Effects of Re-Warming Up at Half Time on Gaelic Footballers

QUESTION

HALF TIME RE-WARMUP MAINTAINS SECOND HALF PERFORMANCE CAPACITY IN MALE SENIOR CLUB GAELIC FOOTBALL PLAYERS.

1.1 Aims and objectives

To my knowledge this piece will be the first of its kind in this particular sport.  The primary aim of this study is to determine the effects of re warming up a team of club level Gaelic footballers at half time.  Three different 7 minute re warm up routines will be used 1. Control  group (CON) 2. Aerobic warm –up group (AER)  and 3. A dynamic warm up group (DYN), placed at the end of half time period. We will be investigating what effect these interventions have on power output immediately before the second half resumes. We hypothesise that 1) both routines will be superior to rest and 2) that 7 mins of aerobic warm-up activities  will be equally as effective as a standard dynamic warm –up of the same time frame on second half performance.

Objectives

1. To investigate the impact a half time warm-up has on power output for the second period.
2. To prove that either or both of my suggested warm-up protocols (aerobic- dynamic) are superior to rest.
3. To investigate which of my proposed warm-up protocols (aerobic- dynamic) is the most beneficial in regards to power output and hence readiness for the second half.
4. To investigate whether there is a power output drop after playing the first half of a senior club level Gaelic football match.

 

Table 1.1. Half-time re warm-up studies, a summary of the relevant literature.

 

Author(s)	Overview	Procedure	results
Lovell et al, 2013	Review of Muggleton study( see below)	Letter to International journal of sports med	Some research was not considered which may have led to faulty result
Muggleton et al, 2013	Comparison of high speed running throughout game	50 competitive matches examined using GPS	No difference in high speed running parameters
Edholm et al, 2015	Investigated the effects of half time re warm up on perform.	Time motion analysis used to compare results of groups	Half time passive protocol led to impaired sprint and jump performance
Weston et al , 2011	Examined a reduction in performance capacity at start of second half	Prozone data of 12 soccer referees using 152 premiership matches	Tempo of second half’s were proposed to be lower, leading to impaired perf.
Towlson et al, 2013	Examined warm-up strategies of pro soccer players	Internet questionnaire handed out to premiership and championship teams	Lack of time and coach unwillingness were major factors in lack of half time warm up
Lovell et al,  2013	Effects of different half time strategies on second half soccer specific speed	Used simulated soccer matches	Performance capacity decreased at start of second half compared with end of first across all groups
Lovell et al,  2013	Re-examined work rate of soccer players immediately after half time break	Time motion analysis 15 min passive half time rest	Players work rates lower after passive h/t recovery

 

 

CHAPTER 2  – LITERARY REVIEW

 

INTRODUCTION

GAA

The establishment of the Gaelic Athletic Association (GAA) in 1884 was the defining moment in the history of Ireland’s native games. Today the GAA regulates four distinctive games. The most popular of which are Gaelic football and hurling; the others are camogie and handball which although popular are played to a slightly lesser degree. Indeed Gaelic football (GF) is the one of the most popular sports in Ireland indeed research in 2011 showed there were 12,950 GAA teams spread throughout the country. In recent years the game has gone global. London and New York both have teams which compete with the Irish counties for the national title which is played throughout the summer months and gathers a spectator crowd of 80,000 every September for the competition final. There are reputed to be more than 2,500 Gaelic football clubs spread throughout Europe, the Middle East and Australasia played by players of all beliefs and backgrounds which is quite some fete for a game which was established with such  humble beginnings and with the aim to preserving Irish culture and heritage for future generations.

In general the game can best be described as a hybrid of soccer, rugby and basketball, although it predates all of these games. The game is played between two teams of 15 players on a rectangular grass surface approximately 137m long and 82m wide. Each team has 1 goalkeeper, 6 defenders split into 2 lines of 3, 2 midfielders and 6 attackers split into 2 groups of 3 also. The ball used is similar in size to that used in soccer. It is 69 – 74 cm in diameter and weighs approximately 460 g. Goalposts are placed 6.5 metres apart in the centre of each end line. A crossbar is attached to each post at a distance of 2.5 metres from the ground. A point is awarded when the ball is played by the hand or foot over the crossbar and between the goalposts. Three points are awarded when the ball crosses the goal-line between the two posts and underneath the crossbar after being played with a foot or hand strike ( Orejan 2006). Game play is quite fast and involves length of the field build up play and possession similar to that used in soccer and Austrailian rules. The ball can be transferred quickly between players with an unlimited amount of foot or hand passes. A player can take four steps while in possession of the ball. After four steps the ball must be either bounced or dropped onto the foot and kicked back into hand (solo tap). The ball cannot be bounced twice in succession.

In a continued effort to improve the game as a spectacle the rules are regularly tweaked, this year a mark has been introduced in an effort to speed the game up. A mark occurs When a player catches the ball cleanly from a Kick-Out without it touching the ground, on or past the 45m line nearest the Kick-Out point, he shall be awarded a ‘Mark’ by the Referee. The player awarded a ‘Mark’ shall have the options of (a) Taking a free kick or (b) Playing on immediately. It is this type of willingness to learn and evolve which has opened the door for strength and conditioning and sports science expertise to improve the physical approach to game play.

In recent years and as the Irish diaspora continually expands the game has gone global. London and New York both have teams which compete with the Irish counties for the national title which is played throughout the summer months and gathers a spectator crowd of 80,000 every September for the competition final. There are reputed to be more than 2,500 Gaelic football clubs spread throughout Europe, the Middle East and Australasia played by players of all beliefs and backgrounds

2.1 MOVEMENT PATTERNS – PHYSIOLOGICAL REQUIREMENTS

Optimal performance in Gaelic football requires that players develop the appropriate fitness attributes that allow them to cope with the physical demands of the game while maintaining technique and skill levels (Stephens 2004). During the game players are required to undertake irregular short duration intermittent bouts of high (short sprints and or change of direction), medium intensity/ distance exercises (jockeying in defence etc.) interspersed with short-duration recovery periods which are predominantly aerobic in nature (Stephens 2004). In addition, they must possess good strength and flexibility which in turn will allow them to obtain and maintain possession of the ball, optimally execute skills and tackle opponents.

Other studies of that time further highlighted the movement demands of game play and similarly to previous studies characterised the game as one  irregular changes of pace and anaerobic efforts interspersed with periods of light to moderate aerobic activity (Reilly et al 2003) . Club level players cover approximately 7.0 km during a game (Reilly et al 2002), the majority of which is spent jogging (24%) and walking (48%) (Reilly et al 93).

A more recent study carried out by Newell (2011) showed similar findings to the previous work Stephens and O Reilly, Newell discovered that Gaelic football required the players to run, accelerate and decelerate in a multi-planar direction; jump and land (requiring triple extension and flexion of lower limbs); pushing, pulling and twisting in various planes of movement whilst remaining balanced and involves a predominance of unilateral movements (Newell 2011).

More recent data using Global Positioning System (GPS) has shown how much the game has evolved over more recent years. One such study gathered data over four competitive games and has enhanced our knowledge on the effects of tactical changes during the game (Collins, Solan, & Doran, 2013). Significant differences were noted in relation to previous studies. Half-backs/forwards covered a greater distance (absolute and HI – high intensity) compared with players in other less demanding positions, generally those where players are positioned closer to the goal. Differences were also viewed in the HI distance covered in the first and second halves (876 ± 298 vs 819 ± 246m, p = .001) and between the first and fourth quarters (479 ± 178 vs 379 ± 107m, p = .028) further highlighting the need to establish whether through intervention can we maintain   , The maximum speed attained was 30 ± 1.4 kph and the average speed was 7 ± 1 kph These activity profiles suggest that football has a high anaerobic component

The majority of the game is played via the aerobic system and it must be trained to a high level to deal with imposed game demands. However many of the more important events during the course of a game involve single or repeated bouts of activity involving high running speeds and muscle work. The duration of these high intensity activities is wildly unpredictable, due to the fact that they are necessitated by the intermittent nature of the game itself and can vary greatly from player to player, position to position and from one game to another. Primarily, they rely on the phosphagen system and anaerobic glycolysis and the relative contribution of each system is dependent, in large part, on the intensity and duration of the high intensity activity and the recovery intervals (Cregg 2013).

Movement patterns

Mostly linear, with acute lateral movements and vertical   jumps. Some backwards running. Sagittal, transverse and frontal planes compromised (Newell 2011)

Major Muscle Groups

Generally; Pectorals, deltoids, biceps brachii, Triceps   Brachii, iliopsoas Abdominal, oblique’s, latissimus dorsi, erector spinae,   glutes, hamstrings, quadriceps, gastrocnemius and tibialis anterior and   posterior (Newell 2011)

Joint Angles

≥45 – ≤180 degrees for most major joints. (Perhaps <45   for lumbosacral joint when bending to pick up ball) (Newell 2011)

Fibre Recruitment

Ranges from type IIa, b– type I. Types II dominant in   periods of play. (Newell 2011)

Contraction type

Isotonic, isometric   contraction of major muscles groups, eccentric and concentric loading. (Newell 2011)

 

2.2 WARM –UP

Despite limited scientific evidence supporting their effectiveness, warm-up routines prior to exercise are a well-accepted practice. Although considered essential for optimum performance by many coaches and athletes, there is surprisingly little scientific evidence supporting the use of warm-ups. Evaluating the findings of the many studies that have investigated the physiological responses to warm up is somewhat troublesome. Many of the earlier studies were not well controlled, contained too few study participants and often omitted statistical analyses. Moreover, warm-up procedures have differed in their duration, intensity, recovery periods, mode of exercise and whether the warm –up was continuous or intermittent.

The majority of the effects of warm up have been attributed to temperature-related mechanisms (e.g. decreased stiffness, increased nerve-conduction rate, altered force-velocity relationship, increased anaerobic energy provision and increased thermoregulatory strain), although non-temperature-related mechanisms have also been proposed (e.g. effects of academia, elevation of baseline oxygen consumption (˙VO2) and increased post activation potentiation). It has also been hypothesised that warm up may have a number of psychological effects (e.g. increased preparedness) (Bishop 2003).

Warm-up techniques can be broadly classified into two major categories: passive warm up or active warm up.

 

 

 

 

 

 

 

 

2.2.1 PASSIVE

 

Passive warm up involves raising muscle or core temperature by some external means. Passive heat maintenance involves the use of specific methods (e.g., heated clothing, outdoor survival jackets, and heating pads) which seek to protect against heat loss. Such strategies are easily applied to the desired muscle groups to maintain Tm, and thus the temperature-mediated pathways which aid performance (KIlduff at al 2013). For example, when professional Rugby Union players applied a Blizzard TM survival garment during a post warm-up recovery period, subsequent repeated sprint performance and lower body peak power outputs were greater than elicited in a control trial (KIlduff et al 2013). Additionally, the decline in lower body peak power output observed during the post warm-up recovery period was related (r=0.71) to the decline in body temperature.

While active warm up utilises various types of exercises and movement approaches to elicit muscle temperature raising, Passive heating allows the athlete to obtain a similar increase in muscle or core temperature as achieved by active warm up without depleting energy substrates. Passive warm up, although not practical for most athletes, also allows one to test the hypothesis that Warm up is a widely accepted practice preceding nearly every athletic event (Bishop 2003).

 

 

 

 

 

 

 

 

 

2.2.2 ACTIVE

For ease of testing in this study we will use active exercise based warm ups. This involves using movement based activities i.e running, jogging, plyometric etc. to raise body temperature in preparation for performance.

While the physiological benefits associated with warm-up before aerobic performance may also add value to the anaerobic performance, results from research scoring warm-up and its effect on more intense exercise performance have been inconclusive. Studies have shown that there may be a dose response to the intensity and duration of warm up which seems to be the key take home point. Too little and no response is effected whereas too work coupled with too little break can have a negative effect on recovery and performance. Studies have shown a lack of improvement in anaerobic performance after warm-up at 80% VO2 max may be due to metabolite build up occurring during the warm-up, whereas an Increased anaerobic performance has been shown after warm-up at 60 and 70% VO2 max for around 15 mins with appropriate recovery, this may be the result of a maintained reactive hyperaemia which increases the aerobic contribution to energy supply during the initial’ stages of exercise (Stewart et al 1998, Bishop et al 2003).

Mohr et al.  identified that moderate intensity running commencing after seven minutes of a half-time recovery period attenuated a 1.5°C reduction in Tm and a 2.4% decrement in mean sprint performance observed when passive control practices were employed. Additionally, the decrease in Tm at half-time was correlated to the reduction in sprint performance observed during the half-time break (r=0.60).

More recently, Edholm et al reported similar magnitudes of sprint performance maintenance and attenuated losses in jump performance following a low-intensity half-time rewarm-up. Similarly, beneficial effects of active heat maintenance strategies have also been observed when intermittent agility exercise, whole body vibration, small sided games and lower body resistance exercises have been performed during half-time ( Zois et al 2013 , Lovell et al 2013) . Active rewarm-ups may also be of benefit to skilled, as well as physical performances, executed in the second half. For example, seven minutes of low/moderate intensity activity and light calisthenics performed towards the end of half-time improved performance during an actual match as less defensive high-intensity running, and more ball possession, was observed in the second half. In support of the findings of Edholm et al 2014, skilled performance has also been reported to be maintained when technically focused half-time activities are performed (Zois et al 2013).

Issues do remain from these studies as some of the works can be difficult to relate to real match scenarios where spatial restrictions and environmental constraints may hinder any intervention.

 

 

2.3 Post-activation potentiation (PAP)

We have seen the many benefits of warm up ( increased heart rate , injury prevention etc.) but one of the most sought after effects of the warm up is a priming of the central nervous system in preparation for the high muscular demand in game activities i.e sprinting , jumping and change of direction. The contractive history of a given muscle group can influence the ability of the same muscle group to produce force (Kilduff et al 2008). In other words if the neuro muscular system is fired appropriately prior to performance then it may allow the body to produce more force. This phenomenon is called post activation potentiation ( PAP) and  is proposed to excite the neuromuscular system and aid in rate of force development which can make the athlete more responsive to stimulus, react quicker thus performing some of the important aspects of the game at a faster rate that his direct opponent.

Although a large body of research supports the ideal that muscular performance can be positively enhanced by a preload stimulus (Gouvea et al 2013), not all studies have demonstrated the same physical effects. A number of factors have been found to influence the PAP response (e.g., the strength of the participant, volume and type of the preload stimulus, and the duration of recovery between the preload stimulus and subsequent activity- the dose response relationship) (Tillin et al 2013). However, when considering the potential application of PAP during the half-time period of team sports, the type of activities performed and the timing of the preload stimulus are likely to be of primary interest. It is a familiar sight to see teams huddle before games and perform PAP drills. Often it is the form of plyometric jumps followed by a turn and sprint, 5 meter accelerations and maybe some react to stimulus (whistle starts etc.). This study isn’t primarily concerned with these  shorter  PAP drills but instead will focus on performing a holistic re warm up with different intensities and patterns  before the game recommences, the  plyometric elements ( PAP drills) will be placed close to performance in line with dosage recommendations but it is part of a bigger picture.

2.3.1 PAP TIMING

There is a dose response principle which governs the effectiveness of the PAP response. The timing between the preload stimulus i.e weighted jump, bound etc.  and subsequent activity (match , sprint ) is key. Too much recovery will elicit a return to baseline levels and too little recovery will leave too much fatigue in the system for the body to overcome and consequently the PAP effect may be lost (Wilson et al 2013).Therefore, optimized recovery between the preload stimulus and the subsequent exercise favours an acute enhancement of subsequent performance as the decay in the rate of potentiation is less than the rate of decay of fatigue (Hamada et al 2003). Additionally, the time demands associated with established half-time practices are likely to influence the decision on whether to even recommend performing any type of muscle potentiation. Recovery periods ranging from zero to 24 minutes have previously separated the conditioning exercise and the subsequent explosive activity. Notably, in a study incorporating professional rugby players and repeated assessments (i.e., baseline, ~15 s and every four minutes) of explosive activity for 24 minutes after the preload stimulus (three sets of three repetitions at 87% 1RM squat), Kilduff et al.  identified that power output, peak rate of force development and countermovement jump height were significantly elevated above baseline values at about eight minutes of recovery for the majority (i.e., 70%) of participants; a finding which has since been confirmed by a recent meta-analysis (Gouvea et al 2013). The PAP effect has been shown to have a short lived response meaning that the benefit to performance may be limited to the initial stages of a player’s involvement in subsequent competition. From studies where a heavy resistance exercise has been used to induce PAP, explosive lower body power production is consistently compromised immediately after the preload stimulus (Gouvea et al 2013). From a practical point of view if a PAP response is a desired outcome from the coaches half time re warm –up routine then the timing of the stimulus needs to be made in relation to the commencement of the second half ( 7 – 8 mins Wilson et al 2013). Performing the jumps prematurely will elicit no response to the neuromuscular system and hence no benefit (Gouvea et al 2013).

2.3.2 Type of preload

The majority of studies examining the PAP phenomenon have employed heavy (i.e., 75-95% 1RM) resistance exercise as the preload stimulus (Gouvea et al 2013) and have primarily just looked at the PAP stimulus exercises as a stand-alone piece. This may be a beneficial theoretical model but practically it may not be realistic under real match conditions. Dressing rooms may be too small, many clubs will not have gyms in close proximity to change room and the transport of weights in the numbers required is a further logistical constraint.  Therefore, less equipment heavy methods will need to be used to program any PAP exercises we may wish to use.

Ballistic activities such as weighted jumps are associated with the preferential recruitment of type 2 motor units (Desmedt et al 1977), and therefore may be utilized as a PAP stimulus .Many other types of  plyometric exercises have  also been found to potentiate sprint performance – long jumps , Pogo hops and hurdle jumps . Improvements in jumping performance have been observed in the two minute period following a preload stimulus that included jumps against a resistance of 2% body mass (via a weighted vest) that were incorporated into a dynamic warm-up (Faigenbaum et al 2006). Similarly, although effects dissipated after six minutes, (Chen et al. 2013) have reported improvements in countermovement jump height following multiple sets of depth jumps. Turner et al have recently reported that ~75 s of alternate-leg bounding performed with (+10% body mass) and without (body mass only) a weighted vest, potentiated subsequent sprint performance when compared to a control trial. Notably, a greater enhancement of sprint performance was observed in the body mass plus 10% trial when compared to the body mass only trial and this increase was related to the baseline speed of the participants.

 

 

 

 

 

 

 

 

2.4 ACTIVATE GAA WARM-UP

We now know the benefits of an active warm up over that of a passive one but many different types of active warm up have been used in the past.

In the past an aerobic warm up followed by a period of static stretching or vice versa was certainly a go to template. Whilst this method did have some benefits i.e increased muscle temperature etc. the period of static stretching was proposed to be detrimental to performance as it lasted too long and allowed the body to cool down (McMillan 2008). A dynamic warm up was then suggested as an alternative as studies revealed that for tasks requiring power and agility, that a dynamic warm up (DWU) might offer performance benefits not found with static stretching or no warmup (Mc Millan et al 2008). Although the DWU often varies in protocol, it typically includes dynamic stretching, agility, plyometric and specific game motor pattern movement’s i.e cutting, stepping decelerating etc. In essence, a combination of these techniques can prepare the body for performance by improving core and muscle temperature, enhancing nervous system function (i.e., post activation potentiation) and using similar movements that occur during subsequent exercise. Indeed dynamic stretching has been shown to improve several performance factors such as shuttle run time, medicine ball throw distance, 5-step jump distance, electromyography activity, lower extremity power and vertical jump (Agular et al 2012).

I will be using a dynamic warm up for my testing protocols. It will be pre planned and the same

Routine will be followed throughout the study with the same exercise order and timings throughout.

Rather than use my own constructed warm up I decided to use one which was well researched and

Shown to have a multifaceted benefit to performance. For obvious reasons I chose the activate GAA

Warm –up. It has been  developed by Sports Institute Northern Ireland (SINI), Ulster GAA coaches and a group of Sports Medicine Professionals (including County team Physiotherapists, Physicians

And Orthopaedic Knee Consultants). The creators claim it is based on solid medical research (as it is based from the well-researched FIFA 11+ model) and, if performed regularly with proper technique, can reduce non-contact leg injuries by up to 50%. The warm-up has been adapted from FIFA’s successful 11+ programme to meet the specific needs of GAA players and is appropriate for use with GAA Football, Hurling and Camogie squads.  This Warm-up facilitates the “switching on” and activation of the correct muscles and motor patterns in preparation for intense activity (stojanovic et al 2012).

 

 

Activate is comprised of three phases:

Phase 1: Running, Cutting and Landing Mechanics – 5 x 2
Five drills are completed in which the first part is performed moving out through the centre of the channel, and the second part returning down the sides of the channel. Each drill is performed twice.

Phase 2: Strength, Plyometric and Balance – 10 x 10
there are two circuits: 1 and 2 which should be rotated every month. Squads carry out Circuit 1 for one month before progressing to Circuit 2 in which several of the exercises are more dynamic or require greater strength.

Upon completion of Circuit 2 for one month, squads should then alternate monthly between circuits 1 and 2.This is in order to return the players’ focus to the control and perfection of technique required in the Circuit 1 exercises.

Phase 3: Agility and Power – 5 x 2
five drills are completed: three moving out through the central channel and returning down the sides, and two performed on the base line.

All three phases of Activate should be implemented before training with only phases 1 and 3 necessary before games. Once completed, the coach can then deliver any preferred drills or small sided games at full pace. Whilst Activate contains a dynamic flexibility component, the coach can add any other specific stretching/flexibility exercises to the routine.

Remember: Allowing players to carry out the exercises without feedback and accepting poor technique will not reduce injuries. Time spent early in the season perfecting technique will produce greater athleticism and reduced injury frequency later in the year.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.5 Power

Power is defined as the work performed per unit time and is the product of force multiplied by distance (Baechle et al 2008)). Explosive power is generated by the legs and hips and through the upper extremities and trunk musculature (Armstrong 92).  Many of the important activities in Gaelic football such as physical collisions, competing for possession, breaking a tackle, jumping to catch a kick-out, and accelerating from a stationary position require muscular power (Cullen 2013).

The performance of sport as for all physical exercise is the result of a coordinated activation of the appropriate skeletal muscles (Komi 92). These muscles, acting through the lever systems of the body skeleton, provide the forces and the power that can be translated into skilled movement. The human body is capable of power production over a wide range of movement intensities from low-intensity aerobic exercise, to exercises requiring peak oxygen uptake for the muscles involved, high-intensity anaerobic exercise emphasizing anaerobic glycolysis as the main energy source, and the highest power productions which rely solely on the high-energy phosphates as the energy source (sprinting etc.). Particularly for the peak contractions there is a limited time for the body to produce force, for instance once the athlete leaves the ground to jump for a kick out then he/she can no longer produce much more force for that action. Thus these maximum contractions have a minimal window of use to an athlete. It has been documented that each athlete is reliant on three mechanical factors in order to elicit the best response from his/her efforts to create a powerful action.

1. To develop the largest amount of force in the shortest time possible (rate of force development) (Hori 2007)

2. The ability of the muscles to produce a high force at the end of the eccentric phase and the beginning of the eccentric phase (Hori 2007)

3. The ability of the muscle to continue producing force output as the velocity of its shortening increases (Hori 2007)

The physical quality of field sports have changed dramatically over the last number of years. Today participants are subjected to numerous actions that require overall strength and power production, speed, agility, balance, stability, flexibility, and the adequate level of endurance, thus making the conditioning of players a complex process.

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2.6 COUNTER MOVEMENT JUMP (CMJ)

We have seen how explosive muscle power is the main determinant of performance in many individual and team sports (18) and can be successfully developed with the training consisting of movements with high power output and maximum rate of tension development (22, 27) e.g. Squat, squat jumps, Olympic lifts etc. For the purpose of training monitoring it has become evident that strength and conditioning professionals use reliable and valid tests when assessing explosive power of athletes. The results of  a study by Markovic et in 2004  have the following implications for the assessment of explosive power of the lower limbs: (a) all popular horizontal and vertical jumping tests have acceptable between- and within-subject reliability, so they can be used for the estimation of jumping capabilities in physically active men. (b) Among all popular jumping tests, SJ and particularly CMJ measured with a contact mat connected to a digital timer are the most reliable and valid tests for the estimation of explosive power of the lower limbs. Hence, strength and conditioning professionals are advised to use SJ and CMJ for the estimation of explosive leg power.

For the purposes of my study I will use the CMJ as a performance measure. We have seen how valid a test the CMJ has been found to be in relation to tracking power output as used in studies for monitoring the muscular readiness of athletes across a broad spectrum of sports. Importantly in relation to this study researchers have also discovered the CMJ to be both a reliable and objective marker of both fatigue and super compensation. Some issues and disparities were found but the attributing factors were found to be many and varied i.e population type, duration, activity intensity, kinematic and kinetic variables such as jump height, peak power, flight time etc.

 

 

 

 

2.6.1 CMJ IN GAELIC FOOTBALL

Vertical jump height is also been shown to be related to running velocity over distance between 5 and 30 m (Cronin et al 2005). The ability to accelerate is a hugely beneficial locomotive skill in Gaelic football. Important game activities such as winning possession of the ball, evading opponents, and breaking tackles involve single or repeated bouts of activity involving high running velocities and muscular power. The duration of these high-intensity activities are largely unpredictable because of the fact that they are imposed by the pattern of play and can vary greatly from player to player and from one game to another (Cullen et al 2013) .Again due to lack of study data there is not too much CMJ information available in relation to Gaelic football . Vertical jump heights has been found to range from 50 – 65 cm in Gaelic football players among elite collegiate level Gaelic football players, midfielders produce 35 greater power during the vertical jump as well as greater vertical displacement than all other positions (McIntyre & Hall 05). Although the relatively small number of subjects (n=28) in this study may not be representative of collegiate players nationwide, this particular finding is not surprising considering that midfield players are required to compete for aerial possession more frequently than players in any of the other positions (Cullen et al 2013). Performance in the CMJ test is similar in collegiate level defenders and forwards and elite county players (Watson 05, McIntyre &Hall 05).

Table 2.1 Selected data that evaluated CMJ performance in Gaelic football

Level   Position  n  CMJ (cm)

McIntyre & Hall (05)     Collegiate  Defender  12  54.0 ± 7.2

McIntyre & Hall (05)     Collegiate  Forward  12  56.0 ± 6.0

McIntyre & Hall (05)     Collegiate  Midfield  4  65.0 ± 4.0

Watson (05)             County –    32  50.3 ± 5.8

B k & ’D (05)              County –                  25  62.2 ± 5.1

Kirgan & Reilly (93)      Club –     15  48.6 ± 4.7

Values are mean ± SD.

These scores measure quite favourably with other multi sprint field sports ( Aussie rules 60.7 + 5.8 – (Veale et al 08) , Rugby league 51.6+ 7.7 ( Gabbett et al 09)  and indeed highlight the natural athletic ability of GAA athletes as formal and indeed specific strength and conditioning programs and exercise rationale have only come mainstream in the last 5 years or so.

 

 

 

 

 

2.7 summary

Gaelic football is part of the bedrock of Irish sporting life. Its amateur roots are in stark contrast to its professional approach and the amount of time and effort spent in using sports science to perfect the physical preparation of the game. Unfortunately although the game has seen pioneering research it has not been widely studied. Most of the research thus far to the author’s knowledge looks to investigate the physiological demands, movement patterns of the sport compared to other field sports with little research looking at possible interventions which could be used to enhance the physical performance of the players. This highlights a gap in GAA research and this study aims to shed some light into the using the half time period as a possible potentiation platform in preparation for the second period.

Warm ups in general have been shown to effectively prepare athletes for performance no matter what movements are required for the sport and no matter what intensities. Each sport will require its own research as to what warm –up models specially suit each athlete. But as a general rule it is the combination of exercises chosen and their subsequent timing dosage which will have the largest effect on the effectiveness of each warm up. For the purposes of this study we will be using a dynamic warm up similar to the FIFA 11+ model to prepare the participants to perform. It has been carefully chosen as it is well researched and provides the athlete with all the bodies needs prior to a Gaelic football match – respiratory rate increase, elevated heart rate, increased muscle temperature, joint elasticity, dynamic control, core stability, game specific running skills and neural potentiation.

 

 

CHAPTER 3

METHODOLOGY

Much of the current literature shows a decrease in high intensity running and player work-rate after a passive half-time recovery.  The muggleton paper of 2013 used GPS for the first time to gather info and compare different parts of the game from an intensity point of view. This study did not find any difference between the amount of high-speed running and sprinting completed by semi-professional soccer players when the first 15 minutes of the first and second half of competitive matches were compared, although the total distance completed by players was less and their mean speed lower in the first 15 minutes of the second half of matches. The maintenance of high-speed running and sprinting, as total distance and mean speed declined, may be a function of the pacing strategies adopted by players in competitive matches (Muggleton et al 2013). Lovell et al reviewed this paper in the same year and claimed that the Muggleton paper had not considered some key research (Bradley at al 2009, Lovell et al 2012, Weston et al 2011 & Weston et al 2012) which may have screwed their research results somewhat. These studies (Bradley at al 2009, Lovell et al 2012, Weston et al 2011 & Weston et al 2012) show a reduced high intensity work-rate after half time passive recovery and inversely imply that a re-warmup may be a beneficial method of allowing a more intensive work-rate at the beginning of the second half. Indeed Lovell pointed us to relevant studies which showed that a half time rewarm up was not detrimental to performance (zois et al 2013, Lovell et al 2013).

 

 

3.1 PARTICIPANTS

30 Male (we will include goalkeepers goal keepers) senior club Gaelic football players will be selected for trailing process. All the participants will be screened for both injury and general health prior to testing and they will also be asked to fill out a perception of mood state (POMS). Following the first half the players will be randomly assigned to one of our three study groups (1.) Control group (2) Dynamic warm up (3) Aerobic warm up

3.2 STUDY DESIGN

PRE PARTICIPATION

All participants will be required to attend a pre participation workshop in the week before testing begins.  Also at this stage the players will be physically screened to assess fitness status and information will be gathered in relation to injury status and training age and they will be asked to fill informed consent.

 

A schematic of the study design is presented below in figure 1.1. Each player will complete an 8 week preseason program which will consist of mobility, strength and energy systems development.  For the purpose of contrast I will use 3 distinct groups throughout my study period (1) control group – CON (2) Dynamic warmup- DYN (3) Aerobic . The players will be allocated to their groups after the first half has ended. They will perform the same pre game warm up routine as they have done before previous games thus avoiding any result complications due to using an unfamiliar study protocol. After the warm up they will be all asked to do 3 counter movement jumps (CMJ) to assess their power output before performance. They will then play a 30 minute trial game under full match conditions i.e club standard referee, umpires, full size pitch etc. The length of the half-time interval (15 minutes) will be monitored using a stopwatch and is understood to be  the time immediately following the referee’s whistle to end the first half of play up to the referee’s whistle to start the second half. The length of half-time will be controlled by the researcher and will be of the same time period as a normal match condition. Players will return to the changing rooms at half-time and recover passively. Once they have returned to the change rooms they will be asked once again to perform 3 CMJ’S to assess the effect of game fatigue on power output from the first half. Following this they will be randomly assigned to their intervention groups by the researcher.  During the initial stages of the break each player will rest for 8 minutes where they will rehydrated, refuel and receive performance instruction from the coaching team. After which the (CON) group will continue to rest the (AER) group will re-warm on pitch using a prescribed constant movement based routine and the final group (DYN) will  re-warm up on the pitch dynamically essentially a shorter version of Activate GAA warm up. Before the second half commences the players will be asked for a final time to perform three CMJ’S this will give us an idea of our power output for the second half. After each game players will be asked to fill out a rate of perceived exertion (RPE) score so we can gather some info as to how the players felt they applied themselves physically in game.

 

 

 

 

 

 

 

 

 

 

 

 

 

3.3 SCHEMATIC

NOTE – EACH GAME WILL FOLLOW THE SAME PATTERN AS THE PREVIOUS GAMES.

All data will be collected by myself and entered electronically into a password protected excel document which only I have access to. All outcome data will be de-identified using a numbering system instead of participant name.

3.4 EQUIPMENT

I will be using the FSL Jump mat for the testing series. The FSL Jump Mat consists of a hand held electronic timer connected to a contact mat (tape switch Signal Mat, model CVP 1723, tapes witch, Farmingdale, NY) measuring 584 x 432 x 2 mm. The system resolution is 1000 Hz with a threshold for operation of 2.3 kg. Jump height is calculated using the formula; h=g·t2/8 (where h is the jump height in metres; g is gravitation acceleration [9.81 m·s-2]; t is the flight time in sec) (Bosco et al 83) Contact mat devices are used routinely in research projects and within many sporting institutions (Enoksen, Tonnessen, & Shalfawi, 2009; Hennessy & Kielty, 2001). One of the most commonly used contact mat devices to assess vertical jump performance is the FSL Jump Mat (Allison, Bailey, & Folland, 2008; Rodacki, Fowler, & Bennett, 2001). Questions about the validity of the measurements recorded from this device have been demonstrated in the past with some authors suggesting the hardware and software used in many contact mat devices may introduce unacceptable margins of error (Garcia-Lopez et al., 2005; Kibele, 1998). However a test carried out by DR. Rodney Kennedy at the University of Ulster Jordan town in 2011 to determine the concurrent validity of the FSL Jump Mat using a force plate as a criterion reference proved that the FSL Jump Mat can be recommended to monitor training adaptations in vertical jumping capacity based on flight and contact time measurements (Kennedy 2011). The results from this study reveal that the FSL Jump Mat is a relatively accurate testing device. However, the significant difference between the FSL Jump Mat and the force plate measurement highlights the importance of using the same equipment when comparison is intended or required. The lightweight portability of the device was also highlighted as advantageous as it possess high applicability within field based sports testing

CMJ PROTOCOL

The hands-on-waist countermovement jump (CMJ) is one variation of the countermovement jump protocols. It reduces the lower extremity stretch shortening cycle (SSC) capability contributed by arm swing, thereby being more reflective of leg power performance (Hara, Shibayama, Takeshita, Hay, & Fukashiro, 2008). Equipment using electronic mat systems have been developed to detail jump height indices from CMJ performance (Bosco, Luthanen, & Komi, 1983). A good quality contact mat system will estimate lower body output after flight time is initiated from feet off and deactivated from landing. In CMJ, the athletes begin in a tall upright position with their hands on the waist with the eyes facing front. Upon hearing the ready signal from the tester, the athlete lowers to a self- selected squat depth and without pause at the bottom will explosively jump as high as possible. It is imperative that the athlete maintains the position of the arms on the waist all throughout the jump in order for the score to be valid and reproducible. A trial is considered valid if full hip, knee and plantar flexion are observed at the peak of the jump i.e no tuck jumping, legs straight at apex of jump. The athletes should be able to maintain this position until landing.  During landing, the toes should land softly on the contact mats in the same position as take-off while absorbing the jump right by hip and knee flexion right after the foot contact. Additional trials were requested by the tester if it was felt that a participant executed a faulty jump pattern or if a technical error was observed. The test must be consistently administered throughout the team and a period of practice is suggested so players are familiarised with what is required to achieve an accurate score.

3.6 STATISTICAL INFO

I used the statistical software package SPSS (SPSS Inc. Chicago IL, USA) and Microsoft Office Excel 2016 (Microsoft, USA) to mathematically interpret study findings. A 1–way mixed analysis of variance (MIXED ANOVA) with repeated measures on both factors (time and groups) will be used. Tukey post hoc analyses will be employed to account for multiple comparisons problems and to maintain if significant differences are found between groups. Statistical significance will be accepted at P- value < 0.05 level.

 

 

 

 

 

 

Figure 3.5 – profile plot

 

 

 

 

 

 

 

 

DISCUSSION

The purpose of this study was to determine whether there was a return to baseline power measures prior to the start of the second half following three different interventions. We also were interested to see whether there was a distinct advantage in using one warm up method over the other as they were of different intensities.

WE have seen how the GAA has evolved scientifically over the last number of years and the current players and game of today are thoroughly professional in approach. The physical appearance of players through all levels, club included, has altered dramatically in recent times. All efforts are aimed at getting the competitive advantage over the opposition, this encompasses all aspects of performance and any method or intervention that could lead to increased physical readiness would be much sought after by coaches and players alike. In my mind there seemed to be some research gaps, particularly in the more appropriate use of the half time period. Many studies (Muggleton et al 2003 etc.) have previously shown a positive effect in re warming up and half time and my hope was that we could see the same advantage for our Gaelic football players.

The results of this study didn’t back up the author’s assumptions as to what the outcome of the interventions might be. It was thought that of our intervention groups that the active ones would have a more beneficial effect on second half readiness and consequently that each of these would be more advantageous to second half performance than rest. Finally it was considered that the higher intensity warm up would elicit a greater PAP response due to heightened neural stimulus elicited from more explosive exercises (jumping, bounding, sprinting etc.). This increased readiness would be of greater benefit to the athletes than the slower tempo work carried out during the aerobic intervention.

On studying the results much of what was thought in relation to the studies outcomes and indeed what has been uncovered in previous studies was found on this occasion to be inconclusive. Neither of our active study groups displayed any significant increase in performance measures i.e jump height following intervention. Furthermore there was found to be no clear advantage over using one warmup type AER over the other more intensive DYN version. The one perhaps encouraging aspect of the results was that although statistically insignificant there does seem to be a greater drop off in jump performance from the control group. It is a conclusion that is to be taken cautiously due to the lack of statistical power but it is indeed an area for further research.

Much of the lack of study findings could be down to several factors many of which are logistical. Firstly the timing of the half-time period was an area of concern. If we are to follow real half time protocols and to make results as match real as possible then 15 minutes is the max time allowed to carry out any intervention. This leaves very little time scope. Many of the players who finished their jumps last went straight to their controls without the recommended rest. On the other hand those who jumped first may have had too much break. There was other issues with players both new to the CMJ (adding both time and inconsistent scores) and indeed others not applying max effort per jump. I think a more longitudinal study period would give us a clearer indication as to whether our proposed methods of study are more valid.

Although not the aim of this present study it was interesting to see the increase in jump height immediately after halftime in all players. Again this would seem to go against logical reasoning and against the perception that fatigue would have a large effect on jump height. There could be many reasons for this such as player level, game intensity etc. but an interesting finding nonetheless. Although outside the scope of this study and accordingly not investigated here, it is very interesting to note that several researchers have reported an increased risk of muscle injury (i.e., non-contact injuries) during the initial stage of the second half of match play in soccer (Hawkins & Fuller, 1996; Rahnama et al., 2002). As it is well known that a drop in muscle temperatures such as those typically reported after passive half-time period in soccer players (1.5–2.0 °C) (Mohr et al., 2004; Lovell et al., 2013) is associated with a higher likelihood of muscle injuries (Safran et al., 1989), and that a re-warm up regime such as the Activate GAA one used in this study guards against such decrements (Mohr et al., 2004; Lovell et al., 2013) it might be rightly reasoned  that a half-time re-warm up also is an effective method to prevent muscle injuries during the initial phase of the second half. Thus, the chance of half-time re-warm up regimes as an injury prevention protocol in Gaelic football warrants further research.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CONCLUSION

 

It appears that neither of study groups had any real effect on jump performance pre second half. There were a number of reasons offered up as to why this may be so and to offer some insight into future research in the same area. Logistical issues and planning were considered to be of the utmost importance if future studies are to uncover as reliable a results sequence as possible.

To my knowledge an understanding of the effects a half time break has on the physiology of Gaelic footballers has never before been investigated.  This lack of comparable data makes a pilot study such as this difficult to standardise. For instance we have no real data to compare the results of our study to and indeed there was no previous findings and indeed recommendations for us to base our study design on making results accuracy a more difficult task. The use of interventions and indeed sports science is relatively new in the GAA particularly amongst club players, the use of such technologically advanced equipment such as a Jumpmatt may be met with some scepticism from participants who may not see the value in adding science to their performance. Similar to the Muggleton et al study of 2013 I would be worried that amateur players may have become accustomed to adopting a second half pacing strategy in order to reserve energy for the later stages of the game, this would have real negative effects on study findings.  I would have other minor concerns about the effects of fatigue on performance and in the player’s general adherence to a testing protocol. Many of these participants are multi-sport athletes which often requires them to train throughout the week and often to play 2 games over a weekend, combined with an amateurs lifestyle i.e diet , socialising etc. it would concern me in regards the studies continuity. On the other hand I believe this will be reality for any studies in Gaelic football and ultimately interpretation of fatigue may be outside the scope of the present study and indeed could be an area to study of its own i.e the effects of fatigue on high speed running performance of dual sport athletes.

My ultimate intention was to add to the present GAA sports science literature and try and make it as practical as possible in relation to club Gaelic football. In doing so I hope that others could learn from our discoveries and ultimately help marry the science and the practice, done over a number of games and with regulated and consistent supervision I believe we would get a very comprehensive picture of our hypothesis and one I suggest which would be of great benefit not only to understanding the needs of the game but to grasping what it takes to achieve a high level of performance at a sub elite level.

 

STUDY LIMITATIONS

For the benefit of future studies in this area I believe that a review of the testing procedures would be of most benefit in order to achieve more conclusive results. I think the use of multiple jump Matts would be of huge benefit in both data collection and time management. Using 1 matt made the timing very difficult to maintain. For instance if you were any of the last athletes to test you had a diminished chance to induce any PAP effect before the game as you basically started the game immediately after your jump. They also had an increased recovery period post half time as they had to wait for all the other athletes to jump before them ( this took up to 8 minutes to execute) which could positively affect your jump performance in that block.  Inversely you could potentially have less break on the other side of this jump as you may be in one of our active warm up groups who would be taking the pitch to re-warmup, which due to time constrictions was very close to the last athletes jump.

While much closer to the ‘real’ situation, in house matches can lack real intensity at times and hence can fail to induce the responses in fatigue and nervous system stimulation which can only accrue from actual competition (Muggleton et al 2013).

We uncovered through research that the mode of the conditioning exercise, intensity, recovery time, type of contraction as well as the players’ training status will determine the individuals response in either potentiating a subsequent exercise task or inducing fatigue (Brandenburg et al 2005, Tillin et al 2009). Under this scope, it is suggested that the most beneficial of warm up mechanisms i.e PAP are more efficient in well trained individuals rather than in recreational athletes, probably due to their capacity to recruit more motor units at a higher firing rate during the conditioning exercise (Chiu et al 2003). For this reason maybe coaches should determine each individual’s optimal exercise mode in order to optimize the positive effect of the re warmup activity in players’ performance response after the warmup (Abade et al 2017) . PLY and RCOD are efficient post activation activities that induce acute positive effects in both vertical jump and sprint capacities. Future investigations should be focused on the effects that different R-WU activities may have across the 60 minutes of a competitive match.