Leveraging Ecological Momentary Assessment Data to Characterize Individual Mobility: Exploratory Pilot Study in Rural Uganda.

BACKGROUND: The geographical environments within which individuals conduct their daily activities may influence health behaviors, yet little is known about individual-level geographic mobility and specific, linked behaviors in rural low- and middle-income settings. OBJECTIVE: Nested in a 3-month ecological momentary assessment intervention pilot trial, this study aims to leverage mobile health app user GPS data to examine activity space through individual spatial mobility and locations of reported health behaviors in relation to their homes. METHODS: Pilot trial participants were recruited from the Rakai Community Cohort Study-an ongoing population-based cohort study in rural south-central Uganda. Participants used a smartphone app that logged their GPS coordinates every 1-2 hours for approximately 90 days. They also reported specific health behaviors (alcohol use, cigarette smoking, and having condomless sex with a non-long-term partner) via the app that were both location and time stamped. In this substudy, we characterized participant mobility using 3 measures: average distance (kilometers) traveled per week, number of unique locations visited (deduplicated points within 25 m of one another), and the percentage of GPS points recorded away from home. The latter measure was calculated using home buffer regions of 100 m, 400 m, and 800 m. We also evaluated the number of unique locations visited for each specific health behavior, and whether those locations were within or outside the home buffer regions. Sociodemographic information, mobility measures, and locations of health behaviors were summarized across the sample using descriptive statistics. RESULTS: Of the 46 participants with complete GPS data, 24 (52%) participants were men, 30 (65%) participants were younger than 35 years, and 33 (72%) participants were in the top 2 socioeconomic status quartiles. On median, participants traveled 303 (IQR 152-585) km per week. Over the study period, participants on median recorded 1292 (IQR 963-2137) GPS points-76% (IQR 58%-86%) of which were outside their 400-m home buffer regions. Of the participants reporting drinking alcohol, cigarette smoking, and engaging in condomless sex, respectively, 19 (83%), 8 (89%), and 12 (86%) reported that behavior at least once outside their 400-m home neighborhood and across a median of 3.0 (IQR 1.5-5.5), 3.0 (IQR 1.0-3.0), and 3.5 (IQR 1.0-7.0) unique locations, respectively. CONCLUSIONS: Among residents in rural Uganda, an ecological momentary assessment app successfully captured high mobility and health-related behaviors across multiple locations. Our findings suggest that future mobile health interventions in similar settings can benefit from integrating spatial data collection using the GPS technology in mobile phones. Leveraging such individual-level GPS data can inform place-based strategies within these interventions for promoting healthy behavior change.

An Integrative Review of the Feasibility and Effects of the Use of Location-Tracking Devices by Persons Living With Cognitive Impairment.

OBJECTIVES: This study aimed to examine the effects of location-tracking devices on persons living with cognitive impairment, investigate facilitators of and barriers to using the devices, and provide future directions for the use of the devices. METHODS: An integrative review was conducted using 5 databases: PubMed, Embase, Web of Science, CINAHL, and Scopus. From the 1429 initially identified studies, 10 were included in the review. RESULTS: Location-tracking devices benefited persons living with cognitive impairment and their informal caregivers. The devices brought more independence to persons living with cognitive impairment, allowing them to go outside and feel safer there. Furthermore, the devices reduced the caregivers' worries about their loved ones being lost. CONCLUSIONS: Location-tracking devices have the potential to increase independence in persons living with cognitive impairment and to decrease psychological stress in informal caregivers. In the future, ways to minimize the barriers to using location-tracking devices need to be determined.

Defining Worst-Case-Scenario Thresholds in Soccer: Intensity Versus Volume.

PURPOSE: This study aimed to enhance the understanding of soccer match peak demands by describing worst-case scenario (WCS) and time spent above 80% and 90% of the WCS for total distance (TD) and high-speed running (HSR). The investigation considered playing level (first team vs under-19 [U19] team) and playing position (center backs, fullbacks, midfielders, and forwards) to assess how WCS and the time spent above specific thresholds vary across different populations. METHODS: Data from 31 players in a professional Italian soccer club were collected during the 2022-23 season. Microtechnology devices tracked physical activity during matches. Players were categorized by position, and WCS was determined using rolling averages over a 1-minute period. Time spent above 80% and 90% of WCS for TD and HSR was calculated. RESULTS: The U19 team exhibited higher HSR WCS compared with the first team (∼63 m·min-1 vs ∼56 m·min-1). Midfielders recorded the highest TD WCS (∼208 m·min-1), and forwards exhibited the highest HSR WCS (∼70 m·min-1). The first team spent significantly more time above 80% (∼6 min) and 90% (∼1 min) of TD WCS. Midfielders spent significantly more time above the 80% (∼7 min) of TD WCS, while forwards above the 80% (∼2 min) of HSR WCS. CONCLUSIONS: The study emphasizes that WCS used alone may not sufficiently capture real match intensity. Considering the time spent above specific thresholds provides additional insights (ie, between-levels differences and position). Practitioners should consider both WCS and time spent above thresholds for individualized training prescriptions, reflecting differences in playing roles.

Need a break? The locomotor and tackle pacing profile and loads of women's rugby league match-play following various between-match turnaround durations.

OBJECTIVES: The study investigated the locomotor and tackle pacing profile and loads of female rugby league players following various between-match turnaround durations. Specifically, the study examined the (1) pacing of locomotor and tackle loads across the time-course of a match and; (2) whole-match and peak locomotor and tackle loads of match-play. METHODS: Microtechnology data were collected from elite female rugby league players (n = 172) representing all National Rugby League Women's teams (n = 6 teams) across two seasons. Players were categorised into backs, adjustables, forwards or interchange players. Data was calculated for the whole-match (m), per minute (m.min-1) and peak (running: m.min-1; acceleration: m.s-2) locomotor and tackle loads (number and efficiency (%)) of match-play. The pacing as well as the locomotor and tackle loads of match-play were examined following short (≤6 days), normal (7 days) or long (≥8 days) turnarounds. RESULTS: The pacing profile of playing positions varied across short, normal and long match turnarounds. Trivial to moderate differences existed in the whole-match, per minute and peak locomotor loads across match turnaround durations (effect size ≤ 1.2). CONCLUSIONS: Following various between-match turnaround durations (i.e., short, normal and long match turnarounds), there were variations in the locomotor and tackle pacing profile and loads whereby, the pacing profile of positional groups was more affected than the load profile. The findings can be used in applied settings to guide the recovery strategies and training plans of female rugby league players to optimise performance and wellbeing across various match turnaround durations.

Comparison of Australian Football League Women's athletes match day energy and nutrient intake to recommendations.

AIMS: This cross-sectional observational study quantified Australian Football League Women's athletes' match volume, and compared match-day dietary intakes against recommendations. METHODS: Self-report, direct observation, and fluid measurements determined dietary intake (n = 17, 25 ± 4.5 years, 22.8 ± 1.8 kg/m2) on five home match days (early or late starting). Global positioning system software captured match volume. Linear mixed effects models evaluated differences in early versus late match volume and nutrient intakes. Data are presented as mean ± standard deviation. RESULTS: Athletes covered 6712 ± 622 m during matches, with similar numbers of very high-intensity running efforts over equal distances in early and late matches (early vs. late efforts [no.]: 8.5 ± 4.9 vs. 9.5 ± 5.5; distance [m]: 203 ± 127 vs. 212 ± 113). Across all match days, 71% (n = 12) of athletes met their predicted daily energy requirements. However, 82% (n = 14) failed to meet minimum daily carbohydrate recommendations; intake was lower on early compared with late match days (4.7 g/day vs. 5.4 g/kg/day, p = 0.027). On average, no athletes met carbohydrate recommendations in the 2 h prior to a match and only 24% (n = 4) met recommendations during matches. All athletes met post-match carbohydrate and protein requirements. CONCLUSION: Athletes cover large distances during games with frequent bursts of high-intensity running. However, they do not adjust their intake to meet the energy demands of competition, with inadequate fuelling prior to and during matches. These findings emphasise the need for greater athlete education and dietary support to maximise strategic fuelling to optimise athletic performance.

Dirt Track Surface Preparation and Associated Differences in Speed, Stride Length, and Stride Frequency in Galloping Horses.

In racehorses, the risk of musculoskeletal injury is linked to a decrease in speed and stride length (SL) over consecutive races prior to injury. Surface characteristics influence stride parameters. We hypothesized that large changes in stride parameters are found during galloping in response to dirt racetrack preparation. Harrowing of the back stretch of a half-mile dirt racetrack was altered in three individual lanes with decreasing depth from the inside to the outside. Track underlay compaction and water content were changed between days. Twelve horses (six on day 2) were sequentially galloped at a target speed of 16 ms-1 across the three lanes. Speed, stride frequency (SF), and SL were quantified with a GPS/GNSS logger. Mixed linear models with speed as covariate analyzed SF and SL, with track hardness and moisture content as fixed factors (p < 0.05). At the average speed of 16.48 ms-1, hardness (both p < 0.001) and moisture content (both p < 0.001) had significant effects on SF and SL. The largest difference in SL of 0.186 m between hardness and moisture conditions exceeded the 0.10 m longitudinal decrease over consecutive race starts previously identified as injury predictor. This suggests that detailed measurements of track conditions might be useful for refining injury prediction models.

Resource selection by Sarda cattle in a Mediterranean silvopastoral system.

Knowledge of how grazing cattle utilize heterogeneous landscapes in Mediterranean silvopastoral areas is scarce. Global positioning systems (GPS) to track animals, together with geographic information systems (GIS), can relate animal distribution to landscape features. With the aim to develop a general spatial model that provides accurate prediction of cattle resource selection patterns within a Mediterranean mountainous silvopastoral area, free-roaming Sarda cows were fitted with GPS collars to track their spatial behaviors. Resource selection function models (RSF) were developed to estimate the probability of resource use as a function of environmental variables. A set of over 500 candidate RSF models, composed of up to five environmental predictor variables, were fitted to data. To identify a final model providing a robust prediction of cattle resource selection pattern across the different seasons, the 10 best models (ranked on the basis of the AIC score) were fitted to seasonal data. Prediction performance of the models was evaluated with a Spearman correlation analysis using the GPS position data sets previously reserved for model validation. The final model emphasized that watering point, elevation, and distance to fences were important factors affecting cattle resource-selection patterns. The prediction performances (as Spearman rank correlation scores) of the final model, when fitted to each season, ranged between 0.7 and 0.94. The cows were more likely to select areas lower in elevation and farther from the watering point in winter than in summer (693 ± 1 m and 847 ± 13 m vs. 707 ± 1 m and 635 ± 21 m, respectively), and in spring opted for the areas furthest from the water (963 ± 12). Although caution should be exercised in generalizing to other silvopastoral areas, the satisfactory Spearman correlations scores from the final RSF model applied to different seasons indicate resource selection function is a powerful predictive model. The relative importance of the individual predictors within the model varied among the different seasons, demonstrating the RSF model's ability to interpret changes in animal behavior at different times of the year. The RSF model has proven to be a useful tool to interpret the spatial behaviors of cows grazing in Mediterranean silvopastoral areas and could therefore be helpful in managing and preserving ecosystem services of these areas.

Optimization of training for professional rugby union players: investigating the impact of different small-sided games models on GPS-derived performance metrics.

Introduction: Professional rugby union players can improve their performance by engaging in small-sided games (SSGs), which simulate the movement patterns of the game. This study collected metrics related to running performance and mechanical workload and their relative values from both forward and back positions, aiming to explore the impact of different SSGs factors on athlete workload, as well as the workload difference between official games (OGs) and SSGs. Methods: The monitored GPS data were collected from SSGs with different player numbers and pitch sizes (five sessions), SSG rules (5 weeks, four sessions per week), and OGs conducted throughout the year. Additionally, the study compared changes in players' sprinting performance before and after two SSG sessions. Results: Backs had greater workload than forwards. Less space and number of players SSG (4 vs. 4, 660 m2) was conducive to facilitating training for players in acceleration and deceleration. Conversely, larger spaces were associated with improved running performance. However, the introduction of a floater had no significant impact on performance improvement. Additionally, the 7 vs. 4 model (seven players engaged with four opponents) resulted in the greatest workload during medium-hard accelerations (F = 52.76-88.23, p < 0.001, ηp 2 = 0.19-0.28). Japan touch model allowed for more high-speed running training (F = 47.93-243.55, p < 0.001, ηp 2 = 1.52). The workload performed by SSGs can almost cover that of OGs (F = 23.36-454.21, p < 0.05, ηp 2 = 0.03-0.57). In the context of ηp 2, values around 0.01, 0.06 and 0.14 indicate small, medium and large effects respectively. Discussion: However, given the significantly higher workload of SSGs and the slight decrease in sprinting performance, further research is required to examine the training patterns of SSGs. This study provided insight into the impact of player numbers, pitch size, and rules on rugby-specific SSGs. Coaches should optimize SSG setups for enhanced training outcomes, ensuring the long-term development of physical capacity, technical and tactical skills.

A Qualitative Exploration of Attitudes Toward Global Positioning System Tracking and Ecological Momentary Assessment Among Individuals in Substance Use Treatment.

BACKGROUND: The use of tracking technology in substance use research can uncover the role of contextual factors, such as social networks and environmental cues, in triggering cravings and precipitating return to use. Few studies have explored the opinions of individuals in substance use treatment related to tracking technology. METHODS: We conducted 30 semi-structured interviews with individuals in substance use treatment facilities in Connecticut and Georgia. Interviews were not limited to individuals with any specific substance use disorder. Interviewers described a hypothetical study involving ecological momentary assessment and global positioning system tracking to examine place-based predictors of substance use. Participants were invited to share reactions to this description. We used thematic analysis to identify themes in participant perceptions of this hypothetical research study. RESULTS: Most participants shared positive opinions about study participation and expressed little to no concern about the tracking components. Participant concerns focused on the security of their information and the potential burden of responding to study questions. Participants largely understood the importance of study participation for promoting greater understanding of substance use and identified potential therapeutic effects of study participation on their own recovery. CONCLUSIONS: Individuals in substance use treatment expressed little concern with research studies or interventions incorporating mobile-tracking elements. Future studies should explore the responsible use of tracking elements in recovery support interventions.

Evaluating movement-based methods for estimating the frequency and timing of parturition in mule deer.

BACKGROUND: Information on reproduction of harvested species such as mule deer (Odocoileus hemionus) is vital for conservation and management. Furthermore, parturition in ungulates may be detected using patterns of movement logged by GPS transmitters. Several movement-based methods have been developed to detect parturition in ungulates including the Peterson method, behavioral change point analysis (BCPA), rolling minimum convex polygons (rMCP), individual-based method (IBM), and population-based method (PBM). Our objectives were to (1) test the accuracy and the precision of each previously described method and (2) develop an improved method optimized for mule deer that incorporated aspects of the other methods. METHODS: We determined parturition timing and status for female mule deer fitted with GPS collars and implanted with vaginal implant transmitters (VITs). We used movement patterns before and after parturition to set movement thresholds for each movement-based method. Following model training, we used location and birth date data from an external dataset to test the effectiveness of each movement-based method. Additionally, we developed a novel method for detecting parturition called the analysis of parturition indicators (API). We used two regression analyses to determine the accuracy and precision of estimates generated by each method. RESULTS: The six methods we employed varied in accuracy, with the API, rMCP, and BCPA being most accurate. Precision also varied among methods, with the API, rMCP, and PBM generating the most precise estimates of parturition dates. The API and the rMCP performed similarly and better overall than any of the other existing methods. CONCLUSIONS: We found that movement-based methods could be used to accurately and precisely detect parturition in mule deer. Further, we determined that the API and rMCP methods had the greatest overall success at detecting parturition in mule deer. The relative success of the API and rMCP may be attributed to the fact that both methods use home range size to detect parturition and are validated using known parturition dates of collared deer. We present the API as an efficient method of estimating birth status and timing of parturition of mule deer fitted with GPS transmitters, as well as affirm the effectiveness of a previously developed method, rMCP.

Quantifying Offense and Defense Workloads in Professional Rugby Union.

PURPOSE: Rugby union is a contact team sport demanding high levels of physical capacity, and understanding the match workloads can be useful to inform training. In this study, the factors influencing locomotion and contact workloads for offensive and defensive ball-in-play periods are quantified. METHODS: Locomotion and contact metrics were collected from global positioning system units and videos for 31 professional players of a Super Rugby team across 14 games in the 2021 season. Data were analyzed with a generalized mixed-model procedure that included effects for type of play, playing position, match outcome, and ball-in-play time. Magnitudes were assessed with standardization, and evidence for substantial magnitudes was derived from sampling uncertainty. RESULTS: When offense was compared to defense, most metrics showed decisively substantial increases (small to moderate) for forwards and backs. There was decisive evidence that locomotion metrics were substantially lower (large differences) and contact metrics were higher (very large differences) when comparing forwards to backs on offense and defense. When winning was compared to losing, there was good evidence that forwards experienced small increases in overall workload on defense, and backs experienced a small increase in high-speed running and a moderate decrease in contacts on offense. Match-to-match changes associated with ball-in-play time, attributed to fatigue, were decisive (moderate to very large) across most metrics for forwards and backs in offense and defense. CONCLUSIONS: The increased locomotion and contact workloads in offensive periods and the differing physical requirements between positions and match outcomes for both types of play are novel findings that should aid practitioners in designing effective training.

Application of arbitrary and individualized load quantification strategies over the weekly microcycle in professional soccer players.

The aims of this study were to: (a) determine the differences in external load quantification between arbitrary and individual speed thresholds over the weekly microcycle in professional soccer players, and (b) analyse the association between internal load and different external load quantification strategies (ELQSs). Ten professional outfield players were monitored during training sessions and official matches using 10 Hz GPS devices over a 6-week in-season period. The absolute and relative ("R" before the distance category) distances covered were calculated for the following external load variables: medium-intensity running distance (MIR), high-intensity running (HIR), sprint distance (SD), and very high-intensity running (VHIR). Individualized thresholds were determined based on maximal sprinting speed (MSS) and the last speed achieved during the 30-15 Intermittent Fitness Test (VIFT) of each player. In terms of match-day workload, significant differences (p < 0.05) were observed between arbitrary and individualized strategies (i.e., MSS and VIFT) for the distance covered in MIR, HIR, SD, VHIR, RHIR, RSD, and RVHIR. The MSS strategy compared to arbitrary thresholds revealed significant differences (p < 0.05) for distance covered in HIR, RHIR, and VHIR during all training sessions. The present results showed that arbitrary thresholds lead to underestimation of external load absolute and relative metrics compared to the MSS strategy throughout the microcycle. The VIFT strategy mainly revealed differences in external load quantification regarding MD compared to arbitrary thresholds. Individualized speed threshold strategies did not achieve better associations with internal load measures in comparison with arbitrary thresholds in professional soccer players.

Key Grazing Behaviours of Beef Cattle Identify Specific Genotypes of the Glutamate Metabotropic Receptor 5 Gene (GRM5).

Genotype-phenotype associations between the bovine genome and grazing behaviours measured over time and across contexts have been reported in the past decade, with these suggesting the potential for genetic control over grazing personalities in beef cattle. From the large array of metrics used to describe grazing personality behaviours (GP-behaviours), it is still unclear which ones are linked to specific genes. Our prior observational study has reported associations and trends towards associations between genotypes of the glutamate metabotropic receptor 5 gene (GRM5) and four GP-behaviours, yet the unbalanced representation of GRM5 genotypes occurring in observational studies may have limited the ability to detect associations. Here, we applied a subsampling technique to create a genotypically-balanced dataset in a quasi-manipulative experiment with free ranging cows grazing in steep and rugged terrain of New Zealand's South Island. Using quadratic discriminant analysis, two combinations of eleven GP-behaviours (and a total of fifteen behaviours) were selected to build an exploration model and an elevation model, respectively. Both models achieved ∼ 86% accuracy in correctly discriminating cows' GRM5 genotypes with the training dataset, and the exploration model achieved 85% correct genotype prediction of cows from a testing dataset. Our study suggests a potential pleiotropic effect, with GRM5 controlling multiple grazing behaviours, and with implications for the grazing of steep and rugged grasslands. The study highlights the importance of grazing behavioural genetics in cattle and the potential use of GRM5 markers to select individuals with desired grazing personalities and built herds that collectively utilize steep and rugged rangelands sustainably.

Seasonal health tracking of Australian Football League Women's athletes.

BACKGROUND: Studies evaluating the dietary intake of Australian Football League Women's (AFLW) athletes are few and limited to the preseason. This prospective observational study aims to evaluate seasonal changes in dietary intake and health parameters of professional AFLW athletes. METHODOLOGY: Dietary intake (3-day weighed food records), body composition (bioelectrical impedance analysis, skinfolds), physical performance (global positioning system, GPS), and iron status (fasted blood sample) were assessed in 19 athletes (24 ± 5 years, 170 ± 6 cm, 22.8 ± 2.1 kg/m2) at three timepoints: start of preseason, end of preseason, and end of competition season. Sociodemographic information, sports nutrition knowledge (SNK), and risk of low energy availability (LEA) questionnaires were completed at the start of preseason. RESULTS: Mean daily energy and carbohydrate (CHO) intakes were lower than recommendations across all seasons (p < 0.05). Mean daily CHO intake was highest at start of preseason (3.6 g/kg/day), decreased during preseason (3.1 g/day) and remained low during competition (3.2 g/day); >80% of players did not meet minimum recommendations at each timepoint (all, p < 0.05). The sum of seven skinfolds and fat mass (%) decreased during preseason (both, p < 0.05). Serum iron fell within recommended ranges for 95% of athletes at all timepoints. The total distance (m) and number of Very High Intensity (>21 km/h) efforts significantly increased across preseason and decreased during competition (all, p < 0.05). Nutrition knowledge was 'poor', and 42% of athletes were at risk of LEA. CONCLUSIONS: AFLW athletes do not meet energy and carbohydrate requirements across the preseason and competition seasons, which may impact health and performance if deficits are sustained.

Comparing Location Data From Smartphone and Dedicated Global Positioning System Devices: Implications for Epidemiologic Research.

In this study, we compared location data from a dedicated Global Positioning System (GPS) device with location data from smartphones. Data from the Interventions, Equity, and Action in Cities Team (INTERACT) Study, a study examining the impact of urban-form changes on health in 4 Canadian cities (Victoria, Vancouver, Saskatoon, and Montreal), were used. A total of 337 participants contributed data collected for about 6 months from the Ethica Data smartphone application (Ethica Data Inc., Toronto, Ontario, Canada) and the SenseDoc dedicated GPS (MobySens Technologies Inc., Montreal, Quebec, Canada) during the period 2017-2019. Participants recorded an average total of 14,781 Ethica locations (standard deviation, 19,353) and 197,167 SenseDoc locations (standard deviation, 111,868). Dynamic time warping and cross-correlation were used to examine the spatial and temporal similarity of GPS points. Four activity-space measures derived from the smartphone app and the dedicated GPS device were compared. Analysis showed that cross-correlations were above 0.8 at the 125-m resolution for the survey and day levels and increased as cell size increased. At the day or survey level, there were only small differences between the activity-space measures. Based on our findings, we recommend dedicated GPS devices for studies where the exposure and the outcome are both measured at high frequency and when the analysis will not be aggregate. When the exposure and outcome are measured or will be aggregated to the day level, the dedicated GPS device and the smartphone app provide similar results.

Control del entrenamiento con datos GPS y medidas subjetivas de fatiga y recuperación en futbolistas hondureños durante un periodo preparatorio para los Juegos Olímpicos de Tokio 2020/2021 / Training Monitoring With GPS Data and Subjective Measures of Fatigue and Recovery in Honduran Soccer Players During a Preparatory Period for Tokyo 2020/2021 Olympic Games / Monitoramento do treinamento com dados GPS e medidas subjetivas de fadiga e recuperação dos jogadores de futebol hondurenhos durante um período preparatório para os Jogos Olímpicos de Tóquio 2020/2021

Resumen: Introducción: El control de cargas de entrenamiento es importante para optimizar el rendimiento. Por lo tanto, se deben documentar metodologías que mejoren la preparación de selecciones nacionales en eventos como los juegos olímpicos. Objetivo: Determinar si los datos del GPS en combinación con medidas subjetivas de bienestar, fatiga y recuperación son apropiados para el control de las cargas durante un periodo preparatorio para los Juegos Olímpicos. Metodología: Participaron 22 jugadores profesionales sub-23 durante 5 microciclos y 27 sesiones de entrenamiento. Se recopilaron datos de carga externa a través de un sistema global de posicionamiento (GPS): Distancia total (DT), zonas de rendimiento Z0 (0-15 km/h), Z1 (15.1-18 km/h), Z2 (18.1-24 km/h), Z3 (>24.1 km/h)), velocidad máxima (Vmax (km/h)), aceleraciones (>2.5m/s2) y desaceleraciones (<2.5m/s2). También, se obtuvo la carga interna a través de medidas subjetivas de percepción del esfuerzo (RPE), calidad de la recuperación (TQR), predisposición para entrenar (RTT%) derivada de las variables de calidad del sueño, dolor muscular, niveles de energía, estado de ánimo, estrés, calidad de la alimentación y la salud. Luego se calculó la ratio subjetiva de fatiga-recuperación (F-R). Se aplicó un test ANOVA, análisis de componentes principales (ACP) y una regresión múltiple lineal. Resultados: Las variables DT (p=0.00 TE=0.22), Z0 (p= 0.00 TE=0.08), Z2 (p=0.00 TE= 0.05), Vmax (p=0.00 TE=0.42), suma de aceleración y deceleración (p=0.00 TE=0.08) y valores relativos de la carga/min (p=0.00 TE=0.17) se identificaron como variables más sensibles al cambio de la carga entre microciclos. El RTT% y ratio subjetivo F-R mostraron un tamaño del efecto moderado (p=0.04 TE=0.06 y p=0.06 TE=0.06), pero fueron sensibles al cambio entre los microciclos. El ACP extrajo 15 variables GPS y 11 variables subjetivas que explicaron el 78% de la varianza de la carga de entrenamiento. Conclusión: Utilizar datos GPS junto con medidas subjetivas implicadas en la fatiga-recuperación puede ser una buena estrategia para el control de la carga de entrenamiento en futbolistas.

Abstract: Background: Training control is essential to optimize performance. Therefore, methodologies that improve the preparation of national teams in events such as the Olympic Games should be documented. Purpose: To determine whether GPS data in combination with subjective measures of well-being, fatigue and recovery are appropriate for load monitoring during a preparatory period for the Olympic Games. Methodology: Twenty-two under-23 professional players participated during 5 micro-cycles and 27 training sessions. External load data was collected via a global positioning system (GPS): Total distance (DT), performance zones Z0 (0-15 km/h), Z1 (15.1-18 km/h), Z2 (18.1 -24 km/h), Z3 (>24.1 km/h), maximum speed (km/h), accelerations (>2.5m/s.) and decelerations (<2.5m/s.). Also, internal load was obtained through subjective measures of Rating Perceived Exertion (RPE), Total Quality Recovery (TQR), Readiness to Train (RTT%) obtained from the sleep quality, muscle pain, energy levels, mood, stress, food quality and health. The subjective rate of fatigue-recovery (F-R) was then calculated. An ANOVA test, Principal Component Analysis (PCA) and multiple linear regression were applied. Results: the variables DT (p=0.00 ES=0.22), Z0 (p= 0.00 TE=0.08), Z2 (p=0.00 ES= 0.05), maximum speed (p= 0.00 ES=0.42), sum of acceleration and deceleration (p=0.00 ES=0.08) and values relative to load/min (p=0.00 ES=0.17) were identified as variables more sensitive to load change between micro-cycles. RTT% and subjective rate F-R showed a moderate effect size (p=0.04 ES=0.06 and p=0.06 ES=0.06), but were sensitive to change between micro-cycles. PCA extracted 15 GPS variables and 11 subjective variables that explained 78% of the training load variance. Conclusion: Using GPS data together with subjective measures involved in fatigue-recovery may be a good strategy to control training load in footballers.

Resumo: Introdução: O monitoramento das cargas de treinamento é importante para otimizar o desempenho. Portanto, as metodologias devem ser documentadas para melhorar a preparação das equipes nacionais para eventos como os Jogos Olímpicos. Objetivo: Determinar se os dados GPS em combinação com medidas subjetivas de bem-estar, fadiga e recuperação são apropriados para o monitoramento da carga durante um período preparatório para os Jogos Olímpicos. Metodologia: 22 jogadores profissionais U-23 participaram durante 5 microciclos e 27 sessões de treinamento. Os dados de carga externa foram coletados através de um sistema de posicionamento global (GPS): distância total (DT), zonas de desempenho Z0 (0- 15 km/h), Z1 (15,1-18 km/h), Z2 (18,1-24 km/h), Z3 (>24,1 km/h), velocidade máxima (Vmax (km/h)), acelerações (>2,5m/ s2) e desacelerações (<2,5m/s2). Além disso, a carga interna foi obtida através de medidas subjetivas de percepção do esforço (RPE), qualidade de recuperação (TQR), predisposição para o treinamento (RTT%) derivada das variáveis de qualidade do sono, dor muscular, níveis de energia, humor, estresse, qualidade alimentar e saúde. Posteriormente a taxa subjetiva de fadiga-recuperação (F-R) foi calculada. Um teste ANOVA, análise de componentes principais (ACP) e regressão linear múltipla foram aplicados. Resultados: As variáveis DT (p=0,00 TE=0,22), Z0 (p= 0,00 TE=0,08), Z2 (p=0,00 TE= 0,05), Vmax (p=0,00 TE=0,42), soma de aceleração e desaceleração (p=0,00 TE=0,08) e valores de carga relativa/min (p=0,00 TE=0,17) foram identificadas como as variáveis mais sensíveis à mudança de carga entre microciclos. RTT% e a relação F-R subjetiva mostraram tamanho de efeito moderado (p=0,04 TE=0,06 e p=0,06 TE=0,06 TE=0,06), mas foram sensíveis à mudança entre microciclos. O ACP extraiu 15 variáveis GPS e 11 variáveis subjetivas que explicaram 78% da variância na carga de treinamento. Conclusão: O uso de dados GPS junto com medidas subjetivas envolvidas na fadiga#recuperação pode ser uma boa estratégia para o monitoramento da carga de treinamento em jogadores de futebol.

Quantification of training load across two competitive seasons in elite senior and youth male soccer players from an English Premiership club.

This study aimed to compare the daily training load (TL) in first-team and U-18 soccer players from an English Premiership club. 36 first-team (age 23.2 ± 5.9 years, weight 75.2 ± 8.1 kg, height 1.83 ± 0.06 m), and 22 U-18 players (age 17.5 ± 1.1 years, weight 71.1 ± 8.2 kg, height 1.78 ± 0.08 m) participated. GPS metrics were measured during all pitch training sessions throughout the 2020-21 and 2021-22 seasons. Linear mixed-effect model analyses revealed that, irrespective of training day, U-18 players covered greater total and explosive distance than first-team players, and performed a higher number of accelerations and decelerations, whereas first-team players covered greater sprint distance. Irrespective of the team, all examined variables were greater at match-day (MD)-3, while the number of accelerations and decelerations were higher at MD-4. Significant team-by-training day interactions revealed that U-18 players covered greater total and high-intensity distances than first-team players at MD-4, MD-2, and MD-1, whereas first-team players covered greater total and high-intensity distances at MD-3. Sprint distance was greater for first-team players at MD-3 and MD-4, while explosive distance was greater for U-18 players at MD-2. Also, U-18 players performed a higher number of accelerations than first-team players at MD-3 and MD-2, and a higher number of decelerations at MD-4. The present results provide novel information on TL patterns in English Premiership soccer and contribute to understanding how training methods to physically develop players are implemented in different countries and leagues.

Micro‒Global Positioning Systems for Identifying Nightly Opportunities for Marburg Virus Spillover to Humans by Egyptian Rousette Bats.

Marburg virus disease, caused by Marburg and Ravn orthomarburgviruses, emerges sporadically in sub-Saharan Africa and is often fatal in humans. The natural reservoir is the Egyptian rousette bat (ERB), which sheds virus in saliva, urine, and feces. Frugivorous ERBs discard test-bitten and partially eaten fruit, potentially leaving infectious virus behind that could be consumed by other susceptible animals or humans. Historically, 8 of 17 known Marburg virus disease outbreaks have been linked to human encroachment on ERB habitats, but no linkage exists for the other 9 outbreaks, raising the question of how bats and humans might intersect, leading to virus spillover. We used micro‒global positioning systems to identify nightly ERB foraging locations. ERBs from a known Marburg virus‒infected population traveled long distances to feed in cultivated fruit trees near homes. Our results show that ERB foraging behavior represents a Marburg virus spillover risk to humans and plausibly explains the origins of some past outbreaks.

Application of Adaptive Robust Kalman Filter Base on MCC for SINS/GPS Integrated Navigation.

In this paper, an adaptive and robust Kalman filter algorithm based on the maximum correntropy criterion (MCC) is proposed to solve the problem of integrated navigation accuracy reduction, which is caused by the non-Gaussian noise and time-varying noise of GPS measurement in complex environment. Firstly, the Grubbs criterion was used to remove outliers, which are contained in the GPS measurement. Then, a fixed-length sliding window was used to estimate the decay factor adaptively. Based on the fixed-length sliding window method, the time-varying noises, which are considered in integrated navigation system, are addressed. Moreover, a MCC method is used to suppress the non-Gaussian noises, which are generated with external corruption. Finally, the method, which is proposed in this paper, is verified by the designed simulation and field tests. The results show that the influence of the non-Gaussian noise and time-varying noise of the GPS measurement is detected and isolated by the proposed algorithm, effectively. The navigation accuracy and stability are improved.

Validity and Reliability of Polar Team Pro and Playermaker for Estimating Running Distance and Speed in Indoor and Outdoor Conditions.

Although global positioning systems and inertial measurement unit systems are often used to quantify physical variables in training, both types of systems need to be compared, considering their frequent use in measuring physical loads. Thus, the purpose of our study was to test the reliability and validity of speed and distance run measurements at different intensities in indoor and outdoor conditions made by Polar Team Pro and Playermaker. Four participants (age = 30.0 ± 5.1 years, body mass = 76.3 ± 5.3 kg, height = 1.79 ± 0.09 m), each wearing three Polar Team Pro and two Playermaker sensors, performed 100 m runs with different prescribed intensities (i.e., criterion measure) varying from 8 to 24 km h-1, in a straight line and/or rectangle under indoor and outdoor conditions. Both systems underestimated total distance; Playermaker underestimated speed, the extent of which increased as speed increased, while Polar Team Pro overestimated mean speed at 8 km h-1 for the straight-line condition. No differences emerged in mean speed estimated by Polar Team Pro at any intensities other than 20 km h-1, which was underestimated by 2%. The reliability of the sensors was good, given a coefficient of variation (CV) of <2% for all conditions except when measuring indoor conditions with Polar Team Pro (CV ≈ 10%). Intraclass correlations (ICCs) for consistency within the sensors varied from 0.47 to 0.99, and significantly lower ICCs were documented at 8, 10, and 12 km h-1. Both systems underestimated distance measured in indoor and outdoor conditions, and distance validity in different intensities seemed to worsen as speeds increased. Although Polar Team Pro demonstrated poor validity and reliability in indoor conditions, both systems exhibited good reliability between their sensors in outdoor conditions, whereas the reliability within their sensors varied with different speeds.