Quantifying the training demands of a highly trained male youth basketball players by year, term and position.

This study describes the training demands of highly trained male youth basketball players, based on training year, term and playing position. Data was collected from 41 male youth basketballers over two seasons from all on-court coach-led training sessions utilising an LPS. Linear mixed-models and pairwise comparisons were used to analyse by training year (Y1, Y2 and Y3), term (T1, T2, T3 and T4) and playing position (Backcourt, Frontcourt). Results showed no differences in external load metrics between training years. Significant differences existed between training terms, with total distance greater in both T3 and T4 than T1 and 2 (p < 0.03). Total PlayerLoad was significantly greater in T4 than T1 (p < 0.001) and T3 (p = 0.004). Distance/min was greater in T2, T3 and T4 than T1 (p < 0.01). PlayerLoad/min was higher in T4 than T1 and T2 (p < 0.01). Backcourt players showed significantly greater distance/min (p = 0.011), PlayerLoad/min (p = 0.011) and deceleration counts (p < 0.001). Overall, limited year-on-year change existed in external training load metrics (p > 0.05), though volume (p < 0.001) and intensity (p < 0.001) differed between terms. Backcourt players completed higher intensities (p = 0.011) than Frontcourt players. This study provides a description of external loads of training in highly trained youth basketball players assisting coaches and performance practitioners to better understand physical demands within youth basketball development pathways.

Technical Note: Assessing GPS Sensor Accuracy Using Real-Time Kinematic Device for Livestock Tracking.

The technical aspects of GPS sensors have been improved substantially over the years, making them valuable and popular tools for livestock tracking. Using GPS sensors allows producers and researchers to locate grazing livestock, monitor their behavior and distribution, and gather referencing information about the health status of the animals and pastures. However, interpreting the behavior of grazing livestock, such as cattle, from GPS data can be difficult due to positioning inaccuracies. Without knowing the positioning accuracy range of GPS sensors, achieving high-level confidence in determining grazing densities and identifying abnormal livestock movement patterns is challenging. In this study, the positioning accuracy of three different types of commercial GPS sensors was assessed using a survey-grade real-time kinematics (RTK) device. We outlined the procedures, essential equations and compared the recorded locations from the GPS sensors with reference locations collected from the RTK device. The results demonstrated statistically significant differences (p < 0.05) in positioning accuracy between different types of GPS sensors. The circular error probable (CEP) at 95% probability levels (CEP95) of the three sensors ranged from 2.46 m to 11.06 m. This accuracy varied among individual sensors within the same brand and across different brands, which underscores the importance of evaluating positioning accuracy of GPS sensors in livestock tracking. This study provides significant insights for animal scientists, ecologists, and livestock producers engaged in GPS sensor-related research and practices.

Surfing Time-Motion Characteristics Possible to Gain Using Global Navigation Satellite Systems: A Systematic Review.

The popularity of surfing has increased exponentially, reaching its recent debut in the Olympic Games. However, surfing suffers from a relative immature technological market, while in other sports some technologies such as global navigation satellite systems (GNSSs) have become an essential work material for strength and conditioning and head coaches. This article aims to systematically review surfers' time-motion demands based on GNSSs. A systematic review of relevant articles was carried out using five main databases (PubMed, ProQuest Central, SCOPUS, SPORTDiscus, and FECYT (Web of Sciences, CCC, CIDW, KJD, MEDLINE, RSCI, and SCIELO)) until 23 March 2024. From the 238 studies initially found, 9 were included in the qualitative synthesis. In these, GNSS devices were employed with male (n = 143) and female (n = 28) surfers from different levels during competition and training situations. The studies show that the intermittent nature of the sport is evident, with substantial periods spent paddling and waiting punctuated by relatively brief high-intensity efforts when riding waves at high speeds. Notable differences emerged between competition and training demands, suggesting potential mismatches in how athletes currently prepare compared to event requirements. These novel insights allow quantifying surfing's harsh physiological requirements and could guide conditioning practices to better meet the sport's unique characteristics across populations. Therefore, training should emulate the lengthy aerobic capabilities needed for the paddling volumes observed, while also targeting the anaerobic systems to meet the repeated high-intensity surf riding efforts. However, inconsistencies in methods and reporting practices limit direct comparisons and comprehensive profiling of the sport's physical characteristics.

Internal and External Load Profile during Beach Invasion Sports Match-Play by Electronic Performance and Tracking Systems: A Systematic Review.

Beach variants of popular sports like soccer and handball have grown in participation over the last decade. However, the characterization of the workload demands in beach sports remains limited compared to their indoor equivalents. This systematic review aimed to: (1) characterize internal and external loads during beach invasion sports match-play; (2) identify technologies and metrics used for monitoring; (3) compare the demands of indoor sports; and (4) explore differences by competition level, age, sex, and beach sport. Fifteen studies ultimately met the inclusion criteria. The locomotive volumes averaged 929 ± 269 m (average) and 16.5 ± 3.3 km/h (peak) alongside 368 ± 103 accelerations and 8 ± 4 jumps per session. The impacts approached 700 per session. The heart rates reached 166-192 beats per minute (maximal) eliciting 60-95% intensity. The player load was 12.5 ± 2.9 to 125 ± 30 units. Males showed 10-15% higher external but equivalent internal loads versus females. Earlier studies relied solely on a time-motion analysis, while recent works integrate electronic performance and tracking systems, enabling a more holistic quantification. However, substantial metric intensity zone variability persists. Beach sports entail intermittent high-intensity activity with a lower-intensity recovery. Unstable surface likely explains the heightened internal strain despite moderately lower running volumes than indoor sports. The continued integration of technology together with the standardization of workload intensity zones is needed to inform a beach-specific training prescription.

On-field rehabilitation in football: current practice and perceptions. A survey of the English Premier League and Football League.

INTRODUCTION: Return to play related research is increasing rapidly, with two recent competency-based frameworks offering conceptualised support for on-field rehabilitation (OFR) decision-making. It is still unknown, however, who is responsible for OFR and how they typically select, monitor, and progress OFR processes. AIMS: The purpose of this study was to investigate current OFR practice within English professional football to support practitioners with decision-making and highlight opportunities for future research related to the design, monitoring, and progression of OFR. METHODS: Sixty-nine practitioners responsible for the design and implementation of OFR at 69 clubs (75% of the English Premier League and Football League) responded to a survey containing 30 questions (14 open and 16 closed). RESULTS: The main findings were that therapists (physiotherapists/sports therapists) have the largest influence on OFR, followed by physical performance coaches (sports scientists/strength and conditioning coaches), technical coaches and medical doctors. There was more agreement for the ordering of specific OFR drills earlier in the process when activities are easier to control. The most frequently reported objective monitoring tool was global positioning systems (GPS), with functional/clinical experience/expertise remaining subjectively vital. GPS outputs (e.g., sprint metrics and accelerations/decelerations) were most used for between session decision-making, with verbal communication being key for within session decision-making. CONCLUSION: Future research should use evidence of current practice, such as drill design and monitoring techniques, to explore drill-level analysis and give practitioners greater insights into which stage of current OFR frameworks specific drills fall, and how they might be more objectively progressed/regressed.

Global positioning system-based food environment exposures, diet-related, and cardiometabolic health outcomes: a systematic review and research agenda.

BACKGROUND: Geographic access to food may affect dietary choices and health outcomes, but the strength and direction of associations may depend on the operationalization of exposure measures. We aimed to systematically review the literature on up-to-date evidence on the association between food environment exposures based on Global Positioning System (GPS) and diet-related and cardiometabolic health outcomes. METHODS: The databases PubMed, Embase.com, APA PsycInfo (via Ebsco), Cinahl (via Ebsco), the Web of Science Core Collection, Scopus, and the International Bibliography of the Social Sciences (via ProQuest) were searched from inception to October 31, 2022. We included studies that measured the activity space through GPS tracking data to identify exposure to food outlets and assessed associations with either diet-related or cardiometabolic health outcomes. Quality assessment was evaluated using the criteria from a modified version of the Newcastle-Ottawa Scale (NOS) for cross-sectional studies. We additionally used four items from a quality assessment tool to specifically assess the quality of GPS measurements. RESULTS: Of 2949 studies retrieved, 14 studies fulfilled our inclusion criteria. They were heterogeneous and represent inconsistent evidence. Yet, three studies found associations between food outlets and food purchases, for example, more exposure to junk food outlets was associated with higher odds of junk food purchases. Two studies found associations between greater exposure to fast food outlets and higher fast food consumption and out of three studies that investigated food environment in relation to metabolic outcomes, two studies found that higher exposure to an unhealthy food environment was associated with higher odds of being overweight. CONCLUSIONS: The current and limited evidence base does not provide strong evidence for consistent associations of GPS-based exposures of the food environment with diet-related and cardiometabolic health outcomes.

Comparison of weekly training load and acute:chronic workload ratio methods to estimate change in training load in running.

CONTEXT: Before examining the impact of training load on injury risk in runners, it is important to gain insight in the differences between methods that are used to measure change in training load. OBJECTIVE: To investigate differences between four methods to calculate change in training load: (1) weekly training load; (2) acute:chronic workload ratio (ACWR), coupled rolling average (RA); (3) ACWR, uncoupled RA; (4) ACWR, exponentially weighted moving averages (EWMA). DESIGN: Descriptive epidemiology study. SETTING: This study is part of a randomized-controlled trial on running injury prevention among recreational runners. Runners received a baseline questionnaire and a request to share GPS training data. PARTICIPANTS: Runners who registered for running events (distances 10-42.195 kilometers) in the Netherlands. MAIN OUTCOME MEASURES: Primary outcome measure was the predefined significant increase in training load (weekly training loads ≥30% progression and ACWRs ≥1.5), based on training distance. Proportional Venn diagrams visualized the differences between the methods. RESULTS: 430 participants (73.3% men; age 44.3 years) shared their GPS training data with in total 22,839 training sessions. For the weekly training load, coupled RA, uncoupled RA, and EWMA method, respectively 33.4% (95% CI 32.8-34.0), 16.2% (95% CI 15.7-16.6), 25.8% (95% CI 25.3-26.4), and 18.9% (95% CI 18.4-19.4) of the training sessions were classified as significant increase in training load. Of the training sessions with significant increase in training load, 43.0% expressed in the weekly training load method showed a difference with the coupled RA and EWMA method. Training sessions with significant increase in training load based on the coupled RA method showed 100% overlap with the uncoupled RA and EWMA method. CONCLUSIONS: The difference in change in training load measured by weekly training load and ACWR methods was high. To validate an appropriate measure of change in training load in runners, future research on the association between training loads and RRI risk is needed.

Tracking devices and physical performance analysis in team sports: a comprehensive framework for research-trends and future directions.

Background: Tracking devices, such as global (GPS) and local (LPS) positioning systems, combined with physiological measurements, have become reliable tools to characterize movement patterns, assessing the external load (EL), internal load (IL), fatigue, and performance of athletes in team sports. This scoping review aims to provide a comprehensive understanding of the applicability of tracking systems in physical performance analysis within team sports and the wellbeing of athletes based on research strategies and combined variables. Methods: A systematic search was conducted in PubMed, Web of Knowledge, and Scopus databases according to PRISMA guidelines. The 79 studies that were reviewed met the following criteria: (1) contained relevant data regarding elite athletes' performance; (2) athletes' EL and IL; (3) were written in the English language; (4) were related only to team sports. Results: The findings indicate that tracking technology has been engaged in several research areas, including performance analysis, training vs. match load management, injuries, and nutrition, through characterization and correlational studies. Metrics, primarily focused on kinematic and mechanical EL aspects, have been employed in combination with IL data to analyze the performance of athletes. However, the lack of an integrative model for the analysis and integration of EL and IL metrics within each team sport suggests an interesting direction for further research. Conclusion: There is a need for coherence between the methods and the research goals on performance analysis. The development of a framework that guides experimental studies is highly recommended, particularly on manipulating metrics analyzed between training and match sessions, injury prevention, and nutrition. This will lead to the development of the most applied sports science research to improve the preparation and decision-making of athletes based on reliable data. Systematic Review Registration: https://inplasy.com/?s=2022120039, identifier 2022120039.

Profiling Professional Rugby Union Activity After Peak Match Periods.

The aim of this investigation was to quantify professional rugby union player activity profiles after the most intense (peak) passages of matches. Movement data were collected from 30 elite and 30 subelite professional rugby union athletes across respective competitive seasons. Accelerometer-derived PlayerLoad and global navigation satellite system-derived measures of mean speed and metabolic power were analyzed using a rolling-average method to identify the most intense 5- to 600-second passages (ie, worst-case scenarios) within matches. Player activity profiles immediately post their peak 5- to 600-second match intensity were identified using 5 epoch duration-matched intervals. Mean speed, metabolic power, and PlayerLoad declined sharply (∼29%-86%) after the most intense 5 to 600 seconds of matches. Following the most intense periods of rugby matches, exercise intensity declined below the average match-half intensity 81% of the time and seldom returned to or exceeded it, likely due to a host of individual physical and physiological characteristics, transient and/or accumulative fatigue, contextual factors, and pacing strategies. Typically, player exercise intensities after the most intense passages of matches were similar between match halves, positional groups, and levels of rugby competition. Accurate identification of the peak exercise intensities of matches and movement thereafter using novel methodologies has improved the limited understanding of professional rugby union player activity profiles following the worst-case scenarios of matches. Findings of the present study may inform match-representative training prescription, monitoring, and tactical match decisions (eg, substitutions and positional changes).

The influence of fixture congestion on physical performance response to U23 soccer match-play.

This study sought to examine differences in measures of intense periods of physical performance during competitive match-play, between one-match (1 match weeks) and two-match microcycles (2 match week). 1, 3 and 5 min "peak" and mean averages for total distance (TD), high-speed running (HSR) and metabolic power (MP) were analysed for each 15 min period of match-play. Linear mixed models were employed to examine the differences in dependent variables for each method of measurement between the 1 and 2 game microcycles. No differences were reported for "peak" values for all epoch lengths, however, results revealed significantly reduced "average" values, during periods of fixture congestion, for 1, 3 and 5 min epochs for average TD, and 3 min epochs for average HSR towards the end of the match (75-90 min split). There was, however, a trend for the opposite response to occur in the 60-75-min period. The current data suggests that players potentially display altered pacing strategies during periods of fixture congestion, with these observed responses being dependent on sampling method and epoch length.

Moving beyond velocity derivatives; using global positioning system data to extract sequential movement patterns at different levels of rugby league match-play.

This study aims to (a) quantify the movement patterns during rugby league match-play and (b) identify if differences exist by levels of competition within the movement patterns and units through the sequential movement pattern (SMP) algorithm. Global Positioning System data were analysed from three competition levels; four Super League regular (regular-SL), three Super League (semi-)Finals (final-SL) and four international rugby league (international) matches. The SMP framework extracted movement pattern data for each athlete within the dataset. Between competition levels, differences were analysed using linear discriminant analysis (LDA). Movement patterns were decomposed into their composite movement units; then Kruskal-Wallis rank-sum and Dunn post-hoc were used to show differences. The SMP algorithm found 121 movement patterns comprised mainly of "walk" and "jog" based movement units. The LDA had an accuracy score of 0.81, showing good separation between competition levels. Linear discriminant 1 and 2 explained 86% and 14% of the variance. The Kruskal-Wallis found differences between competition levels for 9 of 17 movement units. Differences were primarily present between regular-SL and international with other combinations showing less differences. Movement units which showed significant differences between competition levels were mainly composed of low velocities with mixed acceleration and turning angles. The SMP algorithm found 121 movement patterns across all levels of rugby league match-play, of which, 9 were found to show significant differences between competition levels. Of these nine, all showed significant differences present between international and domestic, whereas only four found differences present within the domestic levels. This study shows the SMP algorithm can be used to differentiate between levels of rugby league and that higher levels of competition may have greater velocity demands.Highlights This study shows that movement patterns and movement units can be used to investigate team sports through the application of the SMP frameworkOne hundred and twenty-one movement patterns were found to be present within rugby league match-play, with the walk- and jog-based movement units most prevalent. No movement pattern was unique to a single competition level.Further analysis revealed that the majority of movement units analysed had significant differences between international and domestic rugby league, whereas only four movement units (i.e. f,m,n,q) had significant differences within the two domestic rugby league levels.International rugby league had higher occurrences of the movement patterns consisting of higher velocity movement units (ie. T,S,y). This suggests that international rugby league players may need greater high velocity exposure in training.

The association between objectively measured exposure to tobacco outlets and smoking cognitions: a study among non-smoking adolescents in four Dutch cities.

AIMS: Exposure to tobacco products and advertising at the point of sale may be associated with pro-smoking cognitions. However, previous studies on this topic measured exposure based on self-report and did not include European countries. The aim of this study was to assess the association between objectively measured exposure to tobacco outlets and non-smoking adolescents' smoking attitudes, beliefs and norms. DESIGN: This cross-sectional study combined survey data with Global Positioning Systems data using geographic information system. SETTING: The four Dutch cities of Amsterdam, Eindhoven, Haarlem and Zwolle. PARTICIPANTS: We retrieved data of 308 13 to 17-year-old non-smoking adolescents, mainly girls (61%), adolescents attending pre-university secondary education (71%) and without smoking friends (58%). MEASUREMENTS: Exposure was measured with a smartphone app registering for 2 weeks how often participants were within 10 m of a tobacco outlet. We distinguished between outlets without visible tobacco promotion (i.e. supermarkets), with only internal visibility and with both internal and external visibility. Participants' reported smoking cognitions were dichotomised into pro-smoking or anti-smoking. We applied multi-level logistic regression analyses and adjusted for age, sex, educational level and smoking friends. FINDINGS: On average, adolescents were exposed to 1.18 (SD = 1.23) tobacco outlets per day. Higher exposure to tobacco outlets was associated with higher odds of pro-smoking injunctive norm ( OR = 1.35, 95% CI = 1.04-1.75). Associations with attitude (OR = 1.12, 95% CI = 0.91-1.38), social beliefs (OR = 1.15, 95% CI = 0.93-1.43), health beliefs (OR = 1.18, 95% CI = 0.97-1.44) and descriptive norm (OR = 1.15, 95% CI = 0.91-1.44) were also positive, but non-significant. Overall, associations were strongest for outlets with internal visibility, for instance, for injunctive norm (OR = 1.37, 95% CI = 1.03-1.81). CONCLUSIONS: Global Positioning Systems-measured exposure to tobacco outlets was associated with pro-smoking cognitions among non-smoking adolescents in the Netherlands.

Using principal component analysis to investigate pacing strategies in elite international canoe kayak sprint races.

The aim of this research was to use principal component analysis (PCA) to investigate the current pacing strategies of elite canoe kayak sprint athletes and to determine if there are differences in pacing patterns between medallists and non-medallists at major international competitions. Velocity data collected using global positioning systems (GPS) from all a-finals of major international competitions in 2016-2017 (including canoe and kayak, single and crew boat, and male and female) were downloaded from the International Canoe Federation's website. Data were normalised by the average velocity within each race and organised by race distance. In total 10, 14 and 16 races were analysed, and they followed all-out, positive, and 'seahorse-shaped' pacing strategies for the 200 m, 500 m, and 1000 m events, respectively. Normalised velocity PC1 (p = 0.039, ES = -0.44) and PC2 scores (p < 0.001, ES = -0.73) for 1000 m races were significantly different between medallists and non-medallists; however, significant differences between PCs were not found between groups in shorter race distances (i.e. 200 m and 500 m). Data collected using GPS provide information that can be used to better prepare athletes for canoe kayak sprint races lasting between 30 s and 240 s in duration.

Individual and situational factors affecting the movement characteristics and internal responses to Touch match-play during an international tournament.

PURPOSE: To examine the influence of individual and situational factors on the movement characteristics and internal responses of players to an international Touch tournament. METHODS: Using 47 International Touch players (25 men and 22 women), the associations between the movement characteristics and internal responses with individual (sprint, glycolytic test, Yo-Yo intermittent recovery test level 1 [Yo-Yo IR1], jump performance and well-being) and situational (sex, squad, position, competition day, points scored/conceded, result, and opposition rank) factors were examined using linear mixed modelling. RESULTS: Yo-Yo IR1 distance was associated with all movement characteristics and internal responses (r = -0.29 to 0.37), whilst sprint and glycolytic times only influenced mean heart rate (HRmean) (r = 0.15) and high-speed distance (r = 0.10), respectively. Sex influenced high-speed distance (r = -0.41), whilst squad was associated with playing time and HRmean (r = -0.10-0.33). Other associations included: playing position with all movement characteristics (r = -0.67-0.81); points conceded with relative distance (r = -0.14); winning with high metabolic power and session RPE (r = -0.07-0.09), and opposition rank with HRmean and RPE (r = 0.11-0.35). CONCLUSIONS: Individual and situational factors can influence the movement characteristics and internal responses to Touch and should be considered when developing the characteristics of players and interpreting responses to match-play.

Comparison among U-17, U-20, and Professional Female Soccer in the GPS Profiles during Brazilian Championships.

The purpose of this study was to compare and characterize the physical demand of official matches among under-17 (U-17), under-20 (U-20), and professional (Pro) female soccer players. All matches were from the U-17, U-20, and Pro National Brazilian Championships. Fourteen Pro matches, nine U-20 matches, and four U-17 matches were analyzed. The external load was measured by the global positioning system (GPS) and the internal workload was assessed by the ratings of perceived exertion (RPE) multiplied by the duration of the match. The activity profiles measured were total distance covered (km), total sprint distance (m) (speed > 18 km·h-1), number of accelerations and decelerations (between 1 and 2 m·s-2 and >3 m·s-2), and top speed (km·h-1). For the analysis, we standardized all the metrics (except the top speed) by the time (in minutes) played. The Pro group presented higher sprint distances, number of accelerations and decelerations, and top speeds, compared to U-20 and U-17. There was no difference in the total distance among groups, and there was no difference in any GPS metrics between U-20 and U-17. The RPE was higher in Pro and U-17, compared to U-20; however, the workload-RPE was higher in Pro, compared to both U-17 and U-20 groups. These findings provide important information for the evolution of physical performance according to age categories in elite female soccer players.

Effects of a small-sided games training program in youth male soccer players: variations of the locomotor profile while interacting with baseline level and with the accumulated load.

PURPOSE: This study aimed to (1) analyze the impact of a small-sided game training program in the locomotor profile of youth male soccer players (while interacting with the baseline level - higher and lower level); and (2) test the relationships between variation in locomotor profile and the accumulated demands in 3v3, 5v5 and match over the period of observation. METHODS: The cohort lasted 3-weeks. Twenty under-17 male amateur soccer players (16.8 ± 0.41 years; experience: 6.35 ± 0.67 years) were assessed twice for their final velocity at 30-15 intermittent fitness test (VIFT), peak speed at 30-m sprint test (PSS) and anaerobic speed reserve (ASR). The PSS was estimated using a Global Positioning System, while the VIFT was estimated using the maximum level attained by the players during the test. Based on the baseline levels, the scores were standardized using the Z-score. The total score of athleticism (TSA) was calculated per player to organize the players into two groups: lower TSA and higher TSA. Over the three weeks of observation, the small-sided games of 3v3 and 5v5 and match demands were monitored using polar team pro. The heart rate responses (mean and peak), distance covered (overall and split by speed thresholds), and peak speed in these games were obtained and summed over the weeks. The repeated measures ANCOVA tested the variations (time) of the locomotor profile of players while considering the baseline as covariable and the group as a factor. The Pearson-product correlation test analyzed the relationships between variations in locomotor profile (Δ, post-baseline) and the accumulated demands in 3v3, 5v5, and match. RESULTS: Between-groups analysis (lower TSA vs. higher TSA) revealed no significant differences on VIFT (p = 0.915), PSS (p = 0.269), ASR (p = 0.258) and TSA score (p = 0.138). Within-group (baseline vs. post-observation) analysis revealed significant difference on VIFT (p < 0.001), PSS (p = 0.008), while no significant differences were found on ASR (p = 0.949) and TSA score (p = 0.619). Significant correlations were found between ΔPSS and match total distance (r = 0.444; p = 0.050), match Z2 (r = 0.481; p = 0.032) and match Z3 (r = 0.454; p = 0.044). Significant correlations were found between ΔTSA and match total distance (r = 0.457; p = 0.043), match Z1 (r = 0.451; p = 0.046), match Z2 (r = 0.500; p = 0.025) and match Z3 (r = 0.468; p = 0.037). CONCLUSION: Significant improvements were observed after the period of observation. However, the fitness baseline level and the accumulated training load in the small-sided games seem to have no significant impact on the observed improvements.

Objectively measuring the association between the built environment and physical activity: a systematic review and reporting framework.

BACKGROUND: Objective measures of built environment and physical activity provide the opportunity to directly compare their relationship across different populations and spatial contexts. This systematic review synthesises the current body of knowledge and knowledge gaps around the impact of objectively measured built environment metrics on physical activity levels in adults (≥ 18 years). Additionally, this review aims to address the need for improved quality of methodological reporting to evaluate studies and improve inter-study comparability though the creation of a reporting framework. METHODS: A systematic search of the literature was conducted following the PRISMA guidelines. After abstract and full-text screening, 94 studies were included in the final review. Results were synthesised using an association matrix to show overall association between built environment and physical activity variables. Finally, the new PERFORM ('Physical and Environmental Reporting Framework for Objectively Recorded Measures') checklist was created and applied to the included studies rating them on their reporting quality across four key areas: study design and characteristics, built environment exposures, physical activity metrics, and the association between built environment and physical activity. RESULTS: Studies came from 21 countries and ranged from two days to six years in duration. Accelerometers and using geographic information system (GIS) to define the spatial extent of exposure around a pre-defined geocoded location were the most popular tools to capture physical activity and built environment respectively. Ethnicity and socio-economic status of participants were generally poorly reported. Moderate-to-vigorous physical activity (MVPA) was the most common metric of physical activity used followed by walking. Commonly investigated elements of the built environment included walkability, access to parks and green space. Areas where there was a strong body of evidence for a positive or negative association between the built environment and physical activity were identified. The new PERFORM checklist was devised and poorly reported areas identified, included poor reporting of built environment data sources and poor justification of method choice. CONCLUSIONS: This systematic review highlights key gaps in studies objectively measuring the built environment and physical activity both in terms of the breadth and quality of reporting. Broadening the variety measures of the built environment and physical activity across different demographic groups and spatial areas will grow the body and quality of evidence around built environment effect on activity behaviour. Whilst following the PERFORM reporting guidance will ensure the high quality, reproducibility, and comparability of future research.

Season Match Loads of a Portuguese Under-23 Soccer Team: Differences between Different Starting Statuses throughout the Season and Specific Periods within the Season Using Global Positioning Systems.

This study aimed to quantify the external match loads (EMLs) of a Portuguese u-23 soccer team, competing at the highest national level for the age group, comparing players with different starting status throughout a competitive season and specific blocks. Thirty-five outfield soccer players were split into three groups for the entire season analysis and for each 3-month block, based on the percentage of games played as a starter. The three groups consisted of "starters" (≥55% of the games as a starter), "fringe" (30−54%), and "non-starters" (<30%). EMLs were recorded using 10 Hz GPS technology throughout the whole season (26 matches). Differences (p < 0.05) were found for total distance (TD), exposure time, and the number of accelerations and decelerations between starters and non-starters throughout the season (d = 0.73 to 1.08), and within each block (d = 0.59 to 1.68). Differences were also found between starters and fringe players for the number of accelerations in Block 2 (p = 0.03; d = 0.69), and TD (p = 0.006; d = 1) and exposure time (p = 0.006; d = 0.95) in Block 3. Differences in the EML were almost always accompanied by large differences in game time. Our results highlight the differences in the EML of starters and non-starters, emphasizing the need for compensatory training, especially with players that obtain significantly less playing time, to prepare the players for match demands (e.g., high-intensity efforts such as sprinting, accelerations, and decelerations).

Development of a method for walking step observation based on large-scale GPS data.

BACKGROUND: Widespread use of smartphones has enabled the continuous monitoring of people's movements and physical activity. Linking global positioning systems (GPS) data obtained via smartphone applications to physical activity data may allow for large-scale and retrospective evaluation of where and how much physical activity has increased or decreased due to environmental, social, or individual changes caused by policy interventions, disasters, and infectious disease outbreaks. However, little attention has been paid to the use of large-scale commercial GPS data for physical activity research due to limitations in data specifications, including limited personal attribute and physical activity information. Using GPS logs with step counts measured by a smartphone application, we developed a simple method for daily walking step estimation based on large-scale GPS data. METHODS: The samples of this study were users whose GPS logs were obtained in Sendai City, Miyagi Prefecture, Japan, during October 2019 (37,460 users, 36,059,000 logs), and some logs included information on daily step counts (731 users, 450,307 logs). The relationship between land use exposure and daily step counts in the activity space was modeled using the small-scale GPS logs with daily step counts. Furthermore, we visualized the geographic distribution of estimated step counts using a large set of GPS logs with no step count information. RESULTS: The estimated model showed positive relationships between visiting high-rise buildings, parks and public spaces, and railway areas and step counts, and negative relationships between low-rise buildings and factory areas and daily step counts. The estimated daily step counts tended to be higher in urban areas than in suburban areas. Decreased step counts were mitigated in areas close to train stations. In addition, a clear temporal drop in step counts was observed in the suburbs during heavy rainfall. CONCLUSIONS: The relationship between land use exposure and step counts observed in this study was consistent with previous findings, suggesting that the assessment of walking steps based on large-scale GPS logs is feasible. The methodology of this study can contribute to future policy interventions and public health measures by enabling the retrospective and large-scale observation of physical activity by walking.

Impact of Sudden Rule Changes on Player Injuries and Performance: Insights from Australian Football.

This study investigated the effects of reduced quarter time due to COVID-19 pandemic rule changes, on running performance and injuries in Australian Football. Microsensor data for eight matches performed by the same 17 players were compared between the 2019 (standard) and 2020 (COVID-19) seasons using linear and generalised mixed models. Injury rates were assessed in 34 players across the full 2019 season, and 32 players across the full 2020 season. The total distance (ES = 1.28 [0.55 to 2.02]), high-speed (>18 km/h) (ES = 0.44 [-0.24 to 1.12]) and very highspeed (>24 km/h) (ES = 0.27 [-0.41 to 0.94]) distances, PlayerLoad™ (ES = 0.96 [0.25 to 1.67]), high-intensity efforts (ES = 0.48 [-0.20 to 1.16]), and accelerations (ES = 0.33 [-0.34 to 1.01]) were smaller (p ≤ 0.01) for the 2020 than the 2019 season. Expressed relative to playing time, distance (ES=-0.38 [-1.06 to 0.30]), PlayerLoad™ (ES = -0.27 [-0.94 to 0.41]), and acceleration efforts (ES = -0.50 [-1.18 to 0.18]) were greater (p < 0.05) for the 2020 than the 2019 season. No significant differences in maximum ball-in-play periods nor the difference between the 1st and 4th quarters were evident. Injury rates remained similar between 2019 (3.36 per game) and 2020 (3.55 per game). However, the proportion of injuries that led to lost time (missed games) was greater for the 2020 (38%) than 2019 season (24%). The changes in the rules had a profound impact on player performance and increased the likelihood of time loss injuries.