Grant M Duthie

Australian Catholic University Strathfield NSW · School of Behavioural and Health Sciences

Player movement is a fundamental component of evaluating performance in most team sports. Movement can be evaluated across multiple scales, referring to the function of anatomical structures through various planes of motion or an individual regulating their field position based on the movement of opposition players. Developments in commercially ava...

Background Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the...

Electronic performance & tracking systems (EPTS) are commonly used to track the location and velocity of athletes in many team sports. A range of associated applications using the derived data exist, such as assessment of athlete characteristics, informing training design, assisting match adjudication and providing fan insights for broadcast. Conse...

Three-dimensional motion capture systems such as Vicon have been used to validate commercial electronic performance and tracking systems. However, three-dimensional motion capture cannot be used for large capture areas such as a full football pitch due to the need for many fragile cameras to be placed around the capture volume and a lack of suitabl...

This study aimed to observe whether there were substantial differences in acceleration during team-sport locomotion between GNSS manufacturers. Speed and acceleration were obtained from 7 professional rugby league athletes via 2 GNSS manufacturers (GPSports EVO, 10 Hz and STATSports Apex, 10 Hz) worn together during the same training sessions (n =...

The impact of the six-again rule change on the movement of National Rugby League (NRL) athletes was examined. Player Global Navigation Satellite System (GNSS) data (10 Hz) was collected from 42 athletes whom competed in 56 matches across the 2019 to 2021 NRL seasons. Maximal mean speed(m·min-1) and acceleration (m·s-2) were established across a 10-...

Player movement metrics in football such as speed and distance are typically analysed as aggregates, sometimes outside of any specific tactical or match context. This research adds context to a player's movement over the course of a match by analysing movement profiles s and bringing together tools from the sport science and sports analytics litera...

Background Wearable tracking devices are commonly utilised to quantify the external acceleration load of team sport athletes during training and competition. The ability to accelerate is an important attribute for athletes in many team sports. However, there are many different acceleration metrics that exist in team sport research. This review aime...

This study presented a method of quantifying the manoeuvrability of two field-based team sport athletes and investigated its relationship with running velocity during competition. Across a season, 10 Hz Global navigation satellite system (GNSS) devices were worn during matches by 62 athletes (Australian Football League [AFL]; n = 36, 17 matches, Na...

This study aimed to quantify the validity and reliability of load–velocity (LV) relationship of hill sprinting using a range of different hill gradients and to describe the effect of hill gradient on sprint performance. Twenty-four collegiate-level athletes performed a series of maximal sprints on either flat terrain or hills of gradients 5.2, 8.8...

Objectives (1) Determine the inter-device and inter-manufacturer reliability; and (2) investigate the variation in reliability over time for common global navigation satellite systems. Design Repeated measures. Methods A total of twenty 10-Hz devices manufactured by StatSports (n = 10, Apex Pro; StatSports, Newry, Ireland) and Catapult Sports (n...

Background The use of Global Positioning Systems (GPS) has provided Sports Scientists with the ability to investigate locomotive behavior in sport. With Lacrosse being the fastest growing sport in the USA, there is no GPS analysis available, in current literature, for female lacrosse competition.AimsThis study aims to quantify the external outputs...

Background Technology has long been used to track player movements in team sports, with initial tracking via manual coding of video footage. Since then, wearable microtechnology in the form of global and local positioning systems has provided a less labour-intensive way of monitoring movements. As such, there has been a proliferation in research pe...

The aims were to investigate the externally measured weekly loads, and the distribution intensity relative to the 1-min maximal mean (MM) intensity of matches. Athletes ( n = 28) wore 10 Hz GNSS devices during training and matches. For the descriptive analysis, a range of movement variables were collected, including total distance, high-speed dista...

Goal-kicking is an important skill in Australian Football (AF). This study examined whether kinematic differences exist between accurate and inaccurate goal-kicks and determined the relationships between technical factors and accuracy. Eighteen elite to sub-elite AF players performed 15 x 30 m goal-kicks on an AF training ground, with three-dimensi...

The purpose is to provide an overview of the externally measured movement characteristics of Australian Football League Women's (AFLW) competition, and the variability in this between matches. A range of movement variables were measured from 28 athletes who wore 10 Hz GPS devices during games and were summarized according to positional groups. The...

Johnston, RD, Thornton, HR, Wade, JA, Devlin, P, and Duthie, GM. The distribution of match activities relative to the maximal mean intensities in professional rugby league and Australian football. J Strength Cond Res XX(X): 000-000, 2020-This study determined the distribution of distance, impulse, and accelerometer load accumulated at intensities r...

Duthie, GM, Thomas, EJ, Bahnisch, J, Thornton, HR, and Ball, K. Using small-sided games in field hockey: Can they be used to reach match intensity? J Strength Cond Res XX(X): 000-000, 2019-Small-sided games (SSGs) are commonly used in field hockey to replicate or overload physical and tactical competition demands; however, little evidence is availa...

Previous research has quantified the peak movement demands of elite rugby league match-play, but the peak accelerometer load or the semi-professional peak demands remain unknown. The aim of this research was to determine the peak movement demands of professional and semi-professional rugby league competition. Wearable microtechnology devices tracke...

Professional sporting clubs invest in pathway programs, attempting to develop physical, technical abilities and psychological skills within a long-term framework (1,2), aiming to retain these athletes for selection in their senior teams. Often, youth teams will train separately within specified age groups, however, from a physical preparation persp...

Objectives: To investigate the peak accelerometer-derived intensity of state-level netball matches and compare differences between positional groupings. Findings will provide guidance for sport science professionals on how to best replicate the most intense passages of play in training settings. Design: Longitudinal (one season). Method: Twent...

Johnston, RD, Murray, NB, Austin, DJ, and Duthie, G. Peak movement and technical demands of professional Australian football competition. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to determine the average peak movement and technical demands of professional Australian football (AF) across a number of period durations using a...

To quantify the peak movement and contact demands of National Rugby League (NRL) and European Super League (ESL) competition players were tracked during 10 NRL (166 files) and 10 ESL (143 files) matches using microtechnology devices. The peak 1- to 5-min periods were then calculated for average match speed (m·min⁻¹), and acceleration (m·s⁻²) when 0...

Team-sport | GPS | AFL | rugby league | training load Headline F or monitoring and prescribing high-speed running, practitioners may use pre-defined (absolute) or individualised (relative) speed thresholds (1-3). Research has demonstrated clear differences in the total distance covered above a pre-defined threshold (high speed; HSD) using either ab...

Delves, RIM, Bahnisch, J, Ball, K, and Duthie, GM. Quantifying mean peak running intensities in elite field hockey. J Strength Cond Res 35(9): 2604-2610, 2021-To replicate match demands in training, field hockey (FH) coaches typically prescribe intensities based on whole-match data. Such data may underestimate peak competition periods, potentially...

The recent development of global navigation network systems (GNSS) has improved the availability and signal strength of surrounding satellites compared to traditional global positioning systems (GPS), although their ability to quantify rapid changes in speed may still be limited. This study aimed to evaluate the validity of GNSS to quantify the mea...

Within professional team sports, the collection and analysis of athlete monitoring data is common practice in the aim of assessing fatigue and subsequent adaptation responses, examining performance potential as well as minimizing the risk of injury and/or illness. Athlete monitoring systems should be underpinned by appropriate data analysis and int...

Abstract Graham, S, Duthie, G, Aughey, R, and Zois, J. Comparison of physical profiles of state-level netball players by position. J Strength Cond Res XX(X): 000–000, 2019—Understanding the physical profiles of state-level netball athletes provides conditioning professionals with testing norms and an understanding of important capacities within par...

Abstract Johnston, RD, Hewitt, A, and Duthie, G. Validity of real-time ultra-wideband global navigation satellite system data generated by a wearable microtechnology unit. J Strength Cond Res XX(X): 000–000, 2019—This study aimed to determine the validity of real-time ultra-wideband data generated by a wearable microtechnology unit during rugby lea...

Goal-kicks are taken from different positions during a game in Australian Football (AF), which can influence the difficulty of scoring a goal. This study examined the effect of altering kicking distance on goal-kicking technique in 18 AF players. Players performed 10 goal-kicks from 30 m and 40 m directly in-front of goals and kicking kinematics we...

Purpose: To establish the inter-unit reliability of a range of Global Positioning System (GPS)-derived movement indicators, determine the variation between manufacturers, and investigate the difference between software-derived and raw data. Methods: A range of movement variables were obtained from 27 GPS units from three manufacturers (GPSports...

The primary purpose of this study was to determine if a difference existed between peak speed attained when performing a sprint with maximal acceleration versus from a gradual build-up. Additionally, this investigation sought to compare the actual peak speed achieved when instructed to reach 75% and 90% of maximum speed. Field sport athletes (n = 2...

Duthie, GM, Thornton, HR, Delaney, JA, Connolly, DR, and Serpiello, FR. Running intensities in elite youth soccer by age and position. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this investigation was to examine differences between the peak running speed, acceleration, and metabolic power of elite youth soccer across a range of age lev...

The aim of the present study was to investigate the occurrence of Repeated High-Acceleration Ability (RHAA) bouts in elite youth football games using 10-Hz GPS devices and two relative thresholds derived from players’ actual maximal acceleration. Thirty-six outfield soccer players (age 14.9±0.6 years) participated in the study. Players wore 10-Hz G...

Wearable inertial measurement systems (IMS) allow for three-dimensional analysis of human movements in a sport-specific setting. This study examined the concurrent validity of a IMS (Xsens MVN system) for measuring lower extremity and pelvis kinematics in comparison to a Vicon motion analysis system (MAS) during kicking. Thirty footballers from Aus...

https://sportperfsci.com/training-efficiency-and-athlete-wellness-in-collegiate-female-soccer/

Purpose: Determine the relationship between drill type and accelerometer-derived loads during various team sport activities, and examine the influence of unit fitting on these loads. Methods: Sixteen rugby league players were fitted with microtechnology devices in either manufacturer vests or playing jerseys before completing standardised runnin...

Objective: To establish whether a simple integration of selected internal and external training load (TL) metrics is useful for tracking and assessing training outcomes during team-sport training. Methods: Internal [heart rate training impulse (HR-TRIMP), session rating of perceived exertion (sRPE-TL)] and selected external (global positioning syst...

The validity of an Ultra-wideband (UWB) positioning system was investigated during linear and change-of- direction (COD) running drills. Six recreationally-active men performed ten repetitions of four activities (walking, jogging, maximal acceleration, and 45o COD) on an indoor court. Activities were repeated twice, in the centre of the court and o...

The purpose of this study was to examine the relationship between individual athletes' physical characteristics and both the peak running intensities and the decline in peak running intensities during competition. Twenty-two professional rugby league athletes (age; 24.1 ± 4.0 years, body mass; 101.4 ± 9.5 kg) underwent a series of physical testing...

The present study observed within-week fluctuations in both sIgA and sCort concentrations that corresponded with weekly increases in TD as shown in Figure 1. However, when examining the individual within-week salivary responses and the workload undergone (see Figure 2), these relationships were limited. Specifically, an increase in TD between the t...

Purpose: This study determined differences in prolonged high-intensity running (PHIR) performance and running momentum (pIFT) between competition levels and positional groups in rugby league. Methods: Elite Australian National Rugby League (NRL), sub-elite [state-based competition (SRL); National Youth Competition (NYC); local league (LL)] and juni...

Purpose: To investigate the influence of daily and exponentially-weighted moving training loads on subsequent night-time sleep. Methods: Sleep of fourteen professional rugby league athletes competing in the National Rugby League competition was recorded using wristwatch actigraphy. Physical demands were quantified using GPS technology, including...

Knowledge of the most intense periods of competitive soccer may assist in the development of specific training methodologies. Objectives: To quantify the peak running intensity of professional soccer and to establish the rate of decline in this intensity as a function of time. Methods: Activity profiles were obtained from 24 players across 40 profe...

The ability to accelerate, decelerate and change direction efficiently is imperative to successful team-sports performance. Traditional intensity-based thresholds for acceleration and deceleration may be inappropriate for time-series data, and have been shown to exhibit poor reliability, suggesting other techniques may be preferable. This study ass...

Objectives: To establish the position and duration-specific running demands of Australian Football (AF) competition for the prescription and monitoring of specific training drills. Design: An observational time-motion analysis was performed on 40 professional AF players during 30 games throughout the 2014-15 competitive seasons. Methods: Playe...

Purpose: To quantify the duration and position-specific peak running intensities of international rugby union, for the prescription and monitoring of specific training methodologies. Methods: Global positioning systems (GPS) were used to assess the activity profile of 67 elite-level rugby union players from two separate nations, across 33 intern...

Purpose: To investigate the effects of a training camp on the sleep characteristics of professional rugby league players compared to a home period. Methods: During a seven-day home and 13-day camp period, time in bed (TIB), total sleep time (TST), sleep efficiency (SE) and wake after sleep onset (WASO) were measured using wristwatch actigraphy....

INTRODUCTION: Professional sporting teams often undergo high-intensity training camps to impose intensified training loads (TL) to maximise adaptations prior to competition. However, evidence suggests that team-sport athletes often experience poorer sleep during training camps, which may be attributed to the heightened TL's and/or different sleep e...

The influence of training load on markers of fatigue in junior male semi-elite sailors

Relationships between the speed bound index and key performance indicators in professional rugby league

Modeling peak running intensity in football

This study examined the validity of the 30-15 Intermittent Fitness Test (30-15IFT) within rugby league. Sixty-three Australian elite and junior-elite rugby league players (22.5 ± 4.5 yr, 96.1. kg ± 9.5 kg, Σ7 skinfolds: 71.0 ± 18.7 mm) from a professional club participated in this study. Players were assessed for anthropometry (body mass, Σ7 skinfo...

Abstract Purpose: To investigate the ability of various internal and external training load (TL) monitoring measures to predict injury incidence amongst positional groups within professional rugby league athletes. Methods: TL and injury data were collected across 3 seasons (2013-2015) from twenty-five players competing in the National Rugby League...

Resistance exercise is difficult to quantify owing to its inherent complexity with numerous training variables contributing to the training dose (type of exercise, load lifted, training volume, inter-set rest periods, and repetition velocity). In addition, the intensity of resistance training is often inadequately determined as the relative load li...

Purpose: To assess the independent factors affecting running intensity sustained by interchange players during professional rugby league. Methods: Global positioning system (GPS) data were collected from all interchanged players (starters and non-starters) within a professional rugby league squad across 20 matches of a National Rugby League (NRL...

Purpose: To quantify the energetic cost of running and acceleration efforts during rugby league competition to aid in prescription and monitoring of training. Methods: Global Positioning System (GPS) data were collected from 37 professional rugby league players across two seasons. Peak values for relative distance, average acceleration/decelerat...

Purpose: The aim of this study was to identify contributing factors to the incidence of illness for professional team-sport athletes, utilizing training load (TL), self-reported illness and wellbeing data. Methods: Thirty-two professional rugby league players (26.0 ± 4.8 yr; 99.1 ± 9.6 kg; 1.84 ± 0.06 m) were recruited from the same club. Player...

High levels of lean mass are important for collision-based sports, for the development of strength and power, which may also assist during contact situations. Whilst skinfold-based measures have been shown to be appropriate for cross-sectional assessments of body composition, their utility in tracking changes in lean mass is less clear. To determin...

High levels of lean mass are important for collision-based sports, for the development of strength and power, which may also assist during contact situations. Whilst skinfold-based measures have been shown to be appropriate for cross-sectional assessments of body composition, their utility in tracking changes in lean mass is less clear. Purpose: To...

This study examined the reliability and usefulness of the 30-15 Intermittent Fitness Test (30-15IFT) within rugby league. Fifty-five young rugby league players participated in the study. These included representative players from Under 16's (n=19, 15.6 +/- 0.3 yr, 78.1 kg +/- 10.9 kg), Under 18's (n=21, 17.4 +/- 0.5 yr, 86.9 +/- 11.2 kg) and Under...

Rugby league coaches often prescribe training to replicate the demands of competition. The intensities of running drills are often monitored in comparison to absolute match-play measures. Such measures may not be sensitive enough to detect fluctuations in intensity across a match, or to differentiate between positions. To determine the position- an...

Rugby league is an intermittent team sport in which players are regularly required to accelerate, decelerate, and change direction rapidly. This study aimed to determine the contributing factors to change-of-direction (COD) ability in professional rugby league players, and secondly, to validate the physical and physiological components of a previou...

Time motion analysis is extensively used to assess the demands of team sports. At present there is only limited information on the reliability of measurements using this analysis tool. The aim of this study was to establish the reliability of an individual observer's time motion analysis of rugby union. Ten elite level rugby players were individual...

The aim of this study was to characterize relationships between anthropometric and isoinertial strength characteristics and bowling speed in junior and senior cricket fast bowlers. Subjects were first-class senior (n = 24; mean +/- SD age = 23.9 +/- 4.8 years, height = 187.4 +/- 4.8 cm, mass = 87.8 +/- 8.4 kg) and junior representative (n = 48; mea...

Acceleration is an important factor for success in team-sport athletes. The purpose of this investigation was to compare the reliability of 10-m sprint times when using different starting techniques. Junior male rugby players (n = 15) were tested for speed over 10 m on 2 different testing sessions. Three trials of 3 different starting techniques (s...

Increased professionalism in rugby has resulted in national unions developing high-performance models for elite player development, of which physical preparation is an important component, to ensure success in future years. This article presents a 5-step framework for the physical preparation of elite players in a development program. Competition m...

To demonstrate the utility of a practical measure of lean mass for monitoring changes in the body composition of athletes. Between 1999 and 2003 body mass and sum of seven skinfolds were recorded for 40 forwards and 32 backs from one Super 12 rugby union franchise. Players were assessed on 13 (7) occasions (mean (SD)) over 1.9 (1.3) years. Mixed mo...

The lean mass index (LMI) is a new empirical measure that tracks within-subject proportional changes in body mass adjusted for changes in skinfold thickness. To compare the ability of the LMI and other skinfold derived measures of lean mass to monitor changes in lean mass. 20 elite rugby union players undertook full anthropometric profiles on two o...

The purpose of this study was to characterize sprint patterns of rugby union players during competition. Velocity profiles (60 m) of 28 rugby players were initially established in testing from standing, walking, jogging, and striding starts. During competition, the individual sprinting patterns of 17 rugby players were determined from video by usin...

The aim of this study was to quantify movements of Super 12 rugby players in competition because information on elite rugby players' movements is unavailable. Players were categorized into forwards [front (n = 16) and back row (n = 15)] and backs [inside (n = 9) and outside backs (n = 7)] and their movements analysed by video-based time motion anal...