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2019
VOLUME 27 | ISSUE 05
ISSN - 1836-649X (online)
WWW.STRENGTHANDCONDITIONING.ORG
AUSTRALIAN STRENGTH AND CONDITIONING ASSOCIATION
JASC | Journal of Australian Strength and Conditioning
ASCA | Ensuring excellence in strength and conditioning
2
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JASC | Journal of Australian Strength and Conditioning
ASCA | Ensuring excellence in strength and conditioning
14
Investigating the role of anthropometric and physical performance measures on team selection in elite and sub-elite under-20 Gaelic football
players. Journal of Australian Strength & Conditioning. 27(05):14-24, 2019 © ASCA.
Original Scientific Research Study
INVESTIGATING THE ROLE OF ANTHROPOMETRIC AND PHYSICAL PERFORMANCE MEASURES ON TEAM
SELECTION IN ELITE AND SUB-ELITE UNDER-20 GAELIC FOOTBALL PLAYERS
Tommy J. Mooney1,2, Shane Malone2,3,4, Bryan D. Cullen2, Ian Darragh5,
Stephen Bennett1,2, Kieran Collins3, Phil Price1 & Stephen Patterson1
1St Mary’s School of Sport, Health and Applied Sciences, Twickenham, London.
2Dublin GAA, Parnell Park, Donnycarney, Dublin, Ireland.
3Gaelic Sports Research Centre, Institute of Technology Tallaght, Dublin, Ireland.
4Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
5School of Health and Human Performance, Dublin City University, Dublin, Ireland.
BLUF
Simple physical performance measures can differentiate between elite and sub-elite under 20’s Gaelic football players
but these measures didn’t distinguish elite starting players from those not selected to start the first game of the season.
ABSTRACT
The current study assessed the effect of anthropometry and physical performance measures on selection in under-20
(U20) Gaelic football players. Fifty-four (n = 54) U20 players (40 elite and 14 sub-elite) were assessed for measures of
stature, body mass, sum of 7 skinfolds (SUM), estimated bodyfat percentage (BF%; Withers equation),
countermovement jump (CMJ), standing broad jump (SBJ), reactive strength index (RSI), 5-20m sprint times and Yo-
Yo intermittent recovery test level 2 (YYIRT2). Additionally, back squat, bench press and chin-up estimated 1 repetition
maximums (1RM) and relative strength were assessed. Elite players had significantly less SUM (56.9mm ± 13.6,
79.6mm ± 33.3, 29%) and BF% (10% ± 2.3, 14% ± 5.9, 28%) than sub-elite players. Elite players had significantly better
CMJ (51.0cm ± 7.1, 45.9cm ± 3.3, 11%), SBJ (2.37m ± 0.16, 2.1m ± 0.15, 12%), RSI (1.90 ± 0.38, 1.5 ± 0.33, 24%),
20m speed (2.86s ± 0.09, 2.95s ± 0.10, 3%), YYIRT2 distances (593m ± 200, 483m ± 121, 23%), relative back squat
(1.46 ± 0.19, 1.34 ± 0.20, 9%) and chin-up strength (1.36 ± 0.10, 1.26 ± 0.13, 8%). Following preseason training, thirty-
seven elite players were retested. Players selected (n = 15) to start the first game presented no significant differences
(p > 0.05) pre or post preseason training to those not selected (n = 22). The current findings suggest that BF%, CMJ,
SBJ, RSI, YYIRT2, 20m speed, relative squat and chin-up strength facilitate selection to an elite team and can
distinguish elite and sub-elite players but doesn’t differentiate starters from non-starters. Coaches should prioritise the
development of jumping abilities, speed, fitness and relative strength with developing Gaelic football players.
Key Words - Gaelic games, performance testing, selection, team sport.
INTRODUCTION
Gaelic football is an intermittent team sport, involving high-intensity anaerobic movements (sprinting, accelerating,
decelerating, change of direction, collisions) interspersed with lower intensity aerobic activities (walking and jogging)
(9). During training and match-play, players must kick, catch, hand pass, tackle and block while moving at speed and
evading physical contacts from the opposition (7). Within the playing structure of Gaelic football, sub-elite players
represent their parochial clubs, while elite players are selected to represent their inter-county team (34). Similar to
academies in professional soccer, underage inter-county development teams (U13-20 years) filter talented youngsters
into senior teams (34), the U20 age-grade is the final stage of the Gaelic football athletic development pathway. Currently
players face a particularly busy competition calendar, playing with their club, university and inter-county teams
concurrently (7). Many talented U20 players transition into elite senior squads but the increased training volumes,
running distances and physical demands required to play at the senior level increases the injury risk of these young and
inexperienced players (25). It has been observed that greater physical capacities within athletes reduces the risk of
injury occurrence (37). For example, players with greater repeated sprint ability, speed, lower body strength, higher
aerobic capacity and more playing experience can tolerate larger workloads and have a reduced risk of injury (25). It is
generally assumed that physical capacity improves as athletes mature (40), but limited evidence surrounding the
physical capacity of U20 players makes this hypothesis unclear within Gaelic football populations.
Majority of the research analysing Gaelic football documents elite senior inter-county Gaelic footballer players but the
U20 population remains unexamined. Therefore, coaches at the U20 level are forced to infer physical performance
standards from senior data or similarly aged players from other team sports such as Australian football, rugby or soccer.
Several studies have analysed the anthropometric and physical qualities of elite senior inter-county (20,38), collegiate
(30) and youth (9) players but the U20 age grade is yet to be studied. Assessing the anthropometrical differences
between playing levels can offer valuable insights into the key anatomical qualities that may discriminate elite from sub-
JASC | Journal of Australian Strength and Conditioning
ASCA | Ensuring excellence in strength and conditioning
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elite players (7). Furthermore, examining the physical qualities of U20 Gaelic football players will provide relevant
normative data for S&C coaches who work with this population.
Previously, high-speed running has been shown to distinguish elite from sub-elite players in senior Gaelic football
players. This suggests there may be a minimum level of fitness required to perform at the elite level (7). The Yo-Yo
intermittent recovery test level 2 (YYIRT2), can differentiate between elite and sub-elite soccer (23) and Australian
football (31) players. The YYIRT2 has been studied in elite senior Gaelic football teams (18,20,38), but these data have
yet to be reported in an U20 population. Strength and power are also key determinants of sporting success (39), but
little research has examined measures of maximal strength in elite Gaelic football players (20). Back squat 1 repetition
maximum (1RM) influences team selection in semi-professional rugby league (ES=1.02) (14). Similarly, bench press
strength discriminates between playing levels in elite junior rugby league (r = 0.80) (4) and influences selection to an
elite U18s Australian football team (21). Likewise, Chin-up strength has a large effect on team selection (ES =1.26), in
rugby league (14). These findings combined, suggest that repeated high intensity running ability and neuromuscular
strength qualities may influence selection to elite development squads but the lack of relevant data is a challenge for
coaches.
Sport-specific skills in combination with the necessary physical abilities determines selection to an elite team, comparing
starters to non-starters allows coaches assess the relative importance of physical qualities within a team and highlight
which qualities might influence selection in that team (13,14). Understanding the physical discrepancies between
starters and non-starters will allow coaches to make more informed decisions when selecting players. Researchers
have reported significantly different physical qualities between starters and non-starters in elite junior rugby, soccer and
Australian football teams (13,27,45), but this is currently unexplored in Gaelic football. Starters tend to be older, taller
and leaner than non-starters, while also displaying superior vertical jump abilities, greater leg strength, faster 10-40m
speed times and cover larger distances in the YYIRT2 (13,27,45). Together, these findings suggest that particular
anthropometric and physical qualities may influence selection to elite Gaelic football teams.
Profiling the physical abilities of developing Gaelic football players will provide coaches with normative data, identify
which physical traits develop with age and how these traits may influence selection (40). Till et al. (40), reported that
anthropometry, sprint speed, strength, power and aerobic capacity differentiated between playing levels across all age
grades within rugby league players. Large effect sizes were observed in aerobic power (ES = 0.96) and liner sprint
speeds over 10m (ES = 1.35), 20m (ES = 1.11) and 40m (ES = 0.92) when comparing elite junior rugby league players
to sub-elite players (13), similar results have been presented in youth soccer (15) and elite U18 Australian football (21).
These findings suggest that physical qualities are imperative to playing at an elite level in underage team sports.
Given the above, the aims of this study were twofold, firstly, to determine the differences in preseason physical
performance measures between elite U20 inter-county and sub-elite U20 club level players. Secondly, to determine if
physical performance measures following preseason training might influence selection to start the first game of the
season. It was hypothesised that elite players would present taller and leaner physiques and superior jumping, speed,
fitness and strength abilities in comparison to sub-elite players. Likewise, that starters would exhibit greater physical
abilities than non-starters.
METHODS
Approach to the Problem
The current cross-sectional study investigated the effect of anthropometry and physical performance measures on
selection in U20 Gaelic football players. Prior to preseason training, the physical testing results of elite players were
compared to sub-elite players. Following preseason training, test results of players selected to play the first game of the
season (starters) were compared to those not selected (non-starters). Sixteen anthropometrical and physical tests were
used to compare differences in body mass (kg), stature (cm), sum of 7 skinfolds (mm; SUM), estimated body fat
percentage (BF%; Withers equation), countermovement jump (CMJ; cm), standing broad jump (SBJ; m), reactive
strength index (RSI), linear 5m - 20m speed (s), YYIRT2 (m), 3 repetition maximum (3RM; kg) and relative (Kg·Kg-1)
back squat, bench press and chin-up strength.
Subjects
Forty elite U20 (mean ± SD age; 19.1 ± 0.6 years) and fourteen sub-elite U20 (19.2 ± 0.5 years) Gaelic football players
participated in this study. All elite players were members of the same U20 inter-county squad. All sub-elite players were
club level players invited for trials to the elite squad. Following 8 weeks of preseason training, all injury free elite players
were retested under the original testing procedures and conditions to compare starters (n = 15) and non-starters (n =
22). Following ethical approval from the St Mary’s School of Sport, Health and Applied Sciences, Twickenham, all eligible
participants read and signed an informed consent form detailing the testing procedures, benefits and potential risks
associated with the study. All participants were informed that they could withdraw from the study at any time and received
detailed individualised feedback post-testing. Furthermore, all subjects completed a subjective wellness questionnaire
prior to testing to evaluate subjective well-being and readiness to perform. To be eligible for inclusion in this study, all
players were required to complete all initial anthropometric and performance tests, have five years Gaelic football playing
experience, be over 18 years old, be deemed injury free and fit to perform by the team physiotherapist.
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ASCA | Ensuring excellence in strength and conditioning
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Procedures
All players completed the initial testing sessions on the same days and each testing battery was conducted over 2 days
and separated by 48 hrs to limit accumulated fatigue effects. All testing and data collection was led by the lead
researcher and took place indoors and at roughly the same time of day (17:00 – 21:00) to minimise external interferences
and the influence of circadian rhythm variations on performance (11). Day 1 took place in a sports hall on a wooden
sprung floor and day 2 in a University high-performance gym. Players were asked to refrain from intense physical
exercise between testing sessions and the 24 hours prior to the initial testing session. Participants were allowed drink
fluids and wore suitable sports clothing and footwear during testing. To maximise performance, participants were
instructed to increases the consumption of slow digesting carbohydrates, lean protein and water 24 hours prior to each
testing battery (17). The first testing battery was conducted prior to the beginning of preseason training (January 2018)
and the second battery eight weeks later. After anthropometric assessments, a standardised “RAMP” warmup consisting
of jogging, bodyweight movements and jumping exercises was led by the lead researcher, a UKSCA accredited coach
(19). Tests were conducted in the stated sequence and alternated alphabetically by the first name of the athlete, except
the YYIRT2 and strength testing, which were performed together as a group. This allowed optimal rest between tests
and minimised cumulative fatigue impacting upon performance (33).
Figure 1 – Schematic of testing battery running order.
Anthropometry
All anthropometric measurements were taken prior to the warm-up and in accordance with the International Society for
the Advancement of Kinanthropometry (ISAK) guidelines (28). Stature was measured to the nearest 0.01 m, using a
stadiometer (Seca model 213, Hamburg, Germany) and body mass to the nearest 0.1 kg using a digital weighing scales
(Seca model 875, Hamburg, Germany). Participants removed footwear, wore minimal clothes and stood in an
anatomically neutral position with the head placed in the Frankfort plane during both measurements. Skinfold thickness
measurement was conducted by a level 2 ISAK accredited tester, using a Harpenden skinfold callipers (Harpenden
Instruments Ltd, England). The total millimetres of subcutaneous fat at seven sites (triceps, biceps, subscapular,
supraspinale, abdominal, front thigh and medial calf) was measured (SUM), each site was measured twice, and the
mean value was used for analysis. The typical error of measurement across the 7 sites was 3% and deemed acceptable
(1). Estimated Body fat percentage was calculated using the Withers equation (43). The intraclass correlation coefficient
(ICC) for stature, body mass and SUM have previously been reported, 0.99, 0.99, and 0.99 respectively (13).
Countermovement Jump
CMJ was used to assess vertical jumping capabilities using an Optojump photocell system (Microgate, Bolzano, Italy).
In accordance with previous testing procedures, participants started in a standing position and were instructed to jump
maximally as if “catching a ball overhead”, while keeping the legs straight during the flight phase and landing with both
feet dorsiflexed (2). Participants were allowed to self-select the level of arm swing, speed and depth of the eccentric
phase. CMJ’s incorporating an arm swing offer a more sport specific movement pattern and allow greater jump heights
(10,24). Participants performed three jumps with a 30s rest interval between jumps and the best jump in centimetres
was used for analysis. The opto-jump system has shown high reliability (ICC = 0.982) and intra-session reliability (ICC
= 0.999) within male cohorts (2).
Standing Broad Jump (SBJ)
The SBJ was performed in line with established methods (9,24,29), subjects stood with toes on the start line,
perpendicular to a standard measuring tape and were instructed to jump for maximal distance, using a simultaneous
countermovement of the upper and lower appendages. Three trials were performed, with a 30s rest interval between
trials and the furthest jump in meters, measured from the heel of the rear foot was used for analysis. The attempt was
retaken if the subject didn’t land in a stable bilateral position. The SBJ is deemed reliable (ICC = 0.95; CV = 2.4%) (29).
JASC | Journal of Australian Strength and Conditioning
ASCA | Ensuring excellence in strength and conditioning
17
Reactive Strength Index (RSI)
Opto-jump propriety software (Opto-jump™ Next software, version 1.12) was used to calculate RSI (jump height in
metres divided by ground contact time in seconds) from a standardised 0.3m drop jump. Participants were instructed to
minimise ground contact time and maximise jump height, avoid jumping down or falling off the box, keep legs straight
during the flight phase and absorb the landing with both feet dorsiflexed. To standardise the protocol and limit upper
body involvement hands had to remain on hips throughout, otherwise the trial was deemed invalid and retaken.
Participants performed 3 attempts, with a 30 second rest period, and the best result was used for analysis. This test is
reliable and was conducted in line with previous testing procedures (ICC = 0.985) (16).
Linear Speed
Linear speed was assessed using an infrared timing system (Brower Timing Systems, Draper, USA) over 5m and 20m
intervals. Distances were marked to the nearest 0.01m using a standard measuring tape and gates were placed at the
start, 5m and 20m markers. Participants started in a stationary position on a start line and were instructed to start when
ready, sprint through the 20m gates as fast as possible, to a coloured cone placed at 25m, to ensure subjects didn’t
decelerate early. Times were recorded to the nearest 0.01 second and the fastest score of three trials was used for
analysis. Participants had a minimum of 3 minutes rest between trials. This test (ICC = 0.95) (38) and equipment shows
high levels of reliability (CV = 1%) (41).
Yo-Yo Intermittent Recovery Test Level 2
The YYIRT2 consists of repeated 2 x 20m shuttles, separated by 10second rest periods, progressively increasing in
speed and was performed in accordance with established testing procedures (23). The audio beeps were played via an
iPhone 6s (Apple Inc., Cupertino, CA, USA) connected to a portable speaker (Turbosound, Partridge Green, United
Kingdom). Failure to reach the line in time resulted in a verbal warning and the test was terminated when a subject failed
to cross the line in time on two successive attempts or by volitional exhaustion. The total meters were recorded at the
cessation of the test. The YYIRT2 has previously been shown to be a reliable measure within team sport cohorts (ICC
= 0.93; CV = 7.1%) (12).
Strength Testing
Strength testing took place 48 hours later and consisted of a 3-repetition maximum (3RM) full depth back squat, bench
press and weighted chin-up. Participants were fully explained the procedures, technical models and had performed the
exercises as part of previous training programmes. Following a standardised bodyweight warmup, participants began
lifting lighter weights for 8, 5 and 3 repetitions before increasing loads to a 3RM. 1 repetition maximums (1RM) were
estimated using a 3RM correction factor (1.08) (3), estimated 1RMs and 1RM relative to body mass were used for
analysis. Participants had a minimum of 3 minutes rest between heavy attempts and 20kg Eleiko weightlifting training
barbells and plates (Eleiko Sport, Halmstad, Sweden) were used for all trials. During the back squat, subjects were
required to “squat below parallel”, ensuring the hip joint passed below the knees before returning to a standing position
by extending the knee and hip joints. For the bench press to be considered a valid trial, participants feet had to remain
in contact with the floor, glutes on the bench and finish the lift with arms fully extended after touching and not bouncing
the barbell off their chest. Participants self-selected the hand spacing during the bench press. The 3RM chin-up was
calculated as the subject’s body mass in addition to the maximum load lifted for three repetitions. Beginning from a still
hanging position, using an underhand grip, participants were instructed to concentrically flex the elbows and pull their
chest to the bar before eccentrically lowering to a fully extended position. Verbal encouragement and loud music were
used to enhance arousal and performances. The 3RM back squat, bench press, weighted chin-up are reliable in team
sport athletes (ICC = 0.93, 0.88 and 0.82, CV = 2.3%, 2.2% and 4.3%) (14).
Training Programme
Following the initial testing session, all players selected to the elite squad trained for 8 weeks following a periodised
concurrent programme. Training during this period consisted of 24 sessions, 13 gym, 8 pitch and 3 matches. Gym
sessions were targeted towards neuromuscular strength and power development and consisted of hang power clean,
back squat, split squat, bench press and chin-up exercises for 3-5 sets of 3-6 repetitions performed at 75-90% 1RM
(32,35), lasting one hour with an average rate of perceived exertion (RPE) of 7. Pitch sessions incorporated Gaelic
specific skills and high intensity interval training (HIT) and were 90 minutes with an average RPE of 7.5. HIT consisted
of 15-second runs performed at 120% of individual maximal aerobic speed and interspersed with 15 seconds of rest for
2-3 sets of 8-12 repetitions (5). To minimise the interference effect, sessions targeting strength or aerobic qualities were
separated by a minimum of 24 hours (36). Players also trained and played with their respective club and university
teams during this period.
Statistical Analysis
Data were analysed using SPSS (Version 24; IBM Corporation, NY, USA) and presented as mean ± standard deviations.
The data were screened for normality using the Shapiro-Wilk test, checked for homogeneity of variance using the
Levine’s test and sphericity using Mauchly's test of sphericity. Data met the assumptions of sphericity and parametric
statistics. An independent t-test was performed to analyse the differences between playing level (elite vs sub-elite)
(independent variables) and the physical performance measures (dependent variables). The repeated measures
ANOVA (2x2) were used to compare the differences in physical qualities pre and post preseason training in starters and
non-starters. Within-subject differences were analysed further using paired sample t-tests. Hedges’ G effect size (ES)
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statistic was used to assess the relative differences between elite vs sub-elite players, starters vs non-starters and pre
vs post preseason performances independent of p values (8). Effect sizes of < 0.2, 0.2, 0.5, and >0.8 were denoted as
trivial, small, moderate, and large, respectively (6). Significance was set at a level of p ≤ 0.05 for all analysis.
RESULTS
The differences in preseason anthropometry and physical testing measures between elite and sub-elite U20 Gaelic
football players are presented in Table 1. Elite players had significantly lower SUM (56.9mm ± 13.6, 79.6mm ± 33.3,
29%, large) and BF% (10% ± 2.3, 14% ± 5.9, 28%, large) than sub-elite players. In addition, elite players had significantly
greater jumping performances CMJ (51.0cm ± 7.1, 45.9cm ± 3.3, 11%, moderate), SBJ (2.37m ± 0.16, 2.1m ± 0.15,
12%, large), RSI (1.90 ± 0.38, 1.5 ± 0.33, 24%, large), faster 20m speed (2.86s ± 0.09, 2.95s ± 0.10, 3%, large), larger
YYIRT2 distances (593m ± 200, 483m ± 121, 23%, moderate), superior relative back squat (1.46 ± 0.19, 1.34 ± 0.20,
9%, moderate) and chin-up strength (1.36 ± 0.10, 1.26 ± 0.13, 8%, large). No significant differences (p > 0.05) were
evident in 5m speed, back squat 1RM, bench 1RM, chin-up 1RM or relative bench press strength and effect sizes
ranged from trivial to moderate (Range: ES = 0.16 - 0.53).
Table 1 - Preseason physical performance measures of elite and sub-elite U20 Gaelic football players.
Elite (n = 40)
Sub-elite (n = 14)
Effect size
Inference
Age (y)
19.10 ± 0.63
19.22 ± 0.55
0.19
Small
Anthropometry
Stature (m)
1.81 ± 0.05
1.81 ± 0.04
0.07
Trivial
Body mass (kg)
78.1 ± 6.6
82.1 ± 9.6
0.54
Moderate
Sum of 7 skinfolds (mm)
56.9 ± 13.6†
79.6 ± 33.3
1.10
Large
Body fat (%)
10.0 ± 2.3†
14.0 ± 5.9
1.09
Large
Jumping Ability
CMJ (cm)
51.0 ± 7.1†
45.9 ± 3.3
0.79
Moderate
SBJ (m)
2.37 ± 0.16†
2.1 ± 0.15
1.58
Large
RSI (m·s-1)
1.90 ± 0.38†
1.5 ± 0.33
0.98
Large
Speed
5m (s)
0.92 ± 0.04
0.94 ± 0.04
0.38
Small
20m (s)
2.86 ± 0.09†
2.95 ± 0.10
0.88
Large
YYIRT2
Distance (m)
593 ± 200†
483 ± 121
0.59
Moderate
Strength
Back squat 1RM (kg)
114 ± 16
109 ± 16
0.29
Small
Back squat RS (kg • kg-1)
1.46 ± 0.19†
1.34 ± 0.20
0.63
Moderate
Bench 1RM (kg)
77 ± 12
75 ± 15
0.16
Small
Bench RS (kg • kg-1)
0.99 + 0.14
0.92 ± 0.15
0.53
Moderate
Chin-Up 1RM (kg)
106 ± 11
103 ± 14
0.22
Small
Chin-Up RS (kg • kg-1)
1.36 ± 0.10†
1.26 ± 0.13
0.89
Large
Values presented as means ± SD.
† Significant differences (p < 0.05) between elite and non-elite players.
Effect sizes of <0.09, 0.10– 0.49, 0.50–0.79, and >0.80 considered trivial, small, moderate, and large, respectively.
CMJ = countermovement jump; SBJ = standing broad jump; RSI = reactive strength index; YYIRT2 = Yo-Yo intermittent recovery test level 2; 1RM =
1 repetition maximum; RS = relative strength.
There were no statistically significant two-way interactions between performance variables and those selected to start
the first game (p > 0.05). Within subject changes in performance variables are presented in Table 2. Following preseason
training, starters significantly improved YYIT2 distances, (544m ± 201, 705m ± 137, 30%, large) and bench press 1RM
(78kg ± 14, 88kg ± 13, 13%, moderate). Non-starters significantly improved YYIT2 distances (627m ± 194, 760m ± 190,
21%, moderate), back squat 1RM (112kg ± 14, 123kg ± 13, 9%, moderate), chin-up 1RM (105kg ± 11, 112kg ± 10, 7%,
moderate) and relative back squat (1.44 ± 017, 1.54 ± 0.17, 7%, moderate) and relative chin-up (1.34 ± 0.11, 1.40 ±
0.09, 4%, moderate) strength.
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ASCA | Ensuring excellence in strength and conditioning
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Table 2 - Pre and post preseason physical qualities of starters and non-starters on an elite U20 Gaelic football team.
Starters
(n = 15)
Non-
starters
(n = 22)
Starters
(n = 15)
Non-
starters
(n = 22)
Pre
Pre
Effect
size
Inference
Post
Post
Effect size
Inference
Age (y)
19.3 ±
0.7
19.0 ±
0.6
0.33
Small
19.4 ±
0.67
19.2 ±
0.59
0.35
Small
Anthropometry
Stature (m)
1.82 ±
0.1
1.81 ±
0.05
0.09
Trivial
1.82 ±
0.06
1.81 ±
0.05
0.06
Trivial
Body mass (kg)
78.6 ±
7.8
78.0 ±
5.5
0.09
Trivial
80.6 ±
7.1
79.8 ±
5.4
0.12
Small
Sum of 7 skinfolds (mm)
53.5 ±
8.8
58.7 ±
15.9
0.38
Small
52.6 ±
8.2
57.3 ±
16.9
0.33
Small
Body fat (%)
10.2 ±
3.0
10.0 ±
2.0
0.38
Small
9.3 ±
1.4
10.1 ±
2.9
0.33
Small
Jumping Ability
CMJ (cm)
53.3 ±
7.5
50.2 ±
6.8
0.42
Small
54.7 ±
7.0
50.4 ±
6.5
0.63
Moderate
SBJ (m)
2.41 ±
0.15
2.37 ±
0.17
0.27
Small
2.47 ±
0.18
2.37 ±
0.16
0.54
Moderate
RSI (m·s-1)
2.02 ±
0.35
1.88 ±
0.37
0.38
Small
1.90 ±
0.31
1.82 ±
0.37
0.22
Small
Speed
5m (s)
0.92 ±
0.03
0.92 ±
0.04
0.23
Small
0.91 ±
0.03
0.90 ±
0.03
0.13
Small
20m (s)
2.82 ±
0.09
2.88 ±
0.08
0.64
Moderate
2.85 ±
0.08
2.87 ±
0.08
0.29
Small
YYIRT2
Distance (m)
544 ±
201
627 ±
194
0.41
Small
705 ±
137*
760 ±
190*
0.31
Small
Strength
Back squat 1RM (kg)
116 ±
20
112 ±
14
0.24
Small
126 ±
18
123 ±
13*
0.25
Small
Back squat RS
(kg • kg-1)
149 ±
0.22
1.44 ±
0.17
0.26
Small
1.58 ±
0.23
1.54 ±
0.17*
0.18
Small
Bench 1RM (kg)
78 ±
14
78 ±
11
0.02
Trivial
88 ±
13*
84 ±
11
0.37
Small
Bench RS (kg • kg-1)
1.00 ±
0.16
1.00 ±
0.13
0.03
Trivial
1.09 ±
0.12
1.05 ±
0.12
0.36
Small
Chin-Up 1RM (kg)
109 ±
12
105 ±
11
0.38
Small
115 ±
11
112 ±
10*
0.32
Small
Chin-Up RS (kg • kg-1)
1.39 ±
0.10
1.34 ±
0.11
0.46
Small
1.43 ±
0.08
1.40 ±
0.09*
0.34
Small
Values presented as means ± SD.
† Significant differences (p < 0.05) between starters and non-starters.
* Significant differences (p < 0.05) between pretests and posttests.
Effect sizes of <0.09, 0.10– 0.49, 0.50–0.79, and >0.80 considered trivial, small, moderate, and large, respectively.
CMJ = countermovement jump; SBJ = standing broad jump; RSI = reactive strength index; YYIRT2 = Yo-Yo intermittent recovery test level 2; 1RM =
1 repetition maximum; RS = relative strength.
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ASCA | Ensuring excellence in strength and conditioning
20
The statistically significant changes in the elite squad’s performance measures following preseason training are
presented in Figures 2-4. The elite squad significantly improved YYIRT2 distances (+144m ± 131, 24%, moderate), back
squat 1RM (+10kg ± 7, 24%, moderate), bench press 1RM (+7kg ± 7, 9%, moderate), chin-up 1RM (+7kg ± 5, 6%,
moderate) and relative back squat (+0.09 ± 0.09, 6%, small), relative bench press (+0.07 ± 0.08, 7%, moderate) and
relative chin-up (+0.05 ± 0.06, 4%, moderate) strength respectively. There were no significant changes (p > 0.05) in any
other performance measure and effects sizes ranged from trivial to small (Range: ES = 0.02 - 0.29).
† Significant differences (p < 0.05) between pre-tests and post-tests.
ES = Effect sizes; YYIRT2 = Yo-Yo intermittent recovery test level 2.
Figure 2 – Changes in elite players repeated high-intensity running after 8 weeks of preseason training (n = 37).
Values presented as means ± SD.
Values presented as means ± SD. † Significant differences (p < 0.05) between pre-test and post-test.
ES = Effect sizes; 1RM = 1 repetition maximum.
Figure 3 – Changes in elite players maximal strength after 8 weeks of preseason training (n = 37).
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ASCA | Ensuring excellence in strength and conditioning
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Values presented as means ± SD. † Significant differences (p < 0.05) between pre-test and post-test.
ES = Effect sizes; RS = relative strength.
Figure 4 – Changes in elite players relative strength after 8 weeks of preseason training (n = 37).
DISCUSSION
The aims of the current study were to determine the differences in preseason physical performance measures between
elite U20 inter-county and sub-elite U20 club level players. Furthermore, to determine if physical performance measures
following preseason training might influence selection to start the first game of the season. This study is the first to profile
the preseason anthropometric and physical performance test results of U20 Gaelic football players and compare the
physical qualities of an elite squad to age-matched sub-elite players. The findings presented may help coaches
determine which physical qualities may contribute or hinder elite performance. The primary findings were that significant
differences are evident in anthropometry and physical performance measures between those selected to an elite U20
Gaelic football squad and those not selected (i.e. sub-elite). The results demonstrate that elite U20 Gaelic football
players are more powerful, leaner, faster, fitter and stronger than sub-elite players, suggesting that these physical
characteristics may facilitate playing at the elite level. Interestingly, there were no significant differences between starters
and non-starters in any anthropometric or physical performance measure, suggesting that once players develop elite
level physical qualities, alternative skills and attributes contribute to team selection.
It was observed that elite players were significantly leaner than sub-elite players but not significantly different in body
mass or stature. The findings support previous research which suggested that lean muscle mass discriminates elite
from sub-elite Gaelic football players (7). This lean predisposition may contribute to other physical qualities and influence
the superior jumping performances, faster sprint speeds and greater relative strength seen in the elite players.
Therefore, coaches should endeavour to optimise body composition through training practices and nutritional strategies,
these may include consistent educational work-shops, goal setting for players with regard to body composition and
nutritional preparedness for training and match-play (7). Although there were no differences in stature between elite and
sub-elite players, elite players had significantly better jumping abilities and reactive strength than sub-elite players.
These findings are consistent with elite and sub-elite junior rugby league players (13) and highlight the importance of
lower body power and reactive qualities in intermittent team sports. These superior performances may be attributed to
the importance of jumping and catching in Gaelic football. Shovlin (38) hypothesised that the requirement to frequently
contest aerial balls influenced greater vertical jumping abilities in Gaelic football players. With such a high priority placed
on this specific skill set, it’s logical that elite players demonstrate greater explosiveness (RSI), vertical (CMJ) and
horizontal (SBJ) jumping abilities.
In addition to explosive qualities, the physical demands of Gaelic football require well-developed endurance and strength
qualities (26). As hypothesised, elite U20 players presented significantly different YYIRT2 performances to sub-elite
players, suggesting performance at the elite level requires superior levels of conditioning. Interestingly, absolute strength
in the back squat, bench press and chin-ups were not significantly different between elite and sub-elite players. However,
significant differences were evident in relative lower (back squat) and upper body (chin up) strength. Relative back squat
strength relates to greater power and speed qualities in elite academy rugby league (22) but is unexamined in Gaelic
football. Back squat strength has a strong correlation with jump and speed tasks and may have contributed to the elite
players superior speed and jumping abilities (42). These findings are consistent with previous literature, where it has
been demonstrated that endurance, strength and power characteristics influence selection to elite junior rugby league
(13), soccer (15) and Australian football (21) teams.
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This study reports the physical testing performances of those selected to start the first game of the season (starters)
with those not selected (non-starters). Starters were taller, heavier, leaner and had superior performances in all tests
except 5-m sprint and YYIRT2, suggesting physical qualities may have a minor effect on selection but there were no
statistically significant differences in any variable when compared to non-starters pre and post preseason training (Table
2). Similar to the findings presented in this study, vertical jump, lower and upper body strength were non-significant
between starters and non-starters in an elite Australian football team (45). The results imply that physical qualities are
homogeneous among elite U20 Gaelic football players, suggesting that Gaelic football-specific skills, decision making
and playing ability influences a manager’s decision when selecting the starting team.
During the observed 8-week training period, some players were required to play with their respective club or university
teams, thus limiting any standardisation of training loads. Furthermore, without a control group, it is difficult to make
meaningful inferences regarding the effects of the training programme on physical adaptations. Despite this, YYIRT2
distances improved following preseason training (24%) (Figure 2) and the improvements in this study are in line with
previously reported improvements in elite senior Gaelic football players, 31% (18) and 18% (38) respectively. The
YYIRT2 scores reported in this study are lower than previously reported distances in elite senior players (985 - 1587m)
(18,20,38) and suggests that repeated high-intensity intermittent running ability increases with age and playing
experience (25). Although it must be noted, the preseason YYIRT2 scores reported are expected to increase further,
over the course of the season (18,38). Additionally, all measures of absolute strength (Squat 1RM = 9%, Bench 1RM =
9%, Chin-up 1RM = 6%) and relative strength (Squat = 6%, Bench = 7%, Chin-up = 4%) concurrently improved.
Likewise, professional soccer players made significant improvements in half back squat 1RM, bench press 1RM and
YYIRT2 performances following an 8-week preseason concurrent training programme consisting of muscular strength
training and high-intensity interval running (44). These findings suggest that elite team sports athletes can concurrently
improve contrasting qualities during the preseason, provided training is organised appropriately.
In summary, the current study is the first to profile the anthropometric and physical performances measures of U20
Gaelic football players and found significant differences in preseason results between elite and sub-elite players. Body
fat, jumping distances, explosiveness, speed, high intensity running ability and relative strength all improved with playing
level. No significant differences were evident between starters and non-starters but, after 8 weeks of preseason training,
elite players significantly improved YYIRT2 distances, back squat 1RM, bench press 1RM, chin-up 1RM and relative
back squat, bench press strength respectively. This study found that specific physical tests (body fat, CMJ, SBJ, RSI,
20m speed, YYIRT2 distance, back squat and chin-up relative to bodyweight) can differentiate between elite and sub-
elite players. Although, these physical tests didn’t discriminate starters from non-starters. The findings presented in this
study suggest lean muscle mass, power, speed, endurance and relative strength qualities facilitate playing at the elite
level and effect squad selection. Once these physical attributes are present, the ability to execute Gaelic specific skills
under pressure and in-game conditions dictate who is selected to start on an elite U20 Gaelic football team. The results
presented may offer normative standards for coaches, but this study only presents the results of one elite U20 squad
and should be interpreted accordingly. A standardised battery of fitness tests conducted with larger sample sizes, over
multiple seasons with several teams and age grades will provide further insight regarding the effect of physical
performance measures on team selection in Gaelic football.
PRACTICAL APPLICATIONS
Strength and conditioning coaches working with U20 Gaelic football players should use physical testing results to
ascertain the physical discrepancies within the squad and inform training practices. Players with underdeveloped
jumping abilities, speed, fitness and relative strength qualities may be limiting their potential to play at the highest level,
therefore, coaches should prioritise the enhancement of these qualities in Gaelic football strength and conditioning
programmes. Table 3 presents the physical qualities of one elite U20 Gaelic football team and provides coaches with
normative data and age specific benchmarks. The demanding fixture schedule in elite Gaelic football may limit the
contact time strength and conditioning coaches have with athletes, therefore, the development of relative strength and
aerobic fitness should be emphasised during the preseason period. A concurrent muscular strength and high-intensity
running programme can improve strength and endurance measures but contrasting qualities should be emphasised on
separate days. Strength and conditioning coaches should liaise with skill coaches to create a training programme that
incorporates the development of both Gaelic football skills and physical qualities, this may produce a synergistic effect
and facilitate a larger transfer of physical qualities to game performances.
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Table 3 - Post preseason physical qualities of an elite U20 Gaelic football team (n = 37).
Minimum
Maximum
Anthropometry
Stature (m)
1.71
1.93
Body mass (kg)
69.8
92.0
Sum of 7 skinfolds (mm)
35.8
104.2
Body fat (%)
6
18
Jumping Ability
CMJ (cm)
40.8
68.8
SBJ (m)
2.14
2.82
RSI (m·s-1)
1.28
2.60
Speed
5m (s)
0.84
0.96
20m (s)
2.71
3.04
YYIRT2
Distance (m)
480
1160
Strength
Back squat 1RM (kg)
95
162
Back squat RS (kg • kg-1)
1.13
2.00
Bench 1RM (kg)
65
113
Bench RS (kg • kg-1)
0.75
1.31
Chin-Up 1RM (kg)
97
137
Chin-Up RS (kg • kg-1)
1.27
1.64
CMJ = countermovement jump; SBJ = standing broad jump; RSI = reactive strength index; YYIRT2 = Yo-Yo intermittent recovery test level 2; 1RM =
1 repetition maximum; RS = relative strength.
Disclosure
The authors would like to thank all the participants and management of the team who participated in the current
investigation. The authors declare that they have no conflicts of interest.
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