery the morning after a rugby league match.
Participants reported for baseline measures at 8 AM (~7
h prematch), within 10 to 20 minutes immediately postmatch, 2 hours postmatch (at the start of the evening),
and the following morning at a standardized time (8 AM;
16 h postmatch). Accordingly, this study simulated an
ecologically valid sporting environment where players
may encounter sleep disruption after a match but are still
required to attend recovery sessions the following morning. Participants abstained from exercise and alcohol 24
hours before and all caffeine 3 hours before each match
and throughout the intervention period. After the match
subjects were provided with a standardized evening meal
consisting of 30.5 kJ/kg energy, 3.0 g/kg carbohydrate,
and 0.9 g/kg protein and did not consume additional food
until the following morning after 16-hour-postmatch
measures. Self-reported physical activity and dietary
records were completed for the 24 hours before exercise
for the initial trial and replicated thereafter.
Methodology
Rugby League Match. Participants completed an
80-minute rugby league match as part of their respective
first- and second-grade teams. Matches used throughout
the study were midseason home games against teams
of similar competition standing. During all matches,
distance and speed of movement were recorded by
1-Hz global-positioning-system (GPS; SPI elite,
GPSports Systems, Canberra, Australia) devices worn
in a customized harness on the cervical vertebrae.
Data for distance and mean speeds were reported in
the following categories: low-intensity activity (<14.4
km/h), high-intensity running (>14.5 km/h), and veryhigh-intensity running (>20 km/h).20 Mean speed (m/s)
was calculated based on distance covered divided by
time in play. Matches were filmed using a digital video
camcorder (Canon MV920, Canon Australia Pty Ltd,
Sydney, Australia) positioned at the halfway line of
the field. Postmatch notational analysis was performed
to quantify the number of tackles and hit-ups during
the match as defined by the observation of an impact
with the opposition players as part of carrying the ball
or tackling the ball carrier. In addition, an RPE (Borg
CR-10)21 was obtained 15 minutes after each match.
While competitive matches were not standardized
for work, measures of distance, mean speeds, and
interplayer contacts allowed comparison of external
load between matches.
Sleep Intervention. The 2 randomized interventions
included 1 night of normal sleep (~8 h; CONT) and 1
night of no sleep (~0 h; SDEP). After 2-hour-postmatch
measures, participants remained in the laboratory for
the ensuing night. A standardized meal was provided
at 8 PM, after which participants were provided with
leisure activities (movies, computers, reading material)
until 11 PM. In CONT, participants retired to selfprovided bedding in the darkened laboratory (0 ± 2 lux;
Lux light meter, Digitech, Rydalmere, Australia) by
11:30 PM, while SDEP participants remained awake
and sedentary until the next day in a lit part of the
laboratory (80 ± 5 lux). The laboratory was monitored
by the research team, and participants were observed
to ensure compliance with the respective intervention.
Heart-rate (HR) monitors (Polar Electro-Oy RS232,
Kempele, Finland) were worn by all participants
during the night to provide an indirect indication of
physical activity between conditions. Core temperature
(Tcore) was also recorded, via ingestion of a telemetric
558 Skein et al
capsule (VitalSense, Mini Mitter, Bend, OR, USA)
at approximately 10:30 AM to allow passage into the
digestive tract, with a telemetric receiver (VitalSense,
Mini Mitter, Bend, OR, USA). HR and Tcore measures
were recorded at 30-minute intervals throughout the night
from 10 PM until 8 AM the following morning without
waking participants.
and final 5 contractions were superimposed with an
electrical stimulus when peak torque was achieved, and
a potentiated twitch was delivered immediately postcontraction when the muscle was at complete rest. Peak MVC
was determined as the mean torque produced during the
MVC in the 50 milliseconds before the delivery of the
stimulus. VA was calculated using the twitch-interpolation technique.24
Measures
Physiological. Nude body mass was recorded pre­match,
Neuromuscular Performance. Participants completed
a repeated CMJ protocol prematch, postmatch, 2 hours
postmatch, and 16 hours postmatch as a measure of
lower-body power output. After a 5-minute warm-up on
a cycle ergometer (Ergomedic 828E Monark, Sweden)
at 80 rpm with 2 kp resistance (apart from postmatch),
participants completed 10 maximal CMJ repetitions. Peak
distance was measured using a linear position transducer
(G1706374B, Fitness Technology, Adelaide, Australia)
attached to a dowel rod positioned across the shoulders
and interfaced with specialized software (Ballistic
Measurement System Software, Fitness Technology,
Adelaide, Australia).The typical error of distance for
this measure has been previously reported as 0.023 m
for elite athletes,22 and the coefficient of variation for
subelite college athletes CMJ distance has been reported
as 2.8%.23
MVC and voluntary activation (VA) of the right
knee extensors were assessed using an isokinetic dynamometer (Kincom, Model 125, Chattanooga Group Inc,
Hixon, TN, USA). Subjects were seated and strapped to
the dynamometer across the chest and hips and near the
ankle (1.0 cm above the lateral malleolus) on the right
leg, with arms crossed to isolate movement of the right
knee extensors. Participants’ hip and knee position were
kept consistent between sessions. Muscle activation
was achieved using a double felt-tip electrode (Bipolar,
Cardinal Health, Madison, WI, USA) placed over the
femoral nerve on the anterior thigh 1.0 cm below the
inguinal fold. The electrical stimulus was delivered
via a stimulator (Digitimer Ltd, Welwyn Garden City,
Hertfordshire, England) linked to a BNC2100 terminal
block and connected to a signal-acquisition system
(PXI1024, National Instruments, Austin, TX, USA)
that sampled all data at 2000 z. Electrical stimulus was
delivered using a single square-wave pulse with a width
of 200 microseconds, which was driven using customized software (v8.0, LabView, National Instruments,
Austin, TX, USA).
Initially the current was applied in incremental steps
until a plateau occurred in peak twitch torque; it was
then increased by 10% to ensure supramaximal stimulation. Six resting evoked twitches were delivered to the
femoral nerve before participants completed isometric
contractions at 60%, 80%, and 100% of maximal effort.
The MVC protocol consisted of 15 × 3-second maximal
isometric contractions of the right knee extensors with
6-second recoveries between contractions.9 The initial
2 hours postmatch, and 16 hours postmatch on a set of
calibrated scales (BE-150K Scales, A&D, Thebarton,
Australia). Participants also provided a midstream urine
sample to measure urine specific gravity to indicate
hydration status (Refractometer 503, Nippon, Tokyo,
Japan). Urine output was also measured throughout the
intervention period via collection of urine output in a
jar that was weighed to determine total urine volume
(BE-150K Scales, A&D, Thebarton, Australia).
Venous blood was collected at each time point using
an evacuated venipuncture system and serum separator
tubes (BD Vacutainer, Sydney, Australia) and analyzed
for creatine kinase (CK) and C-reactive protein (CRP) as
markers of muscle damage and inflammation. Samples
were allowed to clot at room temperature before centrifugation (4000 rpm at 4°C for 10 min), with serum stored at
–20°C until analysis according to assay instructions (Siemens Healthcare Diagnostics Inc, Newark, DE, USA).
CK concentrations were determined using an enzymatic
method and bichromatic rate technique. CRP samples
were manually diluted according to manufacturer’s
instructions and analyzed with the particle-enhanced
turbidimetric immunoassay technique.
Perceptual and Cognitive Measures. Cognitive
function was measured at all time points using a modified
version of the Stroop color–word test.25 This computerbased test of cognitive function required subjects to react
to repeated color and word stimuli, analyzing response
time, accuracy, and total duration for congruent and
incongruent word–color stimuli responses. Questions
answered incorrectly were repeated during the test,
causing an increase in total test time. The acceptable
reliability of the modified Stroop test has been previously
reported with reliability coefficients of .71 to .79.26
Finally, perceptual muscle soreness (0 = normal to 10
= extremely sore) was assessed prematch, postmatch, 2
hours postmatch, and 16 hours postmatch.
Statistical Analysis
Data are reported as mean ± SD. A repeated-measures
2-way ANOVA (condition × time) was used to determine
significant differences for time and time by group, within
and between conditions, with significance at P < .05.
Effect sizes (Cohen d) were calculated to analyze the
magnitude of effect of the sleep intervention, with <.20
considered trivial, .20 to .39 small, .40 to .79 moderate,
and >.80 large. Given the inability to standardize the
Recovery From Rugby After Sleep Deprivation 559
work completed during the match, a paired t test was
also used to determine significant differences in the percentage change of measures from postmatch to 16 hours
postmatch, as this is the duration of time over which the
intervention was imposed. All analyses were conducted
using Statistical Package for Social Sciences (SPSS,
v17.0, Chicago, IL, USA).
Results
Match Loads and Neuromuscular
Performance
All GPS parameters, interplayer contacts, and RPE data
are presented in Table 1. There were no significant differences observed between conditions for any match-load
variables (P = .09–.74). However, moderate to large
effects demonstrated a higher mean speed (d = 0.87) and
peak speed (d = 0.48) during SDEP trials. This greater
match speed reflected a moderately higher RPE in the
SDEP condition (d = 0.52), with trivial to small effects
observed between conditions in all remaining match-load
variables (d = 0.11–0.24).
Changes in MVC did not significantly differ between
conditions, demonstrating trivial to small effects at
all time points (P = .40–.75, d = 0.13–0.33; Table 2).
Significant differences and moderate to large effects
indicated a reduced MVC in both conditions 2 hours
and 16 hours postmatch compared with prematch values
(P = .01–.02, d = 0.63–1.30). Furthermore, MVCs were
significantly lower than postmatch measures in SDEP
trials at the 2-hour and 16-hour time points (P = .02, d
= 0.67–0.76). There were no significant differences and
trivial to moderate effects in VA between (P = .25–.76,
d = 0.16–0.56; Table 2) and within conditions over time
(P = .12–.76, d = 0.14–0.66). Notably, large effects for
a reduced percentage change in postmatch to 16 hours
postmatch VA were evident in SDEP trials compared with
CONT (P = .19, d = 0.84).
While no significant differences and small effects
were apparent in mean and peak CMJ distances between
conditions prematch (P = .52–.63, d = 0.34–0.38), large
effects denoted higher mean and peak CMJ performance
in SDEP trials postmatch (d = 0.81–0.97) and 2 hours
postmatch (d = 0.96–1.18). In contrast, SDEP moderately
lowered peak CMJ distance compared with CONT 16
hours postmatch (d = 0.45) and similarly demonstrated
larger percentage declines in mean and peak CMJ performance from postmatch to 16 hours postmatch than in
CONT trials (P = .10–.16, d = 0.95–1.05).
Table 1 Match Loads During Competitive Rugby League Matches for Each Condition, Mean ± SD
Condition
Total distance
(m)
Mean speed
(m/min)
HIR (m)
VHIR (m)
Peak speed
(m/s)
Contacts (#)
RPE
6221 ± 701
6058 ± 1472
80.6 ± 9.7
71.6 ± 18.4a
796 ± 267
848 ± 334
217 ± 133
228 ± 147
27.7 ± 3.2
26.5 ± 3.9b
21.2 ± 8.1
22.3 ± 10.1
5.3 ± 1.4
4.7 ± 1.8b
Control
SDEP
Abbreviations: HIR, high-intensity running; VHIR, very-high-intensity running; RPE, rating of perceived exertion; SDEP, sleep deprivation. There
were no significant differences between conditions.
a
Large effect size between conditions (d > 0.80). b Moderate effect size between conditions (d = 0.40–0.79).
Table 2 Summary of Absolute Neuromuscular Performance for Each Condition, Mean ± SD
MVC (Nm)
VA (%)
Peak CMJ (m)
Mean CMJ (m)
Condition
Prematch
Postmatch
2 h postmatch
16 h postmatch
% change
control
SDEP
control
SDEP
control
SDEP
control
SDEP
210 ± 34
203 ± 32
89.3 ± 5.5
88.1 ± 7.1
0.36 ± 0.06
0.38 ± 0.02
0.32 ± 0.05
0.33 ± 0.02
193 ± 42
200 ± 38
91.1 ± 11.6
86.7 ± 10.2b
0.36 ± 0.06
0.39 ± 0.03a
0.31 ± 0.05
0.34 ± 0.03a
186 ± 35#
183 ± 34#^
86.9 ± 6.4
85.7 ± 11.2
0.36 ± 0.05
0.40 ± 0.04a
0.32 ± 0.04
0.35 ± 0.04a
176 ± 40#
181 ± 32#^
85.6 ± 11.9
84.4 ± 9.1
0.39 ± 0.06
0.37 ± 0.04b
0.34 ± 0.05
0.33 ± 0.03
–14.1 ± 17.2
–10.6 ± 11.3
–9.3 ± 13.1
–2.9 ± 7.7a
5.4 ± 19.0
–5.7 ± 8.3a
5.7 ± 20.5
–4.4 ± 6.5a
Abbreviations: MVC, maximal voluntary contraction; SDEP, sleep deprivation; VA, voluntary activation; CMJ, countermovement jump.
*Significantly different between conditions (P < .05). #Significantly different from prematch values (P < .05). ^Significantly different from postmatch values (P < .05).
a
Large effect size between conditions (d > 0.80). b Moderate effect size between conditions (d = 0.40–0.79).
560 Skein et al
Physiological
Significant differences and large effects were observed
for a higher Tcore between the hours of 2 and 4 AM during
SDEP compared with CONT (P = .004–.04, d = 0.83–3.38;
Figure 1). Similarly, there were significant differences and
large effects between conditions indicating an elevated
HR during the hours of 11:30 PM to 7 AM during SDEP
(P = .01–.04, d = 0.80–3.19; Figure 1). Both conditions
demonstrated significant change and large effects for HR
and Tcore over time (P = .001–.03, d = 1.52–5.62).
Measures of urine specific gravity demonstrated no
significant differences and small and moderate effects
between conditions prematch (CONT 1.022 ± 0.006
vs SDEP 1.022 ± 0.005, P = .62, d = 0.23) and 2 hours
postmatch (CONT 1.027 ± 0.007 vs SDEP 1.025 ± 0.009,
P = .07, d = 0.52). Large effects did indicate lower urine
specific gravity 16 hours postmatch in SDEP than in CONT
(CONT 1.022 ± 0.006 vs SDEP 1.019 ± 0.005, P = .11,
d = 0.86). The SDEP intervention elicited no significant
changes and trivial to small effects in total urine output
(CONT 1.16 ± 0.53 kg vs SDEP 1.05 ± 0.40 kg, P = .98,
d = 0.32) and nude mass recorded prematch (CONT 83.04
± 11.26 vs SDEP 83.84 ± 10.82 kg, P = .11, d = 0.10),
postmatch (CONT 82.52 ± 11.39 vs SDEP 83.71 ± 11.32
kg, P = .09, d = 0.15), 2 hours postmatch (CONT 82.95 ±
11.51 vs SDEP 83.71 ± 11.01 kg, P = .13, d = 0.10), and
16 hours postmatch (CONT 83.04 ± 11.59 vs SDEP 84.38
± 11.07 kg, P = .08, d = 0.17).
Biochemical
Neither CK nor CRP significantly differed between conditions at any time point (P = .11–.87; Figure 2). However,
moderate and large effects were apparent to demonstrate
elevated CK 2 hours postmatch (d = 0.65) and 16 hours
postmatch (d = 0.80) in the SDEP trial compared with
CONT. In addition, SDEP induced moderate and large
effects for higher CRP values than CONT postmatch
(d = 0.48) and 16 hours postmatch (d = 0.88). Competitive rugby league significantly increased CK at all time
points compared with prematch values (P = .001–.03,
d = 1.66–2.31), and although these findings were not
reflected in CRP (P = .20–.87), both conditions demonstrated higher values than at baseline 16 hours postmatch
(d = 0.81–1.69).
Figure 1 — (A) Core temperature and (B) heart rate over the intervention night for control and sleep-deprivation (DEP) conditions,
mean ± SD. *Significant difference between conditions (P < .05). a Large effect size between conditions (d > 0.80).
Recovery From Rugby After Sleep Deprivation 561
Figure 2 — (A) Creatine kinase (CK), (B) C-reactive protein (CRP), and (C) perceived muscle soreness for control (CONT) and
sleep-deprivation (SDEP) conditions, mean ± SD. *Significant difference between conditions (P < .05). a Large effect size between
conditions (d > 0.80). b Moderate effect size between conditions (d = 0.40–0.79).
Cognitive and Perceptual
Measures of cognitive recovery are presented in Table
3. Postmatch to 16-hour-postmatch percentage change
in the incongruent word–color stimuli responses was
significantly different between conditions (P = .007,
d = 1.75), and large effects demonstrate a lower decline
in total time in SDEP than in CONT (P = .05, d = 1.31).
There were no significant differences and only small to
moderate effects between conditions in total test time (P =
.07–.47, d = 0.25–0.70) and congruent word–color stimuli
responses (P = .10–.70, d = 0.17–0.68). Finally, although
largely higher prematch muscle soreness was apparent
in CONT (P = .18, d = 0.93; Figure 2), no significant
differences and trivial to moderate effects were detected
between conditions at all other time points (P = .37–.59,
d = 0.16–0.50). Significant differences and large effects
within both conditions indicate increased muscle soreness
562 Skein et al
Table 3 Summary of Cognition Results for Each Condition During a Modified Stroop Test, Mean ± SD
Condition
Total test time (s)
CRT (ms)
IRT (ms)
control
SDEP
control
SDEP
control
SDEP
Prematch
Postmatch
2 h postmatch
16 h postmatch
% change
86.3 ± 12.3
82.1 ± 12.6b
623.2 ± 117.3
575.1 ± 80.0b
690.4 ± 140.6
661.3 ± 145.9
84.3 ± 13.1
78.1 ± 7.5a
593.2 ± 94.0
579.8 ± 86.4
674.7 ± 124.2
594.0 ± 91.8*a
83.3 ± 8.8
79.1 ± 10.0b
635.0 ± 95.0
590.9 ± 109.5b
675.7 ± 118.1
632.8 ± 92.4*b
77.5 ± 9.3
79.2 ± 9.9
597.2 ± 91.2
608.8 ± 104.6
624.7 ± 89.6
667.8 ± 127.1b
–8.8 ± 10.0
0.8 ± 6.3*a
–0.4 ± 15.8
3.2 ± 11.2b
–7.5 ± 11.2
5.5 ± 13.7*a
Abbreviations: SDEP, sleep deprivation; CRT, congruent word-color reaction time; IRT, incongruent word-color reaction time.
*Significantly different between conditions (P < .05).
a
Large effect size between conditions (d > 0.80). b Moderate effect size between conditions (d = 0.40–0.79).
at all time points compared with prematch ratings (P =
.001–.02, d = 1.31–4.23).
Discussion
This study examined the effect of overnight sleep deprivation on the recovery of neuromuscular, physiological,
and cognitive function the morning after a rugby league
match. These data show that 1 night’s sleep deprivation
after a competitive rugby league match delays the recovery of lower-body power (mean and peak CMJ distance)
up to 16 hours postmatch, despite similar declines in
isolated MVC between conditions. Furthermore, sleep
deprivation slowed recovery of reaction-time responses
for color–word cognitive tasks. The mechanisms responsible for slowed CMJ and cognitive recovery may be associated with the trends of reduced VA and increased CK
and CRP release after sleep deprivation. Furthermore, as
previously suggested,12,13,19 the inability to blind subjects
to the conditions (CONT vs SDEP) may have influenced
recovery, creating a negative placebo effect. Regardless,
sleep deprivation after competitive rugby league matches
can negatively affect postmatch recovery of CMJ distance
and cognitive function.
The context of this study reflects a common issue
for team sports, whereby postmatch demands reduce
sleep before ensuing morning sessions. The current study
used a competitive real-world environment to determine
the effects of sleep deprivation on recovery; however,
such an environment also presents a limitation in that a
nonstandardized bout of exercise was performed. However, GPS data demonstrate similar external match loads
between conditions, with no differences in distances
covered, mean speeds, or high-intensity running. A
further limitation of the current study was the absence
of ActiGraphy measures to objectively record sleep
quantity, but measurements of HR and Tcore were used
as an alternative indication of activity. While acknowledged as only surrogate measures, elevated HR and Tcore
responses throughout the evening of the SDEP condition
highlight the absence of sleep and a disruption to the
sleep–wake cycle.27
The reduced percentage change in CMJ from postmatch to 16 hours postmatch (the duration of the sleep
intervention) suggests a blunted recovery of lower-body
power after SDEP compared with CONT. Such delayed
recovery in peak power is consistent with Takeuchi et al,28
who also reported slower 40-m-sprint times and reductions
in vertical-jump distance and isokinetic leg-extension
force (60° and 180°/s) after 64-hour sleep deprivation.
Similarly, Souissi et al11 examined lower-body power
using the 30-second Wingate test and reported a reduction
in peak and mean power output during the subsequent
afternoon (36-h sleep deprivation) but no effect during
morning testing (24-h sleep deprivation). The mechanisms
responsible for the differences in percentage change in
the current study may be associated with the trend for
reduced neural drive (VA) to the active musculature and
the increased skeletal-muscle damage (CK and CRP)
resulting in suppressed recovery of lower-body power.
However, the lack of significant between-conditions differences of the aforementioned variables may be due to
shorter duration of sleep deprivation, as previous studies
have reported extended sleep-deprivation protocols greater
than 30 hours.11–27 Furthermore, suppression of recovery
after SDEP may be due to the inability to blind subjects
to the conditions (SDEP vs CONT), and the knowledge
of being sleep deprived may have had a placebo effect
on lower-body power.13 Regardless, the current study
suggests that the recovery of lower-body power may be
suppressed by sleep loss after rugby matches.
Peak MVC was reduced in both conditions after the
rugby league match, further highlighting the effect of
match demands on skeletal-muscle force production.3,4
While rugby league matches reduced MVC postmatch,
a lack of difference between conditions in postmatch
to 16-hour-postmatch percentage change indicates that
recovery of isolated-joint MVC torque was minimally
affected by sleep deprivation, per se. These findings are
contrary to those of Skein et al,13 who reported reductions
in MVC and VA after 30-hour sleep deprivation, with
Recovery From Rugby After Sleep Deprivation 563
neuromuscular function measured in the afternoon after
the intervention. As mentioned previously, the shorter
sleep deprivation in the current study may explain the
lack of difference in MVC torque between conditions.
Furthermore, the trends for a greater reduction in VA
after sleep loss despite minimal effects on MVC suggest
that other factors associated with sleep deprivation—the
knowledge of being in a sleep-deprived state, increased
perceptual stress, increased metabolic activity, and
cognitive impairment—may have influenced recovery
of dynamic lower-body power, with limited effect on
isolated muscle contractile force.
Competitive rugby league can invoke substantial
structural damage to muscle tissue.29 The progressive
increase in CK after the match is an indirect indication of
muscle damage.29–31 Although not significantly different
between conditions, large effect sizes suggest a greater rise
in CK after sleep deprivation. However, the variation in
CK between players and in the match results in high variability,29–31 potentially affecting the lack of significance.
Similar to CK, moderate to large effect sizes suggest trends
for increased CRP after sleep loss, further indicating that
sleep loss may have a negative effect on the recovery of
muscle-damage markers after competitive matches. Sleep
is known to enhance anabolic processes, particularly in the
presence of tissue damage,16 which may account for the
observed trends in lowered CK and CRP responses after
a night’s sleep. However, a lack of statistical significance
may also be due to postmatch CK requiring ~72 hours
to return to baseline,28,30,31 and therefore an insufficient
duration to monitor postmatch responses was available
in the current study. Accordingly, while these findings
indicate the presence of muscle damage after the rugby
league match, trends indicate that 24-hour sleep deprivation can delay the recovery of postmatch skeletal-muscle
damage markers, although longer sleep deprivation may
be required to observe statistical significance.11–13
Finally, cognitive function is an important factor
during training and competition football and was assessed
in the current study via a modified Stroop test.25 Results
suggest that the cognitive response time to word–color
stimuli was negatively affected the morning after sleep
deprivation. Furthermore, large effect sizes suggest that
total reaction time and congruent reaction time were also
slowed by 24-hour sleep deprivation. Such findings corroborate previous studies reporting reaction time to be
significantly slower after sleep deprivation32 and suggest
that sleep deprivation can reduce alertness and attention,
ultimately causing an increase in reaction time to simple
and choice cognitive tasks.32 These slowed cognitive
responses after sleep deprivation have been suggested to
be more apparent in simple tasks that involve minimal
environmental stimulation.33 While it is not suggested
such simple word–color tasks represent the cognitive
demands of training or competitive football, the controlled context of the laboratory allows some suggestion
that response times to visual stimuli may be affected by
sleep loss.32 Accordingly, postmatch sleep deprivation
may result in altered cognitive functioning the following
morning, which may affect attention and decision-making
skills during ensuing training sessions.
In summary, the current data highlight the detrimental
effects of sleep deprivation on next-day recovery after a
competitive rugby league match. Sleep loss increased
cardiovascular and thermal loads during the night and
slowed cognitive responses the next morning, highlighting
the altered physiological load of wakefulness. Whether
these exacerbated physiological and cognitive loads
resulted in the blunted recovery of lower-body power
(CMJ distance) observed the following morning remains
unknown. While differences in CMJ percentage change
were evident between conditions, the lack of difference
in absolute values and the minimal effect on MVC may
be a time-of-day effect, in that sleep deprivation induces
greater decrements later in the day with a longer duration
of wakefulness. Regardless, practitioners should note that
the loss of sleep during the night after competitive matches
may result in players presenting for next-day sessions with
augmented physical fatigue, slower cognitive function,
and some suppression of lower-body power.
Practical Applications
Despite the extreme nature of sleep deprivation used here,
postmatch sleep loss after competitive matches results in
augmented physical fatigue, slower cognitive function,
and lower-body power suppression. As such, players may
present for training sessions the following morning in a
suboptimal state of preparedness for training. Accordingly, while obvious, avoidance of sleep deprivation
is recommended for rugby league players, along with
tailoring training sessions to suit the state of the players
based on the specificity of the circumstances.
References
1. Gabbett TJ. Influence of physiological characteristics on
selection in a semi-professional first grade rugby league
team: a case study. J Sports Sci. 2002;20:399–405.
PubMed doi:10.1080/026404102317366654
2.Gabbett TJ. Science of rugby league football: a
review. J Sports Sci. 2005;23(9):961–976. PubMed
doi:10.1080/02640410400023381
3. Duffield R, Murphy A, Snape A, Minett GM, Skein M.
Post-match changes in neuromuscular function and the
relationship to match demands in amateur rugby league
matches. J Sci Med Sport. 2012;15(3):238–243. PubMed
doi:10.1016/j.jsams.2011.10.003
4. McLellan CP, Lovell DI, Gass GC. Markers of postmatch
fatigue in professional Rugby League players. J Strength
Cond Res. 2011;25(4):1030–1039. PubMed
5. Bishop D. The effects of travel on team performance in
the Australian national netball competition. J Sci Med
Sport. 2004;7(1):118–122. PubMed doi:10.1016/S14402440(04)80050-1
564 Skein et al
6. Halson SL. Nutrition, sleep and recovery. Eur J Sport Sci.
2008;8(2):119–126. doi:10.1080/17461390801954794
7. Richmond L, Dawson B, Hillman DR, Eastwood P. The
effect of interstate travel on sleep patterns of elite Australian Rules footballers. J Sci Med Sport. 2004;7(2):186–
196. PubMed doi:10.1016/S1440-2440(04)80008-2
8. Sargent C, Halson S, Roach GD. Sleep or swim?: earlymorning training severely restricts the amount of sleep
obtained by elite swimmers. Eur J Sport Sci. 2012;1(6):
doi:10.1080/17461391.2012.696711.
9. Martin BJ, Chen H. Sleep loss and the sympathoadrenal
response to exercise. Med Sci Sports Exerc. 1984;16(1):56.
PubMed
10. Reilly T, Piercy M. The effect of partial sleep deprivation on
weight-lifting performance. Ergonomics. 1994;37(1):107–
115. PubMed doi:10.1080/00140139408963628
11.Souissi N, Sesboüé B, Gauthier A, Larue J, Davenne
D. Effects of one night’s sleep deprivation on anaerobic
performance the following day. Eur J Appl Physiol.
2003;89(3–4):359–366. PubMed doi:10.1007/s00421003-0793-7
12. Oliver SJ, Costa RJS, Laing SJ, Bilzon JLJ, Walsh NP. One
night of sleep deprivation decreases treadmill endurance
performance. Eur J Appl Physiol. 2009;107:155–161.
PubMed doi:10.1007/s00421-009-1103-9
13.Skein M, Duffield R, Edge J, Short M, Mündel T.
Intermittent-sprint performance and muscle glycogen following 30 h sleep deprivation. Med Sci Sports
Exerc. 2011;43(7):1301–1311. PubMed doi:10.1249/
MSS.0b013e31820abc5a
14. Chen HI. Effects of 30-h sleep loss on cardiorespiratory
functions at rest and in exercise. Med Sci Sports Exerc.
1991;23(2):R193. PubMed
15. Sawka MN, Gonzalez RR, Pandolf KB. Effects of sleep
deprivation on thermoregulation during exercise. Am J
Physiol. 1984;246(1 Pt 2):R72–R77. PubMed
16. Adam K, Oswald I. Sleep helps healing. Br Med J (Clin
Res Ed). 1984;289:1400–1401. PubMed doi:10.1136/
bmj.289.6456.1400
17.Meney I, Waterhouse J, Atkinson G, Reilly T, Davenne D. The effect of one night’s sleep deprivation
on temperature, mood, and physical performance in
subjects with different amounts of habitual physical
activity. Chronobiol Int. 1998;15(4):349–363. PubMed
doi:10.3109/07420529808998695
18.Myles WS. Sleep deprivation, physical fatigue, and the
perception of exercise intensity. Med Sci Sports Exerc.
1985;17(5):580. PubMed
19.Martin BJ. Effect of sleep deprivation on tolerance
of prolonged exercise. Eur J Appl Physiol Occup
Physiol. 1981;47(4):345–354. PubMed doi:10.1007/
BF02332962
20. Coutts AJ, Duffield R. Validity and reliability of GPS units
for measuring movement demands of team sports. J Sci
Med Sport. 2010;13(1):133–135. PubMed doi:10.1016/j.
jsams.2008.09.015
21. Borg G, Ljunggren G, Ceci R. The increase of perceived
exertion, aches and pain in the legs, heart rate and blood
lactate during exercise on a bicycle ergometer. Eur J Appl
Physiol Occup Physiol. 1985;54(4):343–349. PubMed
doi:10.1007/BF02337176
22. Cormack SJ, Newton RU, McGuigan MR, Doyle TLA.
Reliability of measures obtained during single and repeated
countermovement jumps. Int J Sports Physiol Perform.
2008;3:131–144. PubMed
23. Markovic G, Dizdar D, Jukic I, Cardinale M. Reliability
and factorial validity of squat and countermovement jump
tests. J Strength Cond Res. 2004;18(3):551–555. PubMed
24.Merton PA. Voluntary strength and fatigue. J Physiol.
1954;123:553–564. PubMed
25. Stroop JR. Studies of interference in serial verbal reactions. J Exp Psychol. 1935;18(6):643–662. doi:10.1037/
h0054651
26.Strauss GP, Allen DN, Jorgensen ML, Cramer SL.
Test-retest reliability of standard and emotional Stroop
tasks: an investigation of color–word and picture–word
versions. Assessment. 2005;12(3):330–337. PubMed
doi:10.1177/1073191105276375
27.Waterhouse J, Drust B, Weinert D, et al. The circadian
rhythm of core temperature: origin and some implications for exercise. Chronobiol Int. 2005;22(2):207–225.
PubMed doi:10.1081/CBI-200053477
28.Takeuchi L, Davis GM, Plyley M, Goode R, Shephard
RJ. Sleep deprivation, chronic exercise and muscular
performance. Ergonomics. 1985;28(3):591–601. PubMed
doi:10.1080/00140138508963173
29.McLellan CP, Lovell DI, Gass GC. Creatine kinase
and endocrine responses of elite players pre, during
and post rugby league match play. J Strength Cond
Res. 2010;24(11):2908–2919. PubMed doi:10.1519/
JSC.0b013e3181c1fcb1
30. Minett G, Duffield R, Bird SP. Effects of acute multinutrient supplementation on rugby union game performance
and recovery. Int J Sports Physiol Perform. 2010;5:27–41.
PubMed
31. Takarada Y. Evaluation of muscle damage after a rugby
match with special reference to tackle plays. Br J Sports
Med. 2003;37(5):416–419. PubMed doi:10.1136/
bjsm.37.5.416
32. Sagaspe P, Sanchez-Ortuno M, Charles A, et al. Effects
of sleep deprivation on color–word, emotional, and specific Stroop interference and on self-reported anxiety.
Brain Cogn. 2006;60(1):76–87. PubMed doi:10.1016/j.
bandc.2005.10.001
33. Van Dongen HP, Dinges DF. Sleep, circadian rhythms, and
psychomotor vigilance. Clin Sports Med. 2005;24(2):237–
249. PubMed doi:10.1016/j.csm.2004.12.007