ORCID Profile
0000-0002-5818-4450
Current Organisation
University of Newcastle Australia
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Publisher: Human Kinetics
Date: 08-2017
Abstract: To investigate the effects of a training c on the sleep characteristics of professional rugby league players compared with a home period. During a 7-d home and 13-d c period, time in bed (TIB), total sleep time (TST), sleep efficiency (SE), and wake after sleep onset were measured using wristwatch actigraphy. Subjective wellness and training loads (TL) were also collected. Differences in sleep and TL between the 2 periods and the effect of daytime naps on nighttime sleep were examined using linear mixed models. Pearson correlations assessed the relationship of changes in TL on in iduals’ TST. During the training c , TST (–85 min), TIB (–53 min), and SE (–8%) were reduced compared with home. Those who undertook daytime naps showed increased TIB (+33 min), TST (+30 min), and SE (+0.9%). Increases in daily total distance and training duration above in idual baseline means during the training c shared moderate ( r = –.31) and trivial ( r = –.04) negative relationships with TST. Sleep quality and quantity may be compromised during training c s however, daytime naps may be beneficial for athletes due to their known benefits, without being detrimental to nighttime sleep.
Publisher: Informa UK Limited
Date: 10-10-2019
DOI: 10.1080/17461391.2018.1527949
Abstract: To characterize player core temperature (Tc) across two separate World Rugby Sevens Series (WRSS) tournaments in temperate and warm environments. Tc was collected in seventeen playing members of one men's team competing at the Singapore (n = 12) and London (n = 11) WRSS tournaments. Exertional heat illness (EHI) symptoms, cooling strategy use, playing minutes and wet blub globe temperature (WBGT) were also collected. Linear mixed models and magnitude-based inferences assessed differences in Tc between all periods within-and between tournaments and were also used to assess the effect of WBGT and playing minutes on Tc. Several players experienced Tc in excess of 38°C during warm-ups and 39°C during games. The highest mean Tc values were observed in the final game on all days and in Singapore Day Two, there were substantial game-on-game increases in mean Tc. These Tc responses were associated with playing minutes (effect size ±90% CL = 0.38 ±0.20), although the effect of WBGT was trivial and unclear. Further, there were no differences in Tc between the two tournaments in the different environments. Despite high in idual peak Tc values (Singapore 39.9°C London 39.6°C) no signs/symptoms of EHI were reported, voluntary post-game cooling usage was minimal, and pre- and mid-cooling strategies were not implemented. During WRSS matches, peak Tc values approached thresholds associated with EHI (>40°C) and exceeded those demonstrated to reduce repeated sprint performance (>39°C). Practitioners may consider the use of compatible cooling and heat acclimation strategies to minimize Tc increase and maximize player preparedness and recovery.
Publisher: Human Kinetics
Date: 02-2020
Abstract: Sprint capacity is an important attribute for team-sport athletes, yet the most appropriate method to analyze it is unclear. Purpose : To examine the relationship between sprint workloads using relative versus absolute thresholds and lower-body soft-tissue and bone-stress injury incidence in professional Australian rules football. Methods : Fifty-three professional Australian rules football athletes’ noncontact soft-tissue and bone-stress lower-body injuries (N = 62) were recorded, and sprint workloads were quantified over ∼18 months using the global positioning system. Sprint volume (m) and exposures (n) were determined using 2 methods: absolute ( .9 km·h −1 ) and relative (≥75%, ≥80%, ≥85%, ≥90%, ≥95% of maximal velocity). Relationships between threshold methods and injury incidence were assessed using logistic generalized additive models. Incidence rate ratios and model performances’ area under the curve were reported. Results : Mean (SD) maximal velocity for the group was 31.5 (1.4), range 28.6 to 34.9 km·h −1 . In comparing relative and absolute thresholds, 75% maximal velocity equated to ~1.5 km·h −1 below the absolute speed threshold, while 80% and 85% maximal velocity were 0.1 and 1.7 km·h −1 above the absolute speed threshold, respectively. Model area under the curve ranged from 0.48 to 0.61. Very low and very high cumulative sprint loads ≥80% across a 4-week period, when measured relatively, resulted in higher incidence rate ratios (2.54–3.29), than absolute thresholds (1.18–1.58). Discussion : Monitoring sprinting volume relative to an athlete’s maximal velocity should be incorporated into athlete monitoring systems. Specifically, quantifying the distance covered at % maximal velocity will ensure greater accuracy in determining sprint workloads and associated injury risk.
Publisher: Public Library of Science (PLoS)
Date: 19-11-2021
DOI: 10.1371/JOURNAL.PONE.0260363
Abstract: 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, National Rugby League [NRL] n = 26, 21 matches). To quantify manoeuvrability, tortuosity was calculated from the X and Y coordinates from match GNSS files (converted from latitude and longitude). Tortuosity was calculated as 100 x natural logarithm of the chord distance (distance travelled between X and Y coordinates), ided by the straight-line distance. The maximal tortuosity was then quantified for each 0.5 m∙s -1 speed increment, ranging from 0 to the highest value for each game file. A quadratic model was fitted for each match file, controlling for the curvilinear relationship between tortuosity and velocity. A comparison of the quadratic coefficients between sports, and within sport between positions was investigated using linear mixed models. Resulting standard deviations (SDs) and mean differences were then assessed to establish standardized effect sizes (ES) and 90% confidence intervals (CI). A curvilinear relationship exists between maximal tortuosity and running speed, reflecting that as speed increases, athletes’ ability to deviate from a linear path is compromised (i.e., run in a more linear path). Compared to AFL, NRL had a greater negative quadratic coefficient ( a ) (ES = 0.70 0.47 to 0.93) for the 5 second analysis, meaning that as speed increased, NRL athletes’ manoeuvrability reduced at a faster rate than when compared to AFL. There were no positional differences within each sport. GNSS derived information can be used to provide a measure of manoeuvrability tortuosity during NRL and AFL matches. The curvilinear relationship between tortuosity and speed demonstrated that as speed increased, manoeuvrability was compromised.
Publisher: Human Kinetics
Date: 10-2023
Abstract: Purpose : There has been a proliferation in technologies in the sport performance environment that collect increasingly larger quantities of athlete data. These data have the potential to be personal, sensitive, and revealing and raise privacy and confidentiality concerns. A solution may be the use of synthetic data, which mimic the properties of the original data. The aim of this study was to provide ex les of synthetic data generation to demonstrate its practical use and to deploy a freely available web-based R Shiny application to generate synthetic data. Methods : Openly available data from 2 previously published studies were obtained, representing typical data sets of (1) field- and gym-based team-sport external and internal load during a preseason period (n = 28) and (2) performance and subjective changes from before to after the posttraining intervention (n = 22). Synthetic data were generated using the synthpop package in R Studio software, and comparisons between the original and synthetic data sets were made through Welch t tests and the distributional similarity standardized propensity mean squared error statistic. Results : There were no significant differences between the original and more synthetic data sets across all variables examined in both data sets ( P .05). Further, there was distributional similarity (ie, low standardized propensity mean squared error) between the original observed and synthetic data sets. Conclusions : These findings highlight the potential use of synthetic data as a practical solution to privacy and confidentiality issues. Synthetic data can unlock previously inaccessible data sets for exploratory analysis and facilitate multiteam or multicenter collaborations. Interested sport scientists, practitioners, and researchers should consider utilizing the shiny web application (SYNTHETIC DATA—available at assetlab.shinyapps.io/SyntheticData/ ).
Publisher: Human Kinetics
Date: 04-2021
Abstract: Purpose : To assess the efficacy of a combined light exposure and sleep hygiene intervention to improve team-sport performance following eastward long-haul transmeridian travel. Methods : Twenty physically trained males underwent testing at 09:00 and 17:00 hours local time on 4 consecutive days at home (baseline) and the first 4 days following 21 hours of air travel east across 8 time zones. In a randomized, matched-pairs design, participants traveled with (INT n = 10) or without (CON n = 10) a light exposure and sleep hygiene intervention. Performance was assessed via countermovement jump, 20-m sprint, T test, and Yo-Yo Intermittent Recovery Level 1 tests, together with perceptual measures of jet lag, fatigue, mood, and motivation. Sleep was measured using wrist activity monitors in conjunction with self-report diaries. Results : Magnitude-based inference and standardized effect-size analysis indicated there was a very likely improvement in the mean change in countermovement jump peak power (effect size 1.10, ±0.55), and likely improvement in 5-m (0.54, ±0.67) and 20-m (0.74, ±0.71) sprint time in INT compared with CON across the 4 days posttravel. Sleep duration was most likely greater in INT both during travel (1.61, ±0.82) and across the 4 nights following travel (1.28, ±0.58) compared with CON. Finally, perceived mood and motivation were likely worse (0.73, ±0.88 and 0.63, ±0.87) across the 4 days posttravel in CON compared with INT. Conclusions : Combined light exposure and sleep hygiene improved speed and power but not intermittent-sprint performance up to 96 hours following long-haul transmeridian travel. The reduction of sleep disruption during and following travel is a likely contributor to improved performance.
Publisher: Human Kinetics
Date: 09-2015
Abstract: Rugby league coaches often prescribe training to replicate the demands of competition. The intensities of running drills are often monitored in comparison with 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- and duration-specific running intensities of rugby league competition, using a moving-average method, for the prescription and monitoring of training. Data from a 15-Hz global positioning system (GPS) were collected from 32 professional rugby league players across a season. The velocity–time curve was analyzed using a rolling-average method, where maximum values were calculated for 10 different durations, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 min, for each player across each match. There were large differences between the 1- and 2-min rolling averages and all other rolling-average durations. Smaller differences were observed for rolling averages of greater duration. Fullbacks maintained a greater velocity than outside backs and middle and edge forwards over the 1- and 2-min rolling averages (ES 0.8−1.2, P .05). For rolling averages 3 min and greater, the running demands of the fullbacks were greater than those of the middle forwards and outside backs (ES 1.1−1.4, P .05). These findings suggest that the running demands of rugby league fluctuate vastly across a match. Fullbacks were the only position to exhibit a greater running intensity than any other position, and therefore training prescription should reflect this.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2017
DOI: 10.1519/JSC.0000000000001849
Abstract: Delaney, JA, Cummins, CJ, Thornton, HR, and Duthie, GM. Importance, reliability and usefulness of acceleration measures in team sports. J Strength Cond Res 32(12): 3494–3502, 2018—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 assessed movement data from one professional rugby league team throughout 2 full seasons and 1 preseason period. Using both 5 and 10 Hz global positioning systems (GPS) units, a range of acceleration-based variables were evaluated for their interunit reliability, ability to discriminate between positions, and associations with perceived muscle soreness. The reliability of 5 Hz global positioning systems for measuring acceleration and deceleration ranged from good to poor (CV = 3.7–27.1%), with the exception of high-intensity deceleration efforts (CV = 11.1–11.8%), the 10 Hz units exhibited moderate-to-good interunit reliability (CV = 1.2–6.9%). Reliability of average metrics (average acceleration/deceleration, average acceleration, and average deceleration) ranged from good to moderate (CV = 1.2–6.5%). Substantial differences were detected between positions using time spent accelerating and decelerating for all magnitudes, but these differences were less clear when considering the count or distance above acceleration/deceleration thresholds. All average metrics detected substantial differences between positions. All measures were similarly related to perceived muscle soreness, with the exception of high-intensity acceleration and deceleration counts. This study has proposed that averaging the acceleration/deceleration demands over an activity may be a more appropriate method compared with threshold-based methods, because a greater reliability between units, while not sacrificing sensitivity to within-subject and between-subject changes.
Publisher: Human Kinetics
Date: 10-2019
Abstract: Purpose : To determine how a cooling vest worn during a warm-up could influence selected performance (countermovement jump [CMJ]), physical (global positioning system [GPS] metrics), and psychophysiological (body temperature and perceptual) variables. Methods : In a randomized, crossover design, 12 elite male World Rugby Sevens Series athletes completed an outdoor (wet bulb globe temperature 23–27°C) match-specific externally valid 30-min warm-up wearing a phase-change cooling vest (VEST) and without (CONTROL), on separate occasions 7 d apart. CMJ was assessed before and after the warm-up, with GPS indices and heart rate monitored during the warm-ups, while core temperature ( T c ingestible telemetric pill n = 6) was recorded throughout the experimental period. Measures of thermal sensation (TS) and thermal comfort (TC) was obtained pre-warm-up and post-warm-up, with rating of perceived exertion (RPE) taken post-warm-ups. Results : Athletes in VEST had a lower Δ T c (mean [SD]: VEST = 1.3°C [0.1°C] CONTROL = 2.0°C [0.2°C]) from pre-warm-up to post-warm-up (effect size ±90% confidence limit: −1.54 ±0.62) and T c peak (mean [SD]: VEST = 37.8°C [0.3°C] CONTROL = 38.5°C [0.3°C]) at the end of the warm-up (−1.59 ±0.64) compared with CONTROL. Athletes in VEST demonstrated a decrease in ΔTS (−1.59 ±0.72) and ΔTC (−1.63 ±0.73) pre-warm-up to post-warm-up, with a lower RPE post-warm-up (−1.01 ±0.46) than CONTROL. Changes in CMJ and GPS indices were trivial between conditions (effect size 0.2). Conclusions : Wearing the vest prior to and during a warm-up can elicit favorable alterations in physiological ( T c ) and perceptual (TS, TC, and RPE) warm-up responses, without compromising the utilized warm-up characteristics or physical-performance measures.
Publisher: Human Kinetics
Date: 07-2019
Abstract: In professional team sports, the collection and analysis of athlete-monitoring data are common practice, with the aim of assessing fatigue and subsequent adaptation responses, examining performance potential, and minimizing the risk of injury and/or illness. Athlete-monitoring systems should be underpinned by appropriate data analysis and interpretation, to enable the rapid reporting of simple and scientifically valid feedback. Using the correct scientific and statistical approaches can improve the confidence of decisions made from athlete-monitoring data. However, little research has discussed and proposed an outline of the process involved in the planning, development, analysis, and interpretation of athlete-monitoring systems. This review discusses a range of methods often employed to analyze athlete-monitoring data to facilitate and inform decision-making processes. There is a wide range of analytical methods and tools that practitioners may employ in athlete-monitoring systems, as well as several factors that should be considered when collecting these data, methods of determining meaningful changes, and various data-visualization approaches. Underpinning a successful athlete-monitoring system is the ability of practitioners to communicate and present important information to coaches, ultimately resulting in enhanced athletic performance.
Publisher: Human Kinetics
Date: 05-0005
Abstract: To identify contributing factors to the incidence of illness for professional team-sport athletes, using training load (TL), self-reported illness, and well-being data. Thirty-two professional rugby league players (26.0 ± 4.8 y, 99.1 ± 9.6 kg, 1.84 ± 0.06 m) were recruited from the same club. Players participated in prescribed training and responded to a series of questionnaires to determine the presence of self-reported illness and markers of well-being. Internal TL was determined using the session rating of perceived exertion. These data were collected over 29 wk, across the preparatory and competition macrocycles. The predictive models developed recognized increases in internal TL (strain values of AU, weekly TL AU, and monotony .78 AU) to best predict when athletes are at increased risk of self-reported illness. In addition, a reduction in overall well-being ( .25 AU) in the presence of increased internal TL, as previously stated, was highlighted as a contributor to self-reported-illness occurrence. These results indicate that self-report data can be successfully used to provide a novel understanding of the interactions between competition-associated stressors experienced by professional team-sport athletes and their susceptibility to illness. This may help coaching staff more effectively monitor players during the season and potentially implement preventive measures to reduce the likelihood of illnesses occurring.
Publisher: Informa UK Limited
Date: 03-11-2018
DOI: 10.1080/02640414.2017.1398883
Abstract: Currently, very little is known about the impact of short- or long-haul air travel on the sleep and wellbeing of wheelchair basketball athletes. Eleven national wheelchair basketball athletes wore actigraphy monitors prior, during, and after air travel to the United Kingdom. Upon arrival, participants rated their subjective jet-lag, fatigue, and vigor. In iduals traveled to the United Kingdom from different locations in Australia, the United States, and Europe and were categorised according to travel length [LONG (up to 30.2 h) or SHORT (up to 6.5 h)]. Linear mixed models determined effects of travel length on sleep and subjective ratings of jet-lag, fatigue, and vigor. During competition, subjective fatigue and jet-lag were substantially higher (ES = 0.73 ±0.77) and (ES = 0.57 ±0.60), subjective vigor was lower (ES = 1.94 ±0.72), and get-up time was earlier (ES = 0.57 ±0.60) for LONG when compared to SHORT. Travelling greater distances by airplane had a larger effect on subjective ratings of jet-lag, fatigue and vigor, rather than sleep. Irrespective of travel group, sleep and subjective responses were compromised, reflecting the travel requirements, competition-mediated influences, and/or due to a change in environment.
Publisher: Human Kinetics
Date: 08-2018
Abstract: Context : Team-sport training requires the daily manipulation of intensity, duration, and frequency, with preseason training focusing on meeting the demands of in-season competition and training on maintaining fitness. Purpose : To provide information about daily training in Australian football (AF), this study aimed to quantify session intensity, duration, and intensity distribution across different stages of an entire season. Methods : Intensity (session ratings of perceived exertion CR-10 scale) and duration were collected from 45 professional male AF players for every training session and game. Each session’s rating of perceived exertion was categorized into a corresponding intensity zone, low ( .0 arbitrary units), moderate (≥4.0 and .0), and high (≥7.0), to categorize session intensity. Linear mixed models were constructed to estimate session duration, intensity, and distribution between the 3 preseason and 4 in-season periods. Effects were assessed using linear mixed models and magnitude-based inferences. Results : The distribution of the mean session intensity across the season was 29% low intensity, 57% moderate intensity, and 14% high intensity. While 96% of games were high intensity, 44% and 49% of skills training sessions were low intensity and moderate intensity, respectively. Running had the highest proportion of high-intensity training sessions (27%). Preseason displayed higher training-session intensity (effect size [ES] = 0.29–0.91) and duration (ES = 0.33–1.44), while in-season game intensity (ES = 0.31–0.51) and duration (ES = 0.51–0.82) were higher. Conclusion s : By using a cost-effective monitoring tool, this study provides information about the intensity, duration, and intensity distribution of all training types across different phases of a season, thus allowing a greater understanding of the training and competition demands of Australian footballers.
Publisher: Springer Science and Business Media LLC
Date: 16-01-2016
DOI: 10.1007/S40279-015-0454-0
Abstract: 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 lifted (% 1-repetition maximum), which does not account for the effects of inter-set recovery periods, repetition velocity, or the number of repetitions performed in each set at a given load. Methods to calculate the volume load associated with resistance training, as well as the perceived intensity of in idual sets and entire training sessions have been shown to provide useful information regarding the actual training stimulus. In addition, questionnaires to subjectively assess how athletes are coping with the stressors of training and portable technologies to quantify performance variables such as concentric velocity may also be valuable. However, while several methods have been proposed to quantify resistance training, there is not yet a consensus regarding how these methods can be best implemented and integrated to complement each other. Therefore, the purpose of this review is to provide practical information for strength coaches to highlight effective methods to assess resistance training, and how they can be integrated into a comprehensive monitoring program.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 27-11-2019
DOI: 10.1519/JSC.0000000000003445
Abstract: 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 36(2): 498–502, 2022—Small-sided games (SSGs) are commonly used in field hockey to replicate or overload physical and tactical competition demands however, little evidence is available regarding if specific SSG formats achieve this. This research investigated how speed and acceleration differed between 5-minute SSG formats (2v2, 3v3, and 4v4) and also compared with competition. Elite male field hockey athletes ( n = 10) participated in the SSGs with standard rules, on pitches of 30 × 20, 35 × 25, and 40 × 30 m, respectively (∼150 m 2 per athlete excluding goal keepers). Global Positioning System devices measured speed (m·min −1 ) and acceleration (m·s −2 ). Differences between mean speed and acceleration during SSGs and 5-minute maximal mean values from competition (calculated using moving averages) were quantified using linear mixed models and described using standardized effect sizes (ES) and 90% confidence intervals. Between SSG formats, there were nonsubstantial differences for mean speed and acceleration (ES range −0.4 to 0.8). Compared with competition, mean speed was substantially lower for all SSG formats (ES range −1.4 to −1.8), whereas mean acceleration was higher (ES range 3.9–4.8). The SSG formats examined had a lower mean speed and higher mean acceleration than the maximal mean observed in competition. Therefore, these SSGs are an effective training drill for the development and overload of acceleration. However, manipulating SSG constraints to expose athletes to the maximal mean competition speed is required.
Publisher: Informa UK Limited
Date: 10-02-2019
Publisher: Human Kinetics
Date: 11-2016
Abstract: Rugby league coaches adopt replacement strategies for their interchange players to maximize running intensity however, it is important to understand the factors that may influence match performance. To assess the independent factors affecting running intensity sustained by interchange players during professional rugby league. Global positioning system (GPS) data were collected from all interchanged players (starters and nonstarters) in a professional rugby league squad across 24 matches of a National Rugby League season. A multilevel mixed-model approach was employed to establish the effect of various technical (attacking and defensive involvements), temporal (bout duration, time in possession, etc), and situational (season phase, recovery cycle, etc) factors on the relative distance covered and average metabolic power (P met ) during competition. Significant effects were standardized using correlation coefficients, and the likelihood of the effect was described using magnitude-based inferences. Superior intermittent running ability resulted in very likely large increases in both relative distance and P met . As the length of a bout increased, both measures of running intensity exhibited a small decrease. There were at least likely small increases in running intensity for matches played after short recovery cycles and against strong opposition. During a bout, the number of collision-based involvements increased running intensity, whereas time in possession and ball time out of play decreased demands. These data demonstrate a complex interaction of in idual- and match-based factors that require consideration when developing interchange strategies, and the manipulation of training loads during shorter recovery periods and against stronger opponents may be beneficial.
Publisher: Informa UK Limited
Date: 14-03-2022
DOI: 10.1080/24733938.2022.2051729
Abstract: 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
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2017
DOI: 10.1519/JSC.0000000000002273
Abstract: Duthie, GM, Thornton, HR, Delaney, JA, McMahon, JT, and Benton, DT. Relationship between physical performance testing results and peak running intensity during professional rugby league match play. J Strength Cond Res 34(12): 3506–3513, 2020—The purpose of this study was to examine the relationship between in idual 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 procedures. Peak running intensity was determined using a moving average technique, applied to the speed (m·min −1 ), acceleration/deceleration (m·s −2 ), and metabolic power (W·kg −1 ) during competition, across 10 different durations. The power law relationship was then established, yielding an intercept and slope for the movement variables. Mixed linear models were then used to determine the relationship between physical characteristics and intercept and slope values. There were large, positive relationships between a player's maximal speed and both peak running speeds (effect size = 0.56, 90% confidence interval: 0.20–0.78) and metabolic power (0.57, 0.21–0.79) during competition. By contrast, there were large, negative associations between maximal speed and the rate of decline in running speed (−0.60, −0.81 to −0.27) and metabolic power (−0.65, −0.83 to −0.32) during competition. Similarly, there were negative associations between relative squat strength and the rate of decline in running speed (moderate: −0.41, −0.69 to −0.04) and metabolic power (large: −0.53, −0.77 to −0.17) during competition. The findings of this study demonstrate that a players running intensity during competition is underpinned by the in idual athletes physiological qualities. Athletes demonstrating higher maximal speeds in testing were able to maintain higher running intensities over short durations but had a greater decrease in running intensity as duration increased.
Publisher: Informa UK Limited
Date: 31-10-2018
DOI: 10.1080/02640414.2017.1398885
Abstract: This study examined agreement between self-perceived sleep and sleep estimated via activity monitors in professional rugby league athletes. 63 athletes, from three separate teams wore actigraphy monitors for 10.3 ± 3.9 days. During the monitoring period, ratings of perceived sleep quality (on a 1-5 and 1-10 Likert scale), and an estimate of sleep duration were recorded daily. Agreement between sleep estimated via activity monitors and self-perceived sleep was examined using mean bias, Pearson correlation (r) and typical error of the estimate (TEE). 641 nights of sleep were recorded, with a very large, positive correlation observed between sleep duration estimated via activity monitors and subjective sleep duration (r = 0.85), and a TEE of 48 minutes. Mean bias revealed subjective sleep duration overestimated sleep by an average of 19.8 minutes. The relationship between sleep efficiency estimated via activity monitors and self-perceived sleep quality on a 1-5 (r = 0.22) and 1-10 Likert scale (r = 0.28) was limited. The outcomes of this investigation support the use of subjective measures to monitor sleep duration in rugby league athletes when objective means are unavailable. However, practitioners should be aware of the tendency of athletes to overestimate sleep duration.
Publisher: Human Kinetics
Date: 07-2017
Abstract: To investigate the ability of various internal and external training-load (TL) monitoring measures to predict injury incidence among positional groups in professional rugby league athletes. TL and injury data were collected across 3 seasons (2013–2015) from 25 players competing in National Rugby League competition. Daily TL data were included in the analysis, including session rating of perceived exertion (sRPE-TL), total distance (TD), high-speed-running distance ( m/s), and high-metabolic-power distance (HPD W/kg). Rolling sums were calculated, nontraining days were removed, and athletes’ corresponding injury status was marked as “available” or “unavailable.” Linear (generalized estimating equations) and nonlinear (random forest RF) statistical methods were adopted. Injury risk factors varied according to positional group. For adjustables, the TL variables associated most highly with injury were 7-d TD and 7-d HPD, whereas for hit-up forwards they were sRPE-TL ratio and 14-d TD. For outside backs, 21- and 28-d sRPE-TL were identified, and for wide-running forwards, sRPE-TL ratio. The in idual RF models showed that the importance of the TL variables in injury incidence varied between athletes. Differences in risk factors were recognized between positional groups and in idual athletes, likely due to varied physiological capacities and physical demands. Furthermore, these results suggest that robust machine-learning techniques can appropriately monitor injury risk in professional team-sport athletes.
Publisher: Human Kinetics
Date: 09-2017
Abstract: To quantify the duration and position-specific peak running intensities of international rugby union for the prescription and monitoring of specific training methodologies. Global positioning systems (GPS) were used to assess the activity profile of 67 elite-level rugby union players from 2 nations across 33 international matches. A moving-average approach was used to identify the peak relative distance (m/min), average acceleration/deceleration (AveAcc m/s 2 ), and average metabolic power (P met ) for a range of durations (1–10 min). Differences between positions and durations were described using a magnitude-based network. Peak running intensity increased as the length of the moving average decreased. There were likely small to moderate increases in relative distance and AveAcc for outside backs, halfbacks, and loose forwards compared with the tight 5 group across all moving-average durations (effect size [ES] = 0.27–1.00). P met demands were at least likely greater for outside backs and halfbacks than for the tight 5 (ES = 0.86–0.99). Halfbacks demonstrated the greatest relative distance and P met outputs but were similar to outside backs and loose forwards in AveAcc demands. The current study has presented a framework to describe the peak running intensities achieved during international rugby competition by position, which are considerably higher than previously reported whole-period averages. These data provide further knowledge of the peak activity profiles of international rugby competition, and this information can be used to assist coaches and practitioners in adequately preparing athletes for the most demanding periods of play.
Publisher: Human Kinetics
Date: 03-2017
Abstract: Purpose : To compare relative and absolute speed and metabolic thresholds for quantifying match output in elite rugby league. Methods : Twenty-six professional players competing in the National Rugby League were monitored with global positioning systems (GPS) across a rugby-league season. Absolute speed (moderate-intensity running [MIR Th 3.6 m/s] and high-intensity running [HIR Th 5.2 m/s]) and metabolic ( W/kg) thresholds were compared with in idualized ventilatory (first [VT 1IFT ] and second [VT 2IFT ]) thresholds estimated from the 30-15 Intermittent Fitness Test (30-15 IFT ), as well as the metabolic threshold associated with VT 2IFT (HP metVT2 ), to examine difference in match-play demands. Results : VT 2IFT mean values represent 146%, 138%, 167%, and 144% increases in the HIR dose across adjustables, edge forwards, middle forwards, and outside backs, respectively. Distance covered above VT 2IFT was almost certainly greater (ES range = 0.79–1.03) than absolute thresholds across all positions. Trivial to small differences were observed between VT 1IFT and MIR Th , while small to moderate differences were reported between HP metVT2 and HP metTh . Conclusions : These results reveal that the speed at which players begin to run at higher intensities depends on in idual capacities and attributes. As such, using absolute HIR speed thresholds underestimates the physical HIR load. Moreover, absolute MIR and high metabolic thresholds may over- or underestimate the work undertaken above these thresholds depending on the respective fitness of the in idual. Therefore, using relative thresholds enables better prescription and monitoring of external training loads based on measured in idual physical capacities.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2017
Publisher: Human Kinetics
Date: 2023
Publisher: SAGE Publications
Date: 24-01-2022
DOI: 10.1177/17479541211070789
Abstract: Monitoring athletes’ training may help prevent negative consequences such as overtraining and burnout. However, acceptance or willingness of athletes to participate is a barrier to an effective training monitoring program. Educational strategies may potentially increase adherence. Therefore, our aims are to i) assess the impact of training monitoring education on adherence to a monitoring program ii) determine the effect of the education intervention on burnout, stress, and recovery, and iii) qualitatively investigate athlete perspectives of the education and training monitoring experience. Recreational athletes (18 male/17 female age = 42.6 ± 12.0) were randomised to either a control ( n = 19) or education ( n = 16) group and completed daily training monitoring through a smartphone application over 10 weeks. Pre-post assessments using the Athlete Burnout Questionnaire, the Acute Recovery Stress Scale, and a perceived knowledge of training monitoring questionnaire, and semi-structured interviews were performed. Adherence was low, with no differences between the control group ([mean ± SD] 43.0 ± 38.8%) and the education group (45.8 ± 36.7%). There were also no differences (p .05) between the groups on the standardised inventories. There was a significant effect of time (p .001) on participant's perceived understanding of training monitoring tools (scored out of 42) at the end of the washout period (Control: 24.4 ± 6.6 Education: 28.5 ± 5.6) and post-study (Control: 32.1 ± 7.5 Education: 35.1 ± 6.0) compared to the pre-study (Control: 21.5 ± 7.3 Education: 21.9 ± 7.7). Interviews revealed participants wanted more education on modifying their training, and feedback on their data. Our findings suggest this specific educational approach was not enough to increase adherence other aspects of education and in idual feedback needs to be further explored.
Publisher: Informa UK Limited
Date: 30-01-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2018
DOI: 10.1519/JSC.0000000000002728
Abstract: 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 32(10): 2918–2924, 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 levels by position. Ninety-six elite junior soccer players were assessed between 2015 and 2017. Ninety-six elite junior soccer players (at time of match: age, 15.8 ± 0.9 years body mass, 69.1 ± 8.0 kg) were assessed during 61 games within the 2015, 2016, and 2017 season, for a total of 441 in idual match observations (4.8 ± 3.3 matches per player, range 1–13). Participants were classified by age group: under 15 (U15, n = 121, 14.7 ± 0.3 years), under 16 (U16, n = 176, 15.8 ± 0.3 years), or under 17 (U17, n = 144, 16.7 ± 0.4 years), and according to their playing position: Attacker (ATT), Defender (DEF), Mid-Fielder (MID), or Wide (WIDE). Participants wore global positioning system units during each match, where speed (m·min −1 ), acceleration/deceleration (m·s −2 ), and metabolic power (P met ) were established. A 1- to 10-minute moving average was applied to establish the intercept (c) and slope ( n ) of running intensity variables as a power law y = cx n relationship. Linear mixed models were used to examine differences in the intercept and slope between age group and player position. There were no substantial differences in peak (intercept) or decline (slope) in running intensity between playing levels. Several differences were observed in the peak running speeds (m·min −1 ), particularly peak running speeds of ATT and DEF being substantially lower than the MID. Despite variability between positions, we suggest that the magnitude of these differences would not warrant the prescription of different running intensities across positions at the elite junior level. These findings describe the peak running intensities of elite junior soccer, useful in the monitoring and prescription of training to ensure that players are prepared for the most demanding periods of competition.
Publisher: Informa UK Limited
Date: 29-09-2020
DOI: 10.1080/17461391.2019.1669718
Abstract: This study examined the relationship between dual-energy x-ray absorptiometry (DXA)-derived estimates of energy balance (EB) and changes in body composition across various seasonal phases in team sport athletes. Forty-five Australian rules footballers underwent six DXA scans across a 12-month period (off-season [OS, Week 0-13], early [PS1, Week 13-22] and late pre-season [PS2, Week 22-31] and early [IS1, Week 3-42] and late in-season [IS2, Week 42-51]). EB (kcal·day
Publisher: Human Kinetics
Date: 03-2023
Abstract: Purpose : The aim of this systematic review was to (1) determine the muscle fiber-type composition (or muscle fiber typology [MFT]) of team-sport athletes and (2) examine associations between MFT and the physical characteristics and performance tasks in team-sport athletes. Methods : Searches were conducted across numerous databases—PubMed, SPORTDiscus, MEDLINE, and Google Scholar—using consistent search terms. Studies were included if they examined the MFT of team-sport athletes. Included studies underwent critical appraisal using the McMasters University critical appraisal tool for quantitative research. Results : A total of 10 studies were included in the present review, wherein the MFT of athletes was measured from 5 different team sports (soccer, rugby union, rugby league, handball, and volleyball). There was large variability in the MFT of team-sport athletes both within (up to 27.5%) and between sports (24.0% relative difference). Male football players with a higher proportion of type II fibers had faster 10- and 30-m sprint times, achieved a greater total distance sprinting (distance at .67 m·s −1 ), and a greater peak 1-minute sprint distance. Conclusions : MFT varies considerably between athletes both within and between different team sports. The results from some studies suggest that variation in MFT is associated with high-intensity running performance in a football match, as well as 10- and 30-m sprint times. Further experimental studies should focus on how determination of the MFT of team-sport athletes could be utilized to influence talent identification, team selection, and the in idualization of training.
Publisher: Frontiers Media SA
Date: 23-12-2020
DOI: 10.3389/FSPOR.2020.608939
Abstract: 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 distance, very high-speed distance, acceleration, and acceleration load. Using raw GNSS files, 1-min moving averages were calculated for speed (m·min −1 ) and acceleration (m·s −2 ), and were multiplied by time, specifying total distance (m), and by body mass to quantify impulse (kN·s −1 ). The distribution of distance and impulse accumulated at varied intensities relative to MMs was calculated, with percentages ranging from zero to 110%. Drills were categorized as either warm-ups, skill drills, games (i.e., small-sided games), conditioning and matches. Linear mixed models determined if the distribution of intensity within each threshold (& %) varied between drill types and matches, and if the distribution within drill types varied across the season. Effects were described using standardized effect sizes (ES) and 90% confidence limits (CL). Compared to matches, a higher proportion of distance was accumulated at 50% of the MM within warm-ups and conditioning (ES range 0.86–1.14). During matches a higher proportion of distance was accumulated at 60% of MM when compared to warms ups, skill drills and conditioning (0.73–1.87). Similarly, greater proportion of distance was accumulated between 70 and 100% MM in matches compared to skill drills and warm-ups (1.05–3.93). For impulse, matches had a higher proportion between 60 and 80% of the MM compared to conditioning drills (0.91–3.23). There were no other substantial differences in the proportion of impulse between matches and drill types. When comparing phases, during competition there was a higher proportion of distance accumulated at 50% MM than general preparation (1.08). A higher proportion of distance was covered at higher intensities within matches compared to drills. The proportion of impulse was higher between 60 and 80% MM within matches compared to conditioning. Practitioners can therefore ensure athletes are not only exposed to the intensities common within competition, but also the volume accumulated is comparable, which may have positive performance outcomes, but is also extremely important in the return to play process.
Publisher: Human Kinetics
Date: 03-2016
Abstract: High levels of lean mass are important in collision-based sports for the development of strength and power, which may also assist during contact situations. While 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 determine the most effective method of quantifying changes in lean mass in rugby league athletes. Body composition of 21 professional rugby league players was assessed on 2 or 3 occasions separated by ≥6 wk, including bioelectrical impedance analysis (BIA), leanmass index (LMI), and a skinfold-based prediction equation (SkF). Dual-X-ray absorptiometry provided a criterion measure of fat-free mass (FFM). Correlation coefficients ( r ) and standard errors of the estimate (SEE) were used as measures of validity for the estimates. All 3 practical estimates exhibited strong validity for cross-sectional assessments of FFM ( r .9, P .001). The correlation between change scores was stronger for the LMI ( r = .69, SEE 1.3 kg) and the SkF method ( r = .66, SEE = 1.4 kg) than for BIA ( r = .50, SEE = 1.6 kg). The LMI is probably as accurate in predicting changes in FFM as SkF and very likely to be more appropriate than BIA. The LMI offers an adequate, practical alternative for assessing in FFM among rugby league athletes.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 13-05-2020
DOI: 10.1519/JSC.0000000000003613
Abstract: 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 36(5): 1360–1366, 2022—This study determined the distribution of distance, impulse, and accelerometer load accumulated at intensities relative to the maximal mean 1-minute peak intensity within professional rugby league and Australian football. Within 26 rugby league ( n = 24 athletes) and 18 Australian football ( n = 38 athletes) games, athletes wore global navigation satellite system devices ( n = 608 match files). One-minute maximal mean values were calculated for each athlete per game for speed (m·minP −1 P), accelerometer load (AU·minP −1 P), and acceleration (m·sP −2 P). Volumes for each parameter were calculated by multiplying by time, specifying total distance, accelerometer load, and impulse. The distribution of intensity of which these variables were performed relative to the maximal mean was calculated, with percentages ranging from 0–110%, separated into 10% thresholds. Linear mixed models determined whether the distribution of activities within each threshold varied, and positional differences. Effects were described using standardized effect sizes (ESs), and magnitude-based decisions. Across both sports, the distribution of activity (%) largely reduced the closer to the maximal mean 1-minute peak and was highest at ∼60% of the maximal mean peak. When compared with Australian football, a higher percentage of total distance was accumulated at higher intensities (70–80% and 100–110%) for rugby league (ES range = 0.82–0.87), with similar, yet larger differences for accelerometer load % (0.78–1.07) and impulse % (1.00–2.26). These findings provide information of the volume of activities performed relative to the mean maximal 1-minute peak period, which may assist in the prescription of training.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-09-2020
DOI: 10.1519/JSC.0000000000003810
Abstract: Thornton, HR, Armstrong, CR, Gamble, T, Rigby, A, Johnston, RD, and Duthie, GM. Quantifying the movement characteristics of Australian Football League Women's competition. J Strength Cond Res 36(12): 3415–3421, 2022—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 global positioning system devices during games and were summarized according to positional groups. The variance in each athlete's match loads for each round were expressed using standardized scores ( z -scores), and the change compared with the first game played was calculated and expressed as a standard deviation. Furthermore, using the raw export, moving means (1–10 minutes) of speed (m·min −1 ) and acceleration (m·s −2 ) were calculated. Following log transformation of the maximal means, intercept and slopes were calculated. Linear mixed models identified differences between positional groups for match loads, and intercept and slopes. Effects were described using standardized effect sizes (ESs) and magnitude-based decisions. There were no substantial and unclear differences between positional groups for match loads (ES range ±confidence limits = 0.10–0.80 ±0.30–4.30) and for intercept and slopes (ES range 0.04–0.44 ±0.52–2.11). Large within-athlete variation in match demands between rounds was observed ( z -score up to −1.8 SD for distance), and the maximal means for speed and acceleration demonstrate the extensive physical demands of AFLW competition. These data describe the intense and variable physical demands of AFLW competition, and further provide novel information regarding the maximal mean intensities and intercept and slopes, which should assist practitioners in planning and prescribing training in preparation for competition.
Publisher: Human Kinetics
Date: 04-2019
Abstract: Purpose : To establish the interunit reliability of a range of global positioning system (GPS)-derived movement indicators, to determine the variation between manufacturers, and to investigate the difference between software-derived and raw data. Methods : A range of movement variables were obtained from 27 GPS units from 3 manufacturers (GPSports EVO, 10 Hz, n = 10 STATSports Apex, 10 Hz, n = 10 and Catapult S5, 10 Hz, n = 7) that measured the same team-sport simulation session while positioned on a sled. The interunit reliability was determined using the coefficient of variation (%) and 90% confidence limits, whereas between-manufacturers comparisons and comparisons of software versus raw processed data were established using standardized effect sizes and 90% confidence limits. Results : The interunit reliability for both software and raw processed data ranged from good to poor (coefficient of variation = 0.2% ±1.5% to 78.2% ±1.5%), with distance, speed, and maximal speed exhibiting the best reliability. There were substantial differences between manufacturers, particularly for threshold-based acceleration and deceleration variables (effect sizes ±90% confidence limits: −2.0 ±0.1 to 1.9 ±0.1), and there were substantial differences between data-processing methods for a range of movement indicators. Conclusions : The interunit reliability of most movement indicators was deemed as good regardless of processing method, suggesting that practitioners can have confidence within systems. Standardized data-processing methods are recommended, due to the large differences between data outputs from various manufacturer-derived software.
Publisher: Informa UK Limited
Date: 09-10-2018
Publisher: Human Kinetics
Date: 09-2015
Abstract: Rugby league involves frequent periods of high-intensity running including acceleration and deceleration efforts, often occurring at low speeds. To quantify the energetic cost of running and acceleration efforts during rugby league competition to aid in prescription and monitoring of training. Global positioning system (GPS) data were collected from 37 professional rugby league players across 2 seasons. Peak values for relative distance, average acceleration/deceleration, and metabolic power (P met ) were calculated for 10 different moving-average durations (1–10 min) for each position. A mixed-effects model was used to assess the effect of position for each duration, and in idual comparisons were made using a magnitude-based-inference network. There were almost certainly large differences in relative distance and P met between the 10-min window and all moving averages min in duration (ES = 1.21–1.88). Fullbacks, halves, and hookers covered greater relative distances than outside backs, edge forwards, and middle forwards for moving averages lasting 2–10 min. Acceleration/deceleration demands were greatest in hookers and halves compared with fullbacks, middle forwards, and outside backs. P met was greatest in hookers, halves, and fullbacks compared with middle forwards and outside backs. Competition running intensities varied by both position and moving-average duration. Hookers exhibited the greatest P met of all positions, due to high involvement in both attack and defense. Fullbacks also reached high P met , possibly due to a greater absolute volume of running. This study provides coaches with match data that can be used for the prescription and monitoring of specific training drills.
Publisher: Human Kinetics
Date: 02-2017
Abstract: To investigate the influence of daily and exponentially weighted moving training loads on subsequent nighttime sleep. Sleep of 14 professional rugby league athletes competing in the National Rugby League was recorded using wristwatch actigraphy. Physical demands were quantified using GPS technology, including total distance, high-speed distance, acceleration/deceleration load (SumAccDec AU), and session rating of perceived exertion (AU). Linear mixed models determined effects of acute (daily) and subacute (3- and 7-d) exponentially weighted moving averages (EWMA) on sleep. Higher daily SumAccDec was associated with increased sleep efficiency (effect-size correlation ES = 0.15 ±0.09) and sleep duration (ES = 0.12 ±0.09). Greater 3-d EWMA SumAccDec was associated with increased sleep efficiency (ES = 0.14 ±0.09) and an earlier bedtime (ES = 0.14 ±0.09). An increase in 7-d EWMA SumAccDec was associated with heightened sleep efficiency (ES = 0.15 ±0.09) and earlier bedtimes (ES = 0.15 ±0.09). The direction of the associations between training loads and sleep varied, but the strongest relationships showed that higher training loads increased various measures of sleep. Practitioners should be aware of the increased requirement for sleep during intensified training periods, using this information in the planning and implementation of training and in idualized recovery modalities.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.JSAMS.2016.11.009
Abstract: To establish the position and duration-specific running demands of Australian Football (AF) competition for the prescription and monitoring of specific training drills. An observational time-motion analysis was performed on 40 professional AF players during 30 games throughout the 2014-15 competitive seasons. Player movements were collected and peak values were calculated for moving averages of between 1-10min in duration for relative distance (mmin Relative distance was likely greater for midfielders (MID), and mobile forwards (MF) compared to tall backs (TB) across all moving average durations assessed, with MF peaking at 223±35mmin The present study demonstrated that the peak running intensities of AF are well above previously reported peak intensities when considering the distance-based running requirements of match-play. Whilst the acceleration-based metric was unable to detect large differences between positions, it is important to note their contribution to the overall competition demands. This study presents a useful framework for the prescription and monitoring of drills specific to AF competition requirements.
Publisher: Frontiers Media SA
Date: 20-12-2018
No related grants have been discovered for Heidi Compton.