Demandas físicas de jugadores de rugby league

1. Available online at www.sciencedirect.com
Journal of Science and Medicine in Sport 15 (2012) 80–86
Original research
Physical demands of professional rugby league training and competition
using microtechnology
Tim J. Gabbetta,b,∗, David G. Jenkinsb, Bruce Abernethyb,c
a School of Exercise Science, Australian Catholic University, Queensland, Australia
b School of Human Movement Studies, The University of Queensland, Queensland, Australia
c Institute of Human Performance, The University of Hong Kong, Hong Kong, China
Received 3 December 2010; received in revised form 16 May 2011; accepted 5 July 2011
Abstract
Objectives: To investigate the physical demands of professional rugby league match-play using microtechnology, and to compare these
demands with typical training activities used to prepare players for competition. Design: Prospective cohort study. Methods: Thirty elite
rugby league players participated in this study. Seven hundred and eighty-six training data sets and 104 data sets from National Rugby
League matches were collected over one playing season. Movement was recorded using a commercially available microtechnology unit
(minimaxX, Catapult Innovations), which provided information on speeds, distances, accelerations, physical collisions and repeated high-
intensity efforts. Results: Mean distances covered during match-play by the hit-up forwards, wide-running forwards, adjustables, and outside
backs were 3569 m, 5561 m, 6411 m, and 6819 m, respectively. Hit-up forwards and wide-running forwards were engaged in a greater number
of moderate and heavy collisions than the adjustables and outside backs, and more repeated high-intensity effort bouts per minute of play (1
bout every 4.8–6.3 min). The physical demands of traditional conditioning, repeated high-intensity effort exercise, and skill training activities
were all lower than the physical demands of competition. Conclusions: These results demonstrate that absolute distances covered during
professional rugby league matches are greater for outside backs, while the collision and repeated high-intensity effort demands are higher
for hit-up forwards and wide-running forwards. The specific physical demands of competitive play, especially those demands associated with
collisions and repeated high-intensity efforts, were not well matched by those observed in traditional conditioning, repeated high-intensity
effort exercise, and skills training activities. Further research is required to investigate whether modifications need to be made to these training
activities to better prepare players for the demands of National Rugby League competition.
© 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Keywords: Contact; Conditioning; Physical demands; Team sport; Physical preparation; GPS
1. Introduction
Time-motion analysis is of importance to applied sport
scientists and strength and conditioning coaches in order to
assist in the development of game-specific conditioning pro-
grams. While time-motion analysis has been used extensively
in most team sports,1 research into the physical demands and
movementspatternsofrugbyleaguematch-playislimited.2–4
In a study in the early 1990s, Meir et al.4 investigated the
∗ Corresponding author.
E-mail address: tim gabbett@yahoo.com.au (T.J. Gabbett).
movement patterns of forwards and backs, by filming props,
hookers, halfbacks, and wingers during two professional
rugby league matches. The total distance covered by players
was recorded with mean total distance ranging from 6.5 km
(prop) to 7.9 km (halfback). In a subsequent study, Meir et al.5
reported a significant increase in the total distances covered
by forwards (9.9 km) and backs (8.5 km), suggesting that
professional rugby league places considerable demands on
the aerobic energy system. While the investigations of Meir
et al.4,5 provided an important starting point for the study of
thephysicaldemandsofrugbyleague,conditioningprograms
that are based on total distances covered and mean work to
1440-2440/$ – see front matter © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.jsams.2011.07.004

2. T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86 81
rest ratios alone will likely result in players being underpre-
pared for the most demanding passages of competition.2,6,7
More recently, studies have investigated the high-intensity
running,8 tackling,3 and repeated effort demands2 of profes-
sional rugby league match-play. Austin et al.2 filmed and
coded the repeated high-intensity effort demands of profes-
sional rugby league hit-up forwards, adjustables, and outside
backs during competitive match-play. Hit-up forwards were
involved in significantly more repeated high-intensity effort
bouts than players from other positions and had the short-
est average recovery between bouts. The authors concluded
that repeated high-intensity effort bouts occurred frequently
during professional rugby league match-play and at critical
times during the game.
Due to the labor-intensive nature of video-based time-
motion analysis, most,4,5 but not all7–9 studies have been
limited to small sample sizes. With the introduction of global
positioningsystem(GPS)technology,sportscientistsarenow
able to gain information on the distances covered in low and
high-intensity activities performed by athletes during train-
ing and competition,10 however, the reliability and validity
of individual sprint and change of direction speed activities
are relatively poor.11 Recent evidence has shown that the
tri-axial accelerometers and gyroscopes embedded in these
microtechnology units offer a valid12 and reliable13 means of
automatically detecting the collisions and tackles that occur
in rugby league. The capacity to monitor the contact load
of rugby league players demonstrates the practical utility of
these microtechnology units.
Rugby league players use a combination of traditional
conditioning (i.e., high-intensity running without the ball),
repeated high-intensity effort training, skills ‘drills’, and
game-based training to prepare for competition.14 The bene-
fits of each of these activities is unclear, with limited research
detailing whether game-specific conditioning is superior to
other methods of conditioning at improving actual match
performance.15–17 Of the available research, studies have
shown that game-based training results in similar (and in
some cases greater) heart rate responses and perceived exer-
tion than interval running without the ball.15–17 In addition,
in elite soccer players, game-based training has been shown
to generally replicate the physical demands of domestic,
national, and international competition.7 However, a closer
examination of the repeated-sprint demands showed that
players completed significantly fewer repeated-sprint bouts
when using a wide range of game-based training activities
than in international competition. These results, which have
been confirmed by others,10 suggest that game-based train-
ing may develop players for the overall demands of team
sport competition, but with inadequate game design may not
specifically prepare them for the high-intensity, repeated-
sprint demands of competition. Equally, it is unclear how well
traditional interval running replicates (or exceeds) the contact
and repeated high-intensity effort demands (i.e., sprinting and
tackling) of competition, or whether repeated high-intensity
effort training matches the high-intensity running demands of
Table 1
Training mode, number of players and number of global positioning system
(GPS) samples obtained in professional National Rugby League players.
Training/competition mode Number of
players
Number of
samples
National Rugby League matches 22 104
Traditional conditioning 19 42
Repeated high-intensity effort 22 44
Game-based training 24 77
Skills 26 623
match-play. While non-specific traditional interval running is
used by conditioning coaches to promote adaptations in aer-
obic power,18 game-specific training is also needed in order
to adequately prepare players for the contact and repeated
high-intensity effort demands of the game. Conditioning pro-
grams that neglect these contact and repeated high-intensity
effort demands may result in players being underprepared for
the most demanding passages of competition.2 With this in
mind, the purpose of this study was to investigate the physical
demands of professional rugby league match-play using GPS
and associated microtechnology (i.e., tri-axial accelerometer
and gyroscope), and to compare these demands with typi-
cal training activities (i.e., traditional conditioning, repeated
high-intensity effort training, skills ‘drills’, and game-based
training) used to prepare players for professional rugby
league competition.
2. Methods
Thirty-elite male rugby league players from a National
Rugby League (NRL) squad [mean age, 23.6 (95% confi-
dence intervals, 22.2–25.0) yr] participated in this study. All
participants received a clear explanation of the study, includ-
ing information on the risks and benefits, and written consent
was obtained. All experimental procedures were approved by
the Institutional Review Board for Human Investigation.
Global positioning system (GPS) analysis was completed
during 124 training sessions (N = 26 players, totaling 786
training appearances) and 16 matches (N = 21 players, total-
ing 104 NRL appearances) (Table 1). Players were selected
from one of four positional groups representing the hit-up
forwards (i.e., props), wide-running forwards (i.e., second
rowers and locks), adjustables (i.e., hookers, halfbacks, five-
eighths, and fullbacks), and outside backs (i.e., centres and
wingers). Up to 20 players wore a GPS unit during any given
training session. Training data included GPS files from hit-
up forwards (N = 212 files), wide-running forwards (N = 225
files), adjustables (N = 215 files), and outside backs (N = 134
files). Match data included GPS files from hit-up forwards
(N = 23 files), wide-running forwards (N = 23 files), adjusta-
bles (N = 29 files), and outside backs (N = 29 files). Players
wore the same microtechnology unit for each session, and all
sessions were completed during the one playing season.

3. 82 T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86
Training data were collected over a 10-month period
that included all pre-season and in-season skill, condition-
ing, repeated high-intensity effort exercise, and game-based
training sessions. The players engaged in traditional condi-
tioning activities such as maximal aerobic speed and interval
training without a ball. Repeated high-intensity effort activ-
ities that included repeated sprinting and tackling were also
includedinthetrainingprogram.Exercise-to-restratiosbased
on the most demanding passages of play expected during
competition were used for these drills.2 Game-based train-
ing/conditioning activities (e.g., small-sided training games
played on a reduced-sized pitch) were used to improve phys-
ical qualities, technical skill, and decision-making. Games
were often played with reduced player numbers on a large
field, and were designed to achieve high running loads and a
high number of repeated high-intensity efforts. Skills activ-
ities were designed to develop passing and catching ability,
running lines, tackling technique, support play, defensive line
speed and shape, and ball control. Recovery skill sessions and
final team sessions before matches were excluded from the
analysis.
While there were some differences in the intensity of train-
ing activities performed throughout the season, the types
of activities in the pre-season training phase (e.g., basic
skills, light and full contact tackling drills and longer interval
running) were similar to the early competition and late-
competition training phases (e.g., light contact tackling drills,
advanced skills, and shorter repeated-sprint training).
Movement was recorded by a minimaxX GPS unit (Team
2.5, Catapult Innovations, Melbourne, Australia) sampling
at 5 Hz. The GPS signal provided information on speed,
distance, position, and acceleration. The GPS unit also
included tri-axial accelerometers and gyroscopes sampling
at 100 Hz, to provide greater accuracy on speed and accel-
eration, and information on physical collisions and repeated
high-intensity efforts. The unit was worn in a small vest, on
the upper back of the players.
Data were categorized into (i) movement speed bands, cor-
responding to low (0–5 m s−1) and high (>5 m s−1) speeds;19
(ii) recovery between efforts, corresponding to short (<30 s),
moderate (30 s to 2 min), and long (>2 min) recovery;
and (iii) repeated high-intensity effort bouts. A repeated
high-intensity effort bout was defined as 3 or more high accel-
eration (≥2.79 m s−2),20 high speed, or contact efforts with
less than 21 s recovery between efforts.2,6,7 The minimaxX
units have been shown to have acceptable validity and reli-
ability for estimating longer distances at walking through
to striding speeds,11,21 although large measurement errors
and poor validity have been reported for the measurement
of individual sprints, accelerations, and change of direction
efforts.11 The minimaxX units have been shown to offer a
valid measurement of tackles and repeated efforts commonly
observed in collision sports.12
Differencesamongpositionalgroupsandbetweentraining
and match-play were compared using statistical significance
testing and by using a practical approach based on the real-
world relevance of the results.22 Firstly, differences in the
physical demands (i.e., distance covered at low and high-
speeds, mild, moderate, and heavy collisions, and repeated
high-intensity effort activity) among playing positions were
compared using a one way analysis of variance. Compar-
isons between the overall match demands of all playing
positions and those recorded during traditional conditioning,
repeated high-intensity effort exercise, game-based train-
ing, and skill training activities were also compared using
a one way analysis of variance. The source(s) of any sig-
nificant differences involving multiple groups were followed
up using a Tukey honestly significant difference post hoc
test. The level of significance was set at p < 0.05 and all
data are reported as means and 95% confidence intervals
(CI). Secondly, given the practical nature of the study, dif-
ferences among playing positions, and match and training
demands were also analyzed using Cohen’s effect size (ES)
statistic.23 Effect sizes of <0.09, 0.10–0.49, 0.50–0.79, and
>0.80 were considered trivial, small, moderate, and large,
respectively.22
3. Results
The mean absolute distances covered during match-play
were higher for the outside backs than the hit-up forwards,
wide-running forwards, and adjustables, however no differ-
ences were observed among groups for the relative distances
covered per minute of match-play (Table 2). The single
greatest total distance covered by a hit-up forward, wide-
running forward, adjustable, and outside back was 6666 m
(110 m/min), 8165 m (142 m/min), 12692 m (165 m/min),
and 9561 m (124 m/min), respectively. The hit-up forwards
covered less distance at low movement speeds than the wide-
running forwards, adjustables, and outside backs, while the
outside backs covered greater distances at high movement
speeds than the other positional groups. The hit-up forwards
and wide-running forwards were involved in a greater number
of collisions (ES = 1.41–2.75; 0.63–2.00) and repeated high-
intensity effort bouts (ES = 0.57–0.98; 0.22–0.52) per minute
of match-play than the adjustables and outside backs. The sin-
gle greatest frequency of collisions per minute of match-play
for the hit-up forwards, wide-running forwards, adjustables,
and outside backs was 2.1, 1.2, 1.3, and 0.8, respectively.
Thesinglegreatestfrequencyofrepeatedhigh-intensityeffort
bouts per minute of match-play for the hit-up forwards, wide-
running forwards, adjustables, and outside backs was 0.5, 0.4,
0.7, and 0.3, respectively.
The relative distance covered in traditional condition-
ing exceeded the relative distance covered in match-play,
while repeated high-intensity effort exercise and skill activ-
ities were lower (Table 3). The collision and repeated
high-intensity effort demands of traditional conditioning
and skill training activities were both lower than that
of competition. Game-based training exceeded the run-

4. T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86 83
Table 2
Distance covered, repeated high-intensity effort, and collision demands of different positional groups during National Rugby League competition.
Hit-up forwards Wide-running forwards Adjustables Outside backs
Time (min) 38.0 (33.6–42.5) 58.5 (51.6–65.3)* 64.1 (55.7–72.4)* 73.5 (68.1–79.0)*,†
Low-speed distance (m) 3334 (2892–3776) 5143 (4541–5746)* 5974 (5138–6811)* 6235 (5753–6718)*
High-speed distance (m) 235 (185–285) 418 (355–481)* 436 (365–508)* 583 (532–633)*,†,‡
Total distance (m) 3569 (3088–4051) 5561 (4916–6207)* 6411 (5513–7310)* 6819 (6302–7336)*
Relative distance (m/min) 94 (89–98) 96 (91–101) 101 (94–108) 93 (89–98)
Collisions
Mild (no.) 4 (2–5) 4 (2–6) 4 (3–5) 2 (1–3)
Moderate (no.) 22 (18–27) 24 (20–28) 19 (15–23) 12 (10–14)*,†
Heavy (no.) 16 (14–18) 17 (15–20) 11 (9–14)*,† 14 (12–16)
Total (no.) 42 (35–48) 45 (38–52) 34 (28–40) 28 (23–32)*,†
Mild frequency (no/min) 0.09 (0.05–0.13) 0.07 (0.04–0.09) 0.07 (0.05–0.10) 0.03 (0.02–0.04)*,‡
Moderate frequency (no/min) 0.58 (0.49–0.66) 0.39 (0.33–0.45)* 0.33 (0.25–0.41)* 0.17 (0.14–0.20)*,†,‡
Heavy frequency (no/min) 0.43 (0.38–0.48) 0.29 (0.25–0.32)* 0.20 (0.16–0.23)*,† 0.20 (0.17–0.22)*,†
Total frequency (no/min) 1.09 (0.96–1.22) 0.76 (0.69–0.84)* 0.58 (0.45–0.71)*,† 0.38 (0.32–0.43)*,†,‡
Repeated high-intensity efforts
Bouts (no.) 8.0 (5.9–10.1) 9.9 (7.3–12.5) 8.6 (5.8–11.4) 8.5 (6.5–10.4)
Efforts per bout (no.) 6.2 (5.3–7.1) 5.5 (4.6–6.4) 5.5 (4.5–6.4) 5.3 (4.5–6.1)
Mean effort duration (s) 2.1 (1.9–2.3) 1.8 (1.6–2.0) 1.6 (1.4–1.7)* 1.5 (1.3–1.7)*
Maximum effort duration (s) 6.0 (4.9–7.2) 5.6 (4.9–6.2) 4.7 (4.1–5.4) 5.5 (4.7–6.4)
Effort recovery (s) 6.4 (5.7–7.1) 5.9 (5.1–6.8) 5.9 (4.9–7.0) 5.9 (5.1–6.6)
Bout frequency 1 every 4.8 min 1 every 6.3 min 1 every 7.7 min 1 every 9.1 min
Global positioning system (GPS) analysis was completed during 16 matches (N = 21 players, totaling 104 NRL appearances). Repeated high-intensity efforts:
3 or more maximal acceleration sprint efforts, very-high speed sprint efforts, and/or tackle efforts with less than 21 s between efforts. Data are means (and 95%
confidence intervals).
* Significantly different (p < 0.05) from hit-up forwards.
† Significantly different (p < 0.05) from wide-running forwards.
‡ Significantly different (p < 0.05) from adjustables.
ning demands of match-play. The repeated high-intensity
effort demands of game-based training were similar to
match-play. In addition, game-based training had simi-
lar mild, moderate, and overall collision frequency to
NRL competition, but lower heavy collision demands than
match-play.
4. Discussion
This study is the first to investigate the physical demands
of professional rugby league match-play and training
using commercially available microtechnology (i.e., GPS,
accelerometers, and gyroscopes) units. In addition, this is
the first study to verify whether current training practices
reflect the demands of NRL competition. Consistent with
some,3 but not all9 studies, the data show that absolute
distances covered are greater for the adjustables, outside
backs, and wide-running forwards than for the hit-up for-
wards. However, the relative distances covered (per minute
of match-play) are similar among positional groups. Fur-
thermore, and in agreement with others,2,3,24 the collision
and repeated-effort demands of match-play were higher for
the hit-up forwards and wide-running forwards than for the
adjustables and outside backs. Neither traditional condition-
ing, repeated high-intensity effort exercise, nor skill activities
replicated the physical demands of match-play. These data
may be used by conditioning coaches to develop game- and
position-specific training programs for professional rugby
league players.
The mean distances covered during match-play by the
hit-up forwards, wide-running forwards, adjustables, and
outside backs were 3569 m, 5561 m, 6411 m, and 6819 m,
respectively. Due to differences in playing time, the relative
distances covered were similar among the hit-up forwards
(94 m/min), wide-running forwards (96 m/min), adjustables
(101 m/min), and outside backs (93 m/min). These relative
distances are slightly lower than distances previously esti-
mated from video tracking (106 m/min) of professional rugby
league competition,8 and may reflect the combined error
associated with GPS and video-based tracking technologies,
differences in physical qualities or playing styles of the teams
analyzed, or rule changes, most notably the increase from
one to two referees since the previous study8 was published.
Outside backs covered greater distances at lower movement
speeds, and performed more high-speed running (8.0 m/min)
than the hit-up forwards (6.2 m/min), wide-running forwards
(7.2 m/min), and adjustables (6.9 m/min) positional groups.
While some of the differences in high-speed running may
be explained by the greater playing time in this positional
group, centres and wingers are often required to lead the
kick-chase (i.e., where attacking teams kick the ball into
the opposition team’s territory and then aim to restrict the
opposition team’s gains in field position) and along with
the fullback, are predominantly responsible for kick-returns.
The 2.5-fold greater absolute high-speed running distance

5. 84 T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86
Table 3
Distance covered, repeated high-intensity effort, and collision demands of National Rugby League matches, traditional conditioning activities, repeated
high-intensity effort activities, game-based training activities, and skill training activities.
NRL competition Traditional
conditioning
Repeated
high-intensity
effort
Game-based
training
Skills
Time (min) 59.7 (55.6–63.8) 12.8 (10.7–14.9)* 43.6 (36.8–50.5)*,† 12.6 (11.8–13.4)*,‡ 77.8 (76.6–78.9)*,†,‡,#
Low-speed distance (m) 5279 (4901–5658) 1011 (779–1243) 3295 (3022–3567) 1474 (1371–1577) 4203 (4138–4267)
High-speed distance (m) 429 (391–467) 1069 (932–1206) 405 (283–528) 261 (235–288) 214 (206–222)
Total distance (m) 5709 (5299–6118) 2080 (1775–2385)* 3700 (3344–4056)*,† 1708 (1601–1816)*,‡ 4423 (4357–4490)*,†,‡,#
Relative distance (m/min) 96 (93–99) 164 (160–169)* 91 (84–99)† 137 (133–141)*,†,‡ 58 (57–59)*,†,‡,#
Collisions
Mild (no.) 3 (2–4) – 5 (3–7) 4 (3–5) 8 (7–9)*,#
Moderate (no.) 19 (17–21) – 20 (16–24) 5 (4–6)*,‡ 15 (14–16)*,#
Heavy (no.) 15 (14–16) – 1 (0–1)* 2 (1–2)* 3 (2–3)*
Total (no.) 37 (34–39) – 26 (21–30)* 13 (11–15)*,‡ 26 (24–28)*,#
Mild frequency (no/min) 0.06 (0.05–0.07) – 0.13 (0.09–0.16) 0.31 (0.25–0.37)*,‡ 0.10 (0.09–0.11)*,#
Moderate frequency (no/min) 0.34 (0.29–0.38) – 0.54 (0.42–0.67) 0.38 (0.31–0.45)‡ 0.20 (0.19–0.21)*,‡,#
Heavy frequency (no/min) 0.26 (0.23–0.28) – 0.02 (0.00–0.03)* 0.12 (0.09–0.15)*,‡ 0.04 (0.03–0.04)*,#
Total frequency (no/min) 0.68 (0.60–0.75) – 0.69 (0.55–0.83) 0.81 (0.61–1.11)*,‡ 0.29 (0.28–0.30)*,‡,#
Repeated high–intensity efforts
Bouts (no.) 8.7 (7.5–9.9) 0.1 (0.0–0.2)* 3.6 (2.7–4.5)* 2.8 (2.3–3.4)* 5.2 (4.9–5.5)*,†,#
Efforts per bout (no.) 5.6 (5.2–6.1) 0.3 (0.0–0.8)* 5.9 (4.9–6.8)† 3.8 (3.1–4.4)*,† 5.7 (5.4–5.9)†,#
Mean effort duration (s) 1.7 (1.6–1.8) 0.1 (0.0–0.2)* 1.3 (1.1–1.5)*,† 0.9 (0.8–1.1)*,† 1.2 (1.1–1.3)*,†,#
Maximum effort duration (s) 5.5 (5.0–5.9) 0.1 (0.0–0.4)* 2.3 (1.9–2.7)* 2.6 (2.1–3.1)*,† 3.5 (3.3–3.8)*,†,#
Effort recovery (s) 6.0 (5.6–6.5) 0.6 (0.0–1.7)* 4.7 (3.6–5.9)† 5.2 (4.4–6.1)† 6.3 (6.1–6.6)†,#
Bout frequency (no/min) 1 every 6.9 min 1 every 192.0 min* 1 every 12.1 min† 1 every 4.5 min*,†,‡ 1 every 14.9 min*,‡,#
Global positioning system (GPS) analysis was completed during 124 training sessions (N = 26 players, totaling 786 training appearances) and 16 matches
(N = 21 players, totaling 104 NRL appearances). Repeated high-intensity efforts: 3 or more maximal acceleration sprint efforts, very-high speed sprint efforts,
and/or tackle efforts with less than 21 s between efforts. Data are means (and 95% confidence intervals).
* Significantly different (p < 0.05) from NRL competition.
† Significantly different (p < 0.05) from traditional conditioning.
‡ Significantly different (p < 0.05) from repeated high-intensity effort activities.
# Significantly different (p < 0.05) from game-based training.
in this positional group, coupled with the fact that, unless
injured, these players are generally required to play the entire
match, emphasizes the importance of high speed running
in outside backs. Conditioning coaches should prioritize the
development of prolonged, high-intensity running ability in
this positional group.
The most significant differences among playing positions
were the high-intensity collision and repeated effort demands
of match-play. Consistent with the findings of others,2,3,24
the hit-up forwards and wide-running forwards performed a
greater absolute amount of moderate and heavy collisions
than the adjustables and outside backs, and were conse-
quentlyengagedinsignificantlymorecollisionsperminuteof
match-play.Hit-upforwardsandwide-runningforwardswere
involved in a collision approximately each minute, while the
adjustables and outside backs were involved in a collision
approximately every 2 min. Hit-up forwards, wide-running
forwards, adjustables, and outside backs performed a heavy
collisionevery2.5,3.3,5,and5 min,respectively.Whilethere
were no differences among positions for the absolute number
of repeated high-intensity effort bouts performed in a match,
the hit-up forwards and wide-running forwards performed
more repeated high-intensity effort bouts per minute of play.
Hit-up forwards completed on average, one repeated high-
intensity effort bout every 4.8 min, while the wide-running
forwards performed on average, one repeated high-intensity
effort bout every 6.3 min. Conversely, repeated high-intensity
effort bouts occurred on average every 7.7 min and 9.1 min
for the adjustables and outside backs, respectively. Collisions
and tackles are widely acknowledged as the most demanding
aspect of rugby league match-play.25 In addition, research
from our laboratory has recently shown that repeated high-
intensity effort exercise (sprinting and tackling) is associated
with greater heart rate and perceived exertion and poorer
sprint performance than repeated-sprint exercise alone,26
demonstrating that the addition of tackling significantly
increases the physiological response to repeated-sprint exer-
cise and has the potential to reduce physical performance.
These findings, coupled with the repeated high-intensity
effort demands, suggest that repeated sprinting and physical
collisionsarenecessarytoadequatelypreparehit-upforwards
andwide-runningforwardsforthedemandsofcompetition,12
while repeated high-speed sprinting is critical for outside
backs.27
A novel aspect of this study was the comparison of group
means with the most extreme demands for each positional

6. T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86 85
group. The greatest total distances covered by the hit-up
forwards, wide-running forwards, adjustables, and outside
backs were 87%, 47%, 98%, and 40% greater than the mean
value for each positional group. Furthermore, during the
most intense passages of match-play, the hit-up forwards per-
formed over 2 collisions each minute, while the adjustables
were engaged in a repeated high-intensity effort bout every
1.4 min. These findings suggest that reporting mean values
alone may underestimate the most intense physical demands
of competition. Consequently, conditioning programs that
are based on these mean values will likely result in play-
ers being underprepared for the most demanding passages of
competition.2
In the present study, traditional conditioning (i.e., run-
ning without the ball) exceeded the running demands of
National Rugby League competition, but had lower contact
and repeated effort demands than competition. Furthermore,
repeated high-intensity effort training exhibited lower run-
ning demands, and heavy contact demands of competition,
with the duration of efforts in repeated high-intensity effort
bouts also not specific to those performed in competition.
The running, collision, and repeated high-intensity effort
demands of skill training were all lower than competition.
In contrast, game-based training offered the most specific
form of conditioning, exceeding the running demands, and
providing comparable mild, moderate, and overall collision
and repeated high-intensity effort demands to match-play.
These findings demonstrate that game-based training offers
a highly-specific form of conditioning for professional rugby
league players. It has been shown that the magnitude of
fatigue-induced reductions in skill in response to game-
specific repeated high-intensity exercise is reduced in rugby
league players with higher maximal aerobic power.28 Given
these findings, it should be recognized that traditional con-
ditioning (e.g., high-intensity interval running and maximal
aerobic speed training) promotes adaptations that allow play-
ers to perform the other physical demands (e.g., tackling,
collisions, and repeated high-intensity efforts) and skills of
rugby league.28 Equally, the ability to efficiently perform and
recover from repeated high-intensity effort exercise, permits
players to participate in the high-intensity running compo-
nents(e.g.,thekick-chase)ofmatch-play.29 Whilereplicating
the physical demands of competition may facilitate the trans-
fer of physical qualities to the competitive environment, it
should also be acknowledged that exposure to excessive
amounts of highly intense and monotonous training (e.g.,
persistent game-based training) in a non-periodized pro-
gram could potentially result in injury, illness, fatigue, and/or
overtraining.30 Nonetheless, the specific physical demands
of competitive play, especially those demands associated
with collisions and repeated high-intensity efforts, were not
well matched by those observed in traditional conditioning,
repeated high-intensity effort exercise, and skills training
activities, suggesting that modifications may need to be made
to these training activities to better prepare players for the
demands of National Rugby League competition.
5. Conclusion
In conclusion, the results of this study demonstrate that
absolute distances covered during professional rugby league
matches are greater for outside backs, while the collision and
repeated high-intensity effort demands are higher for hit-
up forwards and wide-running forwards. The greatest total
distances covered by the hit-up forwards, wide-running for-
wards, adjustables, and outside backs were 87%, 47%, 98%,
and 40% greater than the mean value for each positional
group, respectively. Although these findings may be used by
conditioning coaches to develop game- and position-specific
training programs for professional rugby league players, it
should be noted that the data were collected from one NRL
club. Consequently, the results may be influenced by the play-
ing roster and individual coaching philosophies and may not
be generalizable to all rugby league clubs. Further studies,
on a larger sample are required to verify these findings.
Practical implications
• Exposure to repeated high-intensity effort exercise (in the
form of repeated sprinting and tackling) should occur
within the conditioning programs of hit-up forwards and
wide-running forwards.
• Conditioning programs for outside backs should focus on
the development of prolonged, high-intensity running abil-
ity.
• Neither traditional conditioning, repeated high-intensity
effort exercise, nor skill training activities match the spe-
cific physical demands of rugby league match-play, while
game-based training offers the most specific form of con-
ditioning.
Acknowledgements
No sources of funding were used to assist this study. The
authors have no conflicts of interest that are directly relevant
to the content of this study.
References
1. Spencer M, Bishop D, Dawson B, et al. Physiological and metabolic
responses of repeated-sprint activities: specific to field-based team
sports. Sports Med 2005;35:1025–44.
2. Austin DJ, Gabbett TJ, Jenkins DG. Repeated high-intensity exercise
in professional rugby league. J Strength Cond Res 2010;25:1898–904.
3. King T, Jenkins D, Gabbett T. A time-motion analysis of professional
rugby league match-play. J Sports Sci 2009;27:213–9.
4. Meir R, Arthur D, Forrest M. Time motion analysis of professional
rugby league: A case study. Strength Cond Coach 1993;1:24–9.
5. Meir R, Colla P, Milligan C. Impact of the 10-meter rule change on
professional rugby league: implications for training. Strength Cond J
2001;23:42–6.

7. 86 T.J. Gabbett et al. / Journal of Science and Medicine in Sport 15 (2012) 80–86
[6]. Spencer M, Lawrence S, Rechichi C, et al. Time-motion analysis of
elite field hockey, with special reference to repeated-sprint activity. J
Sports Sci 2004;22:843–50.
7. Gabbett TJ, Mulvey MJ. Time-motion analysis of small-sided training
games and competition in elite women soccer players. J Strength Cond
Res 2008;22:543–52.
8. Sirotic AC, Coutts AJ, Knowles H, et al. A comparison of match
demands between elite and semi-elite rugby league competition. J
Sports Sci 2009;27:203–11.
9. Sykes D, Twist C, Hall S, et al. Semi-automated time-motion anal-
ysis of senior elite rugby league. Int J Perform Anal Sport 2009;9:
47–59.
10. Gabbett TJ. GPS analysis of elite women’s field hockey training and
competition. J Strength Cond Res 2010;24:1321–4.
11. Jennings D, Cormack S, Coutts AJ, et al. The validity and reliability of
GPS units in team sport specific running patterns. Int J Sports Physiol
Perform 2010;5:328–41.
12. Gabbett T, Jenkins D, Abernethy B. Physical collisions and injury
during professional rugby league skills training. J Sci Med Sport
2010;13:578–83.
13. Boyd LJ, Ball K, Aughey RJ. The reliability of MinimaxX accelerom-
eters for measuring physical activity in Australian football. Int J Sports
Physiol Perform; in press.
14. Gabbett TJ. Training injuries in rugby league: an evaluation of
skill-based conditioning games. J Strength Cond Res 2002;16:
236–41.
15. Buchheit M, Laursen PB, Kuhnle J, et al. Game-based training in young
elite handball players. Int J Sports Med 2009;30:251–8.
16. Hill-Haas S, Coutts AJ, Dawson B, et al. Generic vs small-sided game
training in soccer. Int J Sports Med 2009;30:636–42.
17. Impellizzeri FM, Marcora SM, Castagna C, et al. Physiological and
performance effects of generic versus specific aerobic training in soccer
players. Int J Sports Med 2006;27:483–92.
18. Stone NM, Kilding AE. Aerobic conditioning for team sport athletes.
Sports Med 2009;39:615–42.
19. Aughey RJ, Falloon C. Real-time versus post-game GPS data in team
sports. J Sci Med Sport 2010;13:348–9.
20. Aughey RJ. Australian football player work rate: evidence of fatigue
and pacing? Int J Sports Physiol Perform 2010;5:394–405.
21. Petersen C, Pyne D, Portus M, et al. Validity and reliability of GPS units
to monitor cricket-specific movement patterns. Int J Sports Physiol
Perform 2009;4:381–93.
22. Batterham AM, Hopkins WG. Making meaningful inferences about
magnitudes. Int J Sports Physiol Perform 2006;1:50–7.
23. Cohen J. Statistical power analysis for the behavioural sciences. 2nd
ed. Academic Press: New York; 1969.
24. Gabbett TJ, Jenkins DG, Abernethy B. Physical collisions and injury in
professional rugby league match-play. J Sci Med Sport 2011;14:210–5.
25. Brewer J, Davis J. Applied physiology of rugby league. Sports Med
1995;20:129–35.
26. Johnston R, Gabbett TJ. Repeated-sprint and effort ability in rugby
league players. J Strength Cond Res; in press.
27. Gabbett TJ. Sprinting patterns of National Rugby League competition.
J Strength Cond Res; in press.
28. Gabbett TJ. Influence of fatigue on tackling technique in rugby league
players. J Strength Cond Res 2008;22:625–32.
29. Balsom PD, Seger JY, Sjodin B, et al. Maximal-intensity intermittent
exercise: effect of recovery duration. Int J Sports Med 1992;13:528–33.
30. Gabbett TJ, Jenkins DG. Relationship between training load and injury
in professional rugby league players. J Sci Med Sport 2011;14:204–9.