Physiological and anthropometric characteristics of amateur rugby league players
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Br J Sports Med 2000;34:303–307 303
Physiological and anthropometric characteristics
of amateur rugby league players
Tim J Gabbett
Abstract Rugby league is a body contact sport played at
Objectives—To investigate the physiologi- amateur, semiprofessional, and professional
cal and anthropometric characteristics of levels.1 2 A typical senior rugby league match
amateur rugby league players. lasts 60–80 minutes, with frequent intense
Methods—Thirty five amateur rugby bouts of running and tackling, interspersed
league players (19 forwards and 16 backs) with short bouts of recovery.2–5 Hence, rugby
were measured for height, body mass, league is physically demanding, requiring play-
percentage body fat (sum of four skin- ers to draw upon a variety of fitness compo-
folds), muscular power (vertical jump), nents including (but not limited to) aerobic
speed (10 m and 40 m sprint), and power,6–8 speed,6–9 and muscular power.10–12
maximal aerobic power (multistage fit- Investigations of professional rugby league
ness test). Data were also collected on players have reported mean 10 m and 40 m
match frequency, training status, playing sprint times of 1.71 seconds and 5.32 seconds
experience, and employment related respectively.10 Estimates of maximal aerobic
physical activity levels. power (V ~ O2MAX) have been in the range
Results—The 10 m and 40 m sprint, verti- 48.6–67.5 ml/kg/min.7 9 13 14 Despite having
contrasting matchplay activities,15 the physi-
cal jump, percentage body fat, and multi-
ological profile of professional rugby league
stage fitness test results were 20–42%
forwards and backs is remarkably similar,9 14
poorer than previously reported for
suggesting that fitness training for professional
professional rugby league players. Com-
rugby league is uniform for all positions.9
pared with forwards, backs had signifi- Indeed, most studies have reported similar
cantly (p0.05) between forwards rugby league players. Therefore, the purpose of
Physiotherapy and and backs. At the time of the field testing, this study was to investigate the physiological
Exercise Science, players had participated, on average, in and anthropometric characteristics of amateur
Faculty of Health one 60 minute match every eight days. rugby league players.
Sciences, GriYth
University Gold Coast, Conclusions—The physiological and an-
Queensland, Australia thropometric characteristics of amateur
T J Gabbett rugby league players are poorly devel- Methods
oped. These findings suggest that position SUBJECTS
Correspondence to:
specific training does not occur in ama- Thirty five healthy men with a mean (SD) age
T J Gabbett, School of of 26.5 (5.1) years volunteered for this study.
Physiotherapy and Exercise teur rugby league. The poor fitness of
Science, Faculty of Health non-elite players may be due to a low All subjects were registered players from the
Sciences, GriYth University
playing intensity, infrequent matches of same amateur rugby league competition and
Gold Coast, PMB50 Gold were not receiving training or match payments.
Coast Mail Centre, short duration, and/or an inappropriate
Queensland, Australia 9726 training stimulus. Before participation, each subject successfully
email: (Br J Sports Med 2000;34:303–307) completed a thorough health risk screening
t.gabbett@mailbox.gu.edu.au process20 without any clinically significant find-
Accepted for publication Keywords: conditioning; fitness; non-elite; training; ings. All subjects received a clear explanation of
10 March 2000 rugby the study, including the risks and benefits of
www.bjsportmed.com304 Gabbett
participation, and written consent was ob- the nearest 0.1 kg using analogue scales (Seca,
tained. The GriYth University ethics com- Hamburg, Germany).
mittee approved all experimental procedures.
MUSCULAR POWER
PROCEDURE
Lower leg muscular power was evaluated by the
All field testing was conducted during the vertical jump test.21 A board covering a 150 cm
competitive phase of the rugby league season7 vertical distance was mounted to a wall during
by an independent investigator who was not the vertical jump test. Subjects were requested
aYliated with any of the registered teams. Fol- to stand with feet flat on the ground, extend
lowing approval from the administrators of the their arm and hand, and mark with chalk, the
amateur rugby league competition, team highest point reached. After assuming a crouch
coaches and/or managers were contacted by position, each subject was instructed to spring
the investigator to determine their willingness upward and touch the wall mounted board at
to participate in the study. Three of the four the highest possible point. Vertical jump height
registered teams volunteered to participate, was calculated as the distance from the highest
with the fourth team withdrawing because of point reached during standing and the highest
players’ employment commitments. A mutual point reached during the vertical jump. Vertical
time was then arranged for conducting the field jump height was measured to the nearest 0.1
testing. Coaches stated that they were prepared cm with the average value obtained from two
to devote one training session (about 90 trials used as the vertical jump score. The
minutes) to the field testing. While considera- intraclass correlation coeYcient for test-retest
tion was given to the specificity of the field test, reliability24 and technical error of
the selection of tests included in the field test- measurement25 for the vertical jump test were
ing battery was influenced by this time 0.93 and 4.54% respectively.
constraint.
SPEED
The speed of subjects was evaluated with a 10
FIELD TESTING BATTERY
m and 40 m sprint7 using electronic timing
Standard anthropometry (height, body mass, gates (Speed Light model TB4, serial no
and sum of four skinfolds), speed (10 m and 40 4921001; Southern Cross University Technical
m sprint),7 9 muscular power (vertical jump),21 Services, Lismore, Australia). The timing gates
and maximal aerobic power (multistage fitness were positioned 10 m and 40 m cross wind
test)22 were the field tests selected. Subjects also from a predetermined starting point. On the
completed a brief questionnaire documenting command, subjects sprinted from a standing
match frequency, training status, playing start.14 They were instructed to run as quickly
experience, and employment related physical as possible along the 40 m distance. Speed was
activity levels. All subjects had performed the measured to the nearest 0.01 second with the
experimental procedures on a number of occa- average value obtained from two trials used as
sions before the field testing session. Players the speed score. The intraclass correlation
were requested to refrain from strenuous exer- coeYcient for test-retest reliability24 and tech-
cise for at least 48 hours before the field testing nical error of measurement25 for the 10 m and
session. At the beginning of the field testing 40 m sprint tests were 0.86 and 0.89 and
session, subjects were randomly allocated to 2.31% and 1.52% respectively.
two groups, consisting of approximately equal
numbers of forwards and backs. Subjects in MAXIMAL AEROBIC POWER
group 1 were measured for height and body Maximal aerobic power was assessed using the
mass while sum of skinfolds were recorded for multistage fitness test.22 Subjects were required
group 2. Measurements of muscular power and to run back and forth—that is, shuttle run—
speed were conducted in a similar manner, along a 20 m track, keeping in time with a
with group 1 performing the vertical jump and series of audible signals on a cassette. Each
group 2 performing the 10 m and 40 m sprint. minute, the frequency of the audible signals
At the completion of anthropometric, speed, (and hence running speed) was progressively
and muscular power tests, the field testing ses- increased, until subjects reached volitional
sion was concluded with subjects performing exhaustion. V ~ O2MAX was estimated using
the multistage fitness test (maximal aerobic regression equations described by Ramsbot-
power). tom et al.26 When compared with treadmill
determined V ~ O2MAX, it has been shown that the
ANTHROPOMETRY multistage fitness test provides a valid estimate
As an estimate of body fat, skinfold thickness of maximal aerobic power.26
was measured at four sites using a Harpenden
skinfold caliper. Biceps, triceps, subscapular, COACH QUESTIONNAIRE
and suprailiac on the right side were the four Coaches were requested to complete a brief
sites selected. The exact positioning of each questionnaire documenting the training time
skinfold measurement was in accordance with devoted to the development of muscular
procedures described by Draper et al.21 Per- power, speed, and aerobic fitness. Coaches
centage body fat was calculated from skinfold were also asked to document the training time
measurements using the procedures outlined devoted specifically to rugby league skills
by Durnin and Womersley.23 Height was involving (a) continuous physical activity—for
measured to the nearest 0.1 cm using a example, tackling drills, attacking plays—or (b)
stadiometer, and body mass was measured to no physical activity—for example, team discus-
www.bjsportmed.comFitness of amateur rugby league players 305
Table 1 Anthropometric characteristics of amateur rugby league forwards and backs significantly heavier (p0.05)
Forwards Backs
between forwards and backs with respect to
Age (years) 28.6 (26.7–30.5) 24.2 (21.7–26.7)* height, sum of skinfolds, or estimated body fat.
Height (cm) 178.4 (174.5–182.3) 178.0 (175.4–180.6)
Mass (kg) 90.8 (86.2–95.4) 79.7 (74.7–84.7)*
Sum of four skinfolds (mm) 52.4 (45.8–59.0) 46.1 (37.0–55.2) MUSCULAR POWER, SPEED, AND MAXIMAL
Estimated body fat (%) 19.9 (18.2–21.6) 17.5 (15.0–20.0) AEROBIC POWER
Values are reported as means (95% CI). Table 2 gives the results of the muscular power
*p0.05) be-
Values are reported as means (95% CI). tween forwards and backs. Although backs
*p306 Gabbett
Table 5 Frequency of matches for amateur rugby league forwards and backs respective values for the 10 m sprint, 40 m
sprint, vertical jump, and percentage body fat
Forwards Backs
were 34%, 20%, 30%, and 31% poorer than
Fixture matches played (number) 4.4 (3.8–5.0) 4.6 (4.0–5.2) previously reported for professional rugby
Match frequency (number a week) 0.89 (0.84–0.94) 0.86 (0.81–0.91) league players.7 10 It is highly likely that the
Recovery between matches (days) 8.0 (7.6–8.4) 8.2 (7.8–8.6)
elevated percentage body fat contributes to the
Values are reported as means (95% CI). inferior speed and muscular power of amateur
rugby league players by attenuating the power
average, players had participated in one match
to body mass ratio and therefore reducing per-
every eight days (0.87 (0.84 to 0.90) matches a
formance in match specific tasks.31 Alterna-
week) (table 5).
tively, the poor vertical jump, 10 m and 40 m
sprint results, coupled with the training time
Discussion devoted to these fitness components (table 4),
This study investigated the physiological and suggest that fitness training designed to in-
anthropometric characteristics of amateur crease speed and muscular power is not a
rugby league players. When compared with priority in amateur rugby league.
previously published results for professional Consistent with results of professional rugby
players,6 7 9 10 13 14 estimates of maximal aerobic league players,7 14 the present study of amateur
power (38.98 v 67.5 ml/kg/min), 10 m (2.58 v players found that when compared with
1.71 seconds) and 40 m (6.63 v 5.32 seconds) forwards, backs had lower body mass and
speed, and muscular power (38.1 v 54.2 cm) greater speed during a 40 m sprint. However,
were lower, and percentage body fat higher values for muscular and aerobic power and
(18.8% v 13.0 %) in amateur rugby league percentage body fat were similar between
players. Values for percentage body fat, vertical forwards and backs. The finding of superior 40
jump, 10 m sprint, and maximal aerobic power m speed in backs would be expected given that
were not significantly diVerent between for- forwards rarely are required to run further than
wards and backs. The results of this study show 10 m in a single bout of intense activity.6 Simi-
that the physiological and anthropometric larly, when compared with backs, forwards
characteristics of amateur rugby league players spend significantly more playing time involved
are poorly developed. Furthermore, these find- in tackles15 and physical collisions,13 28 so it is
ings suggest that position specific training does likely that the larger body mass of forwards
not occur in amateur rugby league. The poor assists in the development of greater impact
fitness of non-elite players may be due to a low forces associated with these events. While some
playing intensity, infrequent matches of short position specific diVerences were detected
duration, and/or an inappropriate training between forwards and backs, these diVerences
stimulus. do not appear to be related to contrasting
This study of amateur rugby league players training patterns (table 4). Rather, these results
found an estimated V ~ O2MAX of 38.98 ml/kg/ suggest that position specific training does not
min, a value 20–42% lower than previously occur in amateur rugby league and, as with
reported for professional rugby league professional rugby league, fitness training
players.7 13 Furthermore, the estimated V ~ O2MAX appears to be uniform for all positions.9
was lower (≈20%) than regional (and national) At the time of the field testing, the amateur
representative rugby league players following rugby league players were participating (on
six weeks of detraining.27 The observation of average) in approximately one rugby league
poor aerobic fitness in the present sample of match every eight days (range 7–9 days). In
amateur rugby league players is to be expected, addition, compared with professional rugby
given that the training status of subjects was league,1 5 15 28 29 the duration of matches was
also poor (3.5 hours a week). Indeed, the train- relatively short (60 v 80 minutes). Given that
ing status of the amateur rugby league players the greatest physiological adaptation would be
was about 30–53% lower than recently re- expected to occur in response to playing rugby
ported for professional rugby league players league,15 the poor physical fitness of the
(5.0–7.5 hours a week).28 29 Furthermore, the amateur rugby league players is to be expected.
training time spent in aerobic activities was also Indeed, the poor physiological and anthropo-
considerably lower than currently recom- metric characteristics of the present sample of
mended for the development and maintenance amateur rugby league players may be attrib-
of aerobic fitness.30 It could therefore be uted, at least in part, to infrequent matches of
suggested that the duration of the training short duration and the lower playing intensity
stimulus employed by amateur rugby league at the non-elite level.5 28 The present study
players was inadequate to induce significant investigated rugby league players who com-
peripheral and/or central adaptations for im- peted within the same amateur rugby league
provements in V ~ O2MAX. Alternatively, the low competition. It is possible that players from
estimated V ~ O2MAX in the amateur rugby league other amateur rugby league competitions, who
players of this study suggests that the volume play more matches of longer duration, may
and intensity of training may diVer between have superior fitness to the amateur players of
amateur and professional rugby league. the present study. In addition, it is possible
When compared with professional that, had the present sample of amateur players
competitors,7 the present study found that been regularly competing in matches of longer
measurements of speed and muscular power duration, or tested after developing a greater
were lower, and percentage body fat higher, in degree of match fitness, the physiological and
amateur rugby league players. Indeed, the anthropometric characteristics obtained may
www.bjsportmed.comFitness of amateur rugby league players 307
have been superior to the present findings. 6 Meir R. Evaluating players fitness in professional rugby
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Sport 1997;14:83–101.
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pometric characteristics between elite and players [abstract]. J Sports Sci 1995;13:505.
non-elite competitors. 10 Baker D, Nance S. The relation between running speed and
measures of strength and power in professional rugby
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studies.6 9 10 14 27 However, compared with the put of rugby forwards during maximal treadmill sprinting.
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Take home message
This study has found that the physiological and anthropometric characteristics of amateur
rugby league players are poorly developed. Estimates of maximal aerobic power, speed, and
muscular power were considerably lower than previously reported for professional rugby
league players. These results suggest that amateur rugby league players may benefit from
structured strength and conditioning programmes.
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