The influence of lightweight wearable resistance on whole body coordination during sprint acceleration among Australian Rules football players.

Rapid acceleration is an important quality for field-based sport athletes. Technical factors contribute to acceleration and these can be deliberately influenced by coaches through implementation of constraints, which afford particular coordinative states or induce variability generally. Lightweight wearable resistance is an emerging training tool, which can act as a constraint on acceleration.

A reduced exposure heated tobacco product was introduced then abruptly taken off United States shelves: results from a tobacco harm reduction natural experiment.

Background: A heated tobacco product (HTP) authorized for purchase in the United States by the Food and Drug Administration as a reduced harm product was removed from the market after about 2 years of sales. Adults who used the HTP were surveyed to determine the impact of the introduction and removal of the HTP on past and current tobacco behaviors.

Methods: Adults who were using the HTP before its United States market removal (n = 502) completed a cross-sectional online survey to determine their tobacco use behaviors at three timepoints: prior to HTP initiation, just before HTP market removal, and at the time of the survey which was administered approximately 10 months post-removal.

Exploration of collective tactical variables in elite netball: An analysis of team and sub-group positioning behaviours.

Collective tactical behaviours are aspects of player interactions that are particularly important in netball, due to its unique restrictions on player movement (players unable to move when in possession of the ball and positional spatial restrictions). The aim of this study was to explore variables representing collective tactical behaviours in netball. A local positioning system provided player positions of one team throughout seven elite-level netball matches.

Challenges and considerations in determining the quality of electronic performance & tracking systems for team sports.

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. Consequently the quality of such systems is of importance to a range of stakeholders.

Understanding the effects of ball orientation in Rugby Union place kicking: the preferences of international kickers and the kinematics of the foot-ball impact.

Rugby Union place kicking is influential to match outcome. Previous research has analysed kicker motion prior to ball contact in detail, but ball orientation and the impact phase are typically ignored. This study aims to firstly identify the ball orientations used by international place kickers, and secondly to experimentally analyse the foot-ball interaction in trained kickers using different ball orientations.

Chronic restraint stress increases sensitivity to punishment during cocaine self-administration via a dopamine D-like receptor-mediated mechanism in prelimbic medial prefrontal cortex.

We recently reported that male rats displayed less sensitivity to punishment during cocaine self-administration compared to females. Moreover, daily restraint stress increased sensitivity to punishment in males, while having no effect in females. The purpose of the present study was to extend these findings by determining whether chronic stress-induced dopamine release in prelimbic medial prefrontal cortex mediates the effect of stress on punished cocaine self-administration.

Kick proficiency and skill adaptability increase from an Australian football small-sided game intervention.

This investigation is the first to explore the effect of a 4 week small-sided game (SSG) and traditional training intervention on player kick proficiency and player adaptability in Australian football. Twenty-two amateur Australian football players (mean ± SD; age 22.3 ± 2.

Sex-dependent effects of chronic stress on punished cocaine self-administration and cue-induced relapse to cocaine seeking.

We tested the effects of chronic stress on cocaine relapse after drug-reinforced responding was suppressed by punishment, an animal model of human relapse after self-imposed abstinence due to the negative consequences of drug use. Male rats displayed greater resistance to punishment than females, but daily stress decreased this resistance. Only female rats with a history of chronic stress displayed increased responding for cocaine cues from abstinence Day 1 to Day 8.

Prelimbic medial prefrontal cortex has bidirectional control over the expression of behavioral sensitization to 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) depending on the context of drug administration.

Behavioral sensitization to MDMA is observed in the vast majority of rats if tested in the same environment in which previous MDMA exposure occurred, but not if tested in a novel, unpaired context. Previous studies have revealed a critical role for the prelimbic region of medial prefrontal cortex (PL) in the expression of sensitization to MDMA, but these studies assessed sensitization only in MDMA-paired environments. Given that PL activity can both facilitate and suppress behavior depending on context, we tested the hypothesis that PL has bidirectional control over the expression of locomotor sensitization to MDMA depending on the context of drug administration.

Applying common filtering processes to Global Navigation Satellite System-derived acceleration during team sport locomotion.

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 = 13). Raw GNSS data were exported from respective proprietary software and a 1 Hz, 4th-order Butterworth filter applied, with differences in speed and acceleration calculated between manufacturers.

The introduction of the six-again rule has increased acceleration intensity across all positions in the National Rugby League competition.

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 who competed in 56 matches across the 2019 to 2021 NRL seasons. Maximal mean speed (m·min) and acceleration (m·s) were established across a 10 s to 10-min duration via raw GNSS files, with subsequent intercept (mean estimates) and slope values determined via power law analysis.

Prediction of 2000-m on-water rowing performance with measures derived from instrumented boats.

Purpose: Rowing instrumentation systems provide measures of stroke power, stroke rate, and boat velocity during rowing races, but how well these measures predict race performance has not been reported previously.

Methods: Data were collected per stroke from 45 2000-m races using Peach PowerLine and OptimEye S5 GPS units. The boat classes assessed were nine male singles, eight female singles, three male pairs, and six female pairs.

Concurrent Validity of Power From Three On-Water Rowing Instrumentation Systems and a Concept2 Ergometer.

Instrumentation systems are increasingly used in rowing to measure training intensity and performance but have not been validated for measures of power. In this study, the concurrent validity of Peach PowerLine (six units), Nielsen-Kellerman EmPower (five units), Weba OarPowerMeter (three units), Concept2 model D ergometer (one unit), and a custom-built reference instrumentation system (Reference System; one unit) were investigated. Eight female and seven male rowers [age, 21 ± 2.

Dopamine D-like receptors in prelimbic, but not infralimbic, medial prefrontal cortex contribute to chronic stress-induced increases in cue-induced relapse to palatable food seeking during forced abstinence.

Chronic stress exposure causes increased vulnerability to future relapse-like behavior in male, but not female, rats with a history of palatable food self-administration. These effects are mediated by dopamine D-like receptors, but the anatomical location of chronic stress' dopaminergic mechanism is not known. Thus, male rats were trained to respond for palatable food pellets in daily sessions.

Relationships between measures of boat acceleration and performance in rowing, with and without controlling for stroke rate and power output.

Purpose: Boat acceleration profiles provide a valuable feedback tool by reflecting both rower technique and force application. Relationships between measures of boat acceleration and velocity to inform interpretation of boat acceleration profiles in rowing were investigated here.

Methods: Thirteen male singles, nine female singles, eight male pairs, and seven female pairs participated (national and international level, age 18-27 y).

The Quantification of Acceleration Events in Elite Team Sport: a Systematic Review.

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.

Corrigendum: Technical Determinants of On-Water Rowing Performance.

[This corrects the article DOI: 10.3389/fspor.2020.

Classification of Australian football kick types in-situation via ankle-mounted inertial measurement units.

The utility of inertial measurement units (IMUs) for sporting skill and performance analysis during training and competition is advantageous for enhancing the objectivity of athlete monitoring. This study aimed to classify Australian Rules football (AF) kick types in an applied environment using ankle-mounted IMUs. IMUs and video capture of a controlled protocol, including four kick types at varying distances, were recorded during a single testing session with female AF athletes (n = 20).

Future Directions and Considerations for Talent Identification in Australian Football.

As the focus on the elite Australian Football League competition becomes greater so too does the demand for success. Clubs are heavily scrutinized for their draft selections and as such are taking more interest in the younger levels of competition in an attempt to identify and monitor talent. Based on contemporary talent identification knowledge, this review examines the current talent identification process in Australian football, with a focus on areas to potentially improve or inform future developments.

Technical Determinants of On-Water Rowing Performance.

Research establishing relationships between measures of rowing technique and velocity is limited. In this study, measures of technique and their effect on rowing velocity were investigated. Ten male singles, eight female singles, three male pairs, and six female pairs participated.

Biomechanics of accurate and inaccurate goal-kicking in Australian football: Group-based analysis.

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-dimensional kinematics collected using the Xsens inertial measurement system (Xsens Technologies B.

Sex-dependent effects of chronic stress on reinstatement of palatable food seeking and involvement of dopamine D-like receptors.

Recent work in our lab has shown that chronic stress exposure causes sex-dependent changes in subsequent relapse-like behavior in rats with a history of palatable food self-administration. Although these effects are mediated by dopamine D-like receptors in male rats, such dopaminergic mechanisms have not been investigated in female animals. Thus, male and female rats were trained to respond for highly palatable food reinforcers in daily sessions.

Criterion Validity of Catapult ClearSky T6 Local Positioning System for Measuring Inter-Unit Distance.

The validity of a local positioning system (LPS) to measure inter-unit distance was investigated during a team sport movement circuit. Eight recreationally active, female indoor team-sport players completed a circuit, comprising seven types of movements (walk, jog, jump, sprint, 45° change of direction and shuffle), on an indoor court. Participants wore a receiver tag (ClearSky T6, Catapult Sports) and seven reflective markers, to allow for a comparison with the reference system (©Vicon Motion Systems, Oxford Metrics, UK).