scholarly journals ANALYSIS OF HIGH-SPEEDRUNNING AND SPRINT RUNNING IN ELITE FEMALE FOOTBALL COMPETITIONS

2021 ◽  
Author(s):  
Oana-Ruxandra Stîncel ◽  
Cristian Lazăr ◽  
Vlad Nicoară ◽  
Mihaela Oravițan
Keyword(s):  
High Speed ◽  
Sampling Rate ◽  
Maximum Speed ◽  
Published Data ◽  
Physical Conditioning ◽  
Running Speed ◽  
Low Speed ◽  
Total Distance ◽  
Sprint Running ◽  
High Level

Introduction: Although football is recognized as the fastest growing sport globally, scientific literature on female footballis still limited. Available published data in understanding the physical demands of female football players have described the necessity of a high level of physical conditioning during matches with average heart rates of 84-86% maximum heart rate and an average of 9.1-11.9 km in total distance covered in the running. The most commonly utilized physical performance measures reported are high-speed running (19km/h-23km/h) and sprinting (>23 km/h). A better understanding of football's physical, technical and tactical demands has resulted from investigations of both training and matches by wearing a global positioning system unit.Objective: This study aimed to assess the running speed and the proportions of different types of running during official competitions in elite female football players.Material and Method: A total of 22 female players (16 seniors and six juniors) that are part of a Romanian First League female football team -Politehnica Timisoara, have been monitored for running speed and covered distance in 6 official matches, which represent a quarter of the championship period. The assessment period was ten weeks (August-October 2021). The monitored parameters (total distance, distance/minute, low speed running, high speed running, sprint running, and maximum speed) wereobtained using K-Sport GPS with a high sampling rate of 50 Hz.Results: During the six analyzed matches the following average values were found: total covered distance -7906.33 ± 1176.68 m, distance/minute -90.83 ± 3.72 m/min, low-speed running distance-7598.50 ± 1102.16 m, high-speed running distance -308 ± 101.31 m, sprint running distance -69.50 ± 28.54 m, and maximum speed -25.13 ± 0.84 km/h.Conclusion: Regarding the monitored parameters (total distance, average speed, proportion of different speed running, maximum speed), we observed a constancy between different matches. During female football matches, high-speed running and sprinting covered 4.77% of the total distance. Based on this data, a future training objective would be the enhancement of this percentage in order to optimize the key moments of the matches.

scholarly journals Study on the optimization of linear induction motor traction system for fast-speed maglev train

2018 ◽  
Vol 4 (3 suppl. 1) ◽  
pp. 156-164
Author(s):  
Ying Yang ◽  
Jiangmin Deng ◽  
Laisheng Tong ◽  
Xiaoсhun Li ◽  
Qibiao Peng ◽  
...  
Keyword(s):  
Induction Motor ◽  
High Speed ◽  
Input Voltage ◽  
Force Characteristic ◽  
Maximum Speed ◽  
Maglev Train ◽  
Linear Induction ◽  
Low Speed ◽  
Linear Induction Motor ◽  
Fast Speed

Background: The short stator linear induction motor (LIM) is normally used in medium-low speed maglev train. The restriction by mounting space on bogie and motor input voltage from the third power supply rail lead that the maximum speed of medium-low speed maglev train can reach no more than 120 km/h. Aim: In this paper, by means of the LIM design optimization, improvement of the LIM force characteristic in high speed range, the maximum speed of medium-low speed maglev train can reach 160 km/h. Methods: After comparing the LIM theoretical calculation and actual test data, it shows that the new designed LIM is effective. Conclusion: Afterwards, by installing the new designed LIMs, the traditional medium-low speed maglev train becomes a fast-speed maglev train, and it has a bright future in transportation applications.

The reliability and accuracy of Polar Team Pro GPS units

2020 ◽  
pp. 175433712097666
Author(s):  
Zeki Akyildiz ◽  
Mehmet Yildiz ◽  
Filipe Manuel Clemente
Keyword(s):  
Body Mass ◽  
High Speed ◽  
Team Sport ◽  
Soccer Players ◽  
Reference Standard ◽  
Low Speed ◽  
Total Distance ◽  
Typical Error ◽  
Very High ◽  
Error Of Measurement

This study aimed to investigate the accuracy and reliability of Polar Team Pro GPS units (10 Hz) when used to measure distance and total distance covered in different speed zones. Eight amateur soccer players (age: 21.37 ± 1.40 years, height: 176.75 ± 5 cm, body mass: 176.75 ± 9.47 kg) completed a team sport simulation cycle. Two Polar Team Pro GPS units were positioned on each player’s chest, and one GPSports GPS unit (15 Hz) was positioned between the scapulae. The data obtained from the two Polar Team Pro GPS units were compared to determine inter-unit reliability. The data obtained from one of the Polar Team Pro GPS units and the GPSports GPS unit (reference standard) were compared to determine concurrent accuracy. There was acceptable inter-unit reliability of Polar Team Pro GPS units for total distance (TD), low speed running (LSR) (0.00–13.99 km h−1), high speed running (HSR) (14.00–19.99 km h−1) and very high speed running (VHSR) (>20.0 km h−1) with high ICCs (0.63, 0.99, 0.99 and 0.99, respectively), and low typical error of measurement (%) (TEM%) (4.64, 5.05, 1.06 and 2.89, respectively). Regarding accuracy, the ICCs were extremely high for LSR and HSR (0.99 and 0.92, respectively), but high for TD and VHSR (0.63 and 0.65, respectively). Moreover, TEM (%) values were very low for TD and LSR (0.6 and 1.6, respectively), but they were high for HSR and VHSR (13.8 and 13.1, respectively). Consequently, acceptable inter-unit reliability was observed, indicating that the Polar Team Pro GPS unit is suitable for tracking pertinent team-sport variables. Moreover, the Polar Team Pro GPS units (10 Hz) are accurate under the same conditions. However, the research showed that the two systems cannot be used interchangeably for quantifying distances covered at higher speeds.

scholarly journals Speed increasing scheme by using 3000v dc power supply for low-speed Maglev

2018 ◽  
Vol 4 (3) ◽  
pp. 102-116
Author(s):  
Xiaohua Wang ◽  
Yu Jin ◽  
Ying Lin ◽  
Diqiang Lu ◽  
Feng Qin
Keyword(s):  
Induction Motor ◽  
Power Supply ◽  
Maximum Speed ◽  
Railway Transportation ◽  
Running Speed ◽  
Linear Induction ◽  
Low Speed ◽  
Linear Induction Motor ◽  
Dc Power ◽  
Dc Power Supply

Background: Low-speed maglev is usually designed to run at a maximum speed of about 100~110 km/h, the system does not have any advantage to the traditional urban railway transportation system at the aspect of running speed. Aim: Increase the speed of low-speed Maglev is an urgent task for future promotion. Methods: This paper presents a speed increasing scheme by using 3000 V DC power supply instead of original 1500 V DC. Results: Under this condition, the max output voltage of propulsion inverter could be doubled. For reason that the insulation of linear induction motor has enough margin, only small adjustment of motor is needed to adapt the doubled voltage. Conclusion: To calculate the performance of low-speed maglev while using 3000 V DC, a T-model circuit of single-sided linear induction motor is built, and the result shows that the maximum running speed could be increased to over 160 km/h. This scheme provides a promising way for speed increasing, and it’s a simple and economical approach to enhance the competitiveness of low-speed maglev.

Acute, chronic and acute/chronic ratio between starters and non-starters professional soccer players across a competitive season

2021 ◽  
pp. 175433712110165
Author(s):  
Hadi Nobari ◽  
Daniel Castillo ◽  
Filipe Manuel Clemente ◽  
Jorge Carlos-Vivas ◽  
Jorge Pérez-Gómez
Keyword(s):  
High Speed ◽  
The Body ◽  
Training Load ◽  
Soccer Players ◽  
Physical Conditioning ◽  
Strength And Conditioning ◽  
Total Distance ◽  
Professional Soccer ◽  
Competitive Season ◽  
Body Load

Quantifying the external training load across the season related to the starting status of players could be relevant for physical conditioning staff, since one of the main goals is to apply the adequate individual training load. Thus, the aims of this study were to (1) monitor the acute workload (wAW), chronic workload (wCW), and acute/chronic workload ratio (wACWR) on a weekly basis using the body load (BL) in starter and non-starter professional soccer players; and (2) analyze the differences between starters and non-starters for wAW, wCW, and wACWR using BL, and (3) analyze the weekly average of distance and sprint variables during four periods of the season (pre-, early-, mid-, and end-season). Twenty-one professional soccer players (28.3 ± 3.8 years; 181.2 ± 7.0 cm; 74.4 ± 7.7 kg) belonging to the same team competing in the Iranian Persian Gulf Pro League were evaluated for a period of 48 weeks (one soccer season). The season was divided into pre-season (weeks 1–5), early-season (weeks 6–19), mid-season (weeks 20–35), and end-season (weeks 36–48). Players were classified according to their starting status: players who were in the starting line-up (i.e. starters) and players who did not make the starting line-up (i.e. non-starters). The results showed greater weekly wAW and wCW for starters compared to non-starters during the mid-season (wAW: p = 0.008, g = −1.24; wCW: p = 0.006; g = −1.31) and end-season (wAW: p = 0.001, g = −1.66; wCW: p = 0.001; g = −1.62). Starters also showed greater weekly total distance (wTD), sprint total distance (wSTD), high-speed running distance (wHSRd), and repeated sprints compared with non-starters across all four periods ( p < 0.05; g = −1.36 to −4.95), higher wHSRd/wTD during pre-season ( p = 0.007, g = −1.28) and mid-season ( p = 0.001, g = −1.62) and a greater wSTD/wTD during pre-season ( p = 0.029, g = −0.99). Based on these findings, coaches and strength and conditioning specialists should individualize training according to match exposure throughout a competitive season.

Factors Affecting Classification of Road Segments into High- and Low-Speed Collision Regimes

2017 ◽  
Vol 2659 (1) ◽  
pp. 98-105
Author(s):  
Suliman Gargoum ◽  
Yang Li ◽  
Karim El-Basyouny ◽  
Amy Kim
Keyword(s):  
High Speed ◽  
Site Classification ◽  
Heavy Vehicles ◽  
Factors Affecting ◽  
Low Speed ◽  
High Speeds ◽  
Using Data ◽  
High Level ◽  
A Site

The safety of locations operating under high-speed conditions could significantly differ from that of locations operating under low-speed conditions. Therefore, different approaches must be adopted when speed and safety are analyzed and managed at locations operating under different regimes. However, it is necessary first to understand the factors affecting the speed–collision classification of a site. Locations operating under high speeds are typically expected to have more collisions compared with locations in which speeds are low. Some locations, however, might experience a high collision rate even when speeds are low, or vice versa. This study aimed to identify the factors that affected the site classification into any of those categories by using data collected on roads in Edmonton, Alberta, Canada. Locations were divided into four speed–collision bins (high collision, high speed; high collision, low speed; low collision, high speed; low collision, low speed), and geographic information system maps of locations were produced to explore the spatial distribution of those locations. Moreover, logistic regression was used to understand the role of different factors in identifying the speed–collision bin to which a certain location belonged. The results reveal that locations with high collision rates but low speeds have a relatively high population of heavy vehicles and trucks as well as high speed variability. As for locations with low collision rates and high speeds, these sites were found to have a high level of protection through the presence of medians and shoulders with relatively low access density.

scholarly journals Measurement Uncertainties Analysis in the Determination of Adiabatic Film Cooling Effectiveness by Using Pressure Sensitive Paint (PSP) Technique

2014 ◽  
Author(s):  
Blake Everett Johnson ◽  
Hui Hu
Keyword(s):  
Detailed Analysis ◽  
Film Cooling ◽  
High Speed ◽  
Sampling Rate ◽  
Pressure Sensitive Paint ◽  
Cooling Effectiveness ◽  
Total Uncertainty ◽  
Film Cooling Effectiveness ◽  
Low Speed ◽  
Pressure Sensitive

Pressure sensitive paint (PSP) is useful for measurements of wall pressure in high speed flows, but can be used in an alternative manner in low-speed flows as a gas species concentration detector. Film cooling technology studies have been greatly aided by this use of PSP through use of a mass transfer analogy to determine the adiabatic film cooling effectiveness. The PSP technique allows measurements that have high spatial resolution at high enough sampling rate that a good statistical mean can be determined rapidly. Due to the potential of this technique to deliver high quality adiabatic effectiveness measurements, a detailed analysis of its associated uncertainty is presented herein. In this study, an ambient temperature low speed wind tunnel drives air as the main flow while carbon dioxide (CO2, DR=1.5) is used as the “coolant” gas, though the experiments are done under isothermal conditions. A detailed analysis of the technique is performed here with focus on the measurement uncertainty and process uncertainty for a film cooling study using an array of five cylindrical holes spaced across the span of a flat test plate at a spacing of three diameters center-to-center. The final analysis indicates that the total uncertainty depends strongly on the local behavior of the coolant, with near-field uncertainty as high as 5% at isolated points. In the far-field, the total uncertainty is more uniform throughout the measurement domain and generally lower, at about 3%.

Do You Name Speedy Objects Faster Than Slow Objects: SPEEDED NAMING OR NAMING SPEED? THE AUTOMATIC EFFECT OF OBJECT SPEED ON PERFORMANCE

2018 ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Eran Chajut ◽  
Ran Hassin ◽  
Daniel Algom
Keyword(s):  
High Speed ◽  
Mental Representations ◽  
Reading Aloud ◽  
Naming Task ◽  
Naming Speed ◽  
Low Speed ◽  
Everyday Objects ◽  
Pictures And Words

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects despite the fact that object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

Do elite soccer players cover longer distance when losing? Differences between attackers and defenders

2020 ◽  
pp. 174795412098227
Author(s):  
Carlos Lago-Peñas ◽  
Anton Kalén ◽  
Miguel Lorenzo-Martinez ◽  
Roberto López-Del Campo ◽  
Ricardo Resta ◽  
...  
Keyword(s):  
New York ◽  
High Speed ◽  
Large Scale ◽  
Tracking System ◽  
Soccer Players ◽  
Running Performance ◽  
Situational Variables ◽  
Total Distance ◽  
Professional Soccer ◽  
Score Line

This study aimed to evaluate the effects playing position, match location (home or away), quality of opposition (strong or weak), effective playing time (total time minus stoppages), and score-line on physical match performance in professional soccer players using a large-scale analysis. A total of 10,739 individual match observations of outfield players competing in the Spanish La Liga during the 2018–2019 season were recorded using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions (central defenders, players = 94; external defenders, players = 82; central midfielders, players = 101; external midfielders, players = 72; and forwards, players = 67) and the following match running performance categories were considered: total distance covered, low-speed running (LSR) distance (0–14 km · h−1), medium-speed running (MSR) distance (14–21 km · h−1), high-speed running (HSR) distance (>21 km · h−1), very HSR (VHSR) distance (21–24 km · h−1), sprint distance (>24 km · h−1) Overall, match running performance was highly dependent on situational variables, especially the score-line condition (winning, drawing, losing). Moreover, the score-line affected players running performance differently depending on their playing position. Losing status increased the total distance and the distance covered at MSR, HSR, VHSR and Sprint by defenders, while attacking players showed the opposite trend. These findings may help coaches and managers to better understand the effects of situational variables on physical performance in La Liga and could be used to develop a model for predicting the physical activity profile in competition.

scholarly journals Splatters and Aerosols Contamination in Dental Aerosol Generating Procedures

2021 ◽  
Vol 11 (4) ◽  
pp. 1914
Author(s):  
Pingping Han ◽  
Honghui Li ◽  
Laurence J. Walsh ◽  
Sašo Ivanovski
Keyword(s):  
Particle Size ◽  
Disease Transmission ◽  
High Speed ◽  
Low Speed ◽  
Dental Procedures ◽  
Dental Equipment ◽  
Produce Contamination ◽  
Fluorescein Dye ◽  
Filter Papers ◽  
Airborne Disease

Dental aerosol-generating procedures produce a large amount of splatters and aerosols that create a major concern for airborne disease transmission, such as COVID-19. This study established a method to visualise splatter and aerosol contamination by common dental instrumentation, namely ultrasonic scaling, air-water spray, high-speed and low-speed handpieces. Mock dental procedures were performed on a mannequin model, containing teeth in a typodont and a phantom head, using irrigation water containing fluorescein dye as a tracer. Filter papers were placed in 10 different locations to collect splatters and aerosols, at distances ranging from 20 to 120 cm from the source. All four types of dental equipment produced contamination from splatters and aerosols. At 120 cm away from the source, the high-speed handpiece generated the greatest amount and size (656 ± 551 μm) of splatter particles, while the triplex syringe generated the largest amount of aerosols (particle size: 1.73 ± 2.23 μm). Of note, the low-speed handpiece produced the least amount and size (260 ± 142 μm) of splatter particles and the least amount of aerosols (particle size: 4.47 ± 5.92 μm) at 120 cm. All four dental AGPs produce contamination from droplets and aerosols, with different patterns of distribution. This simple model provides a method to test various preventive strategies to reduce risks from splatter and aerosols.

scholarly journals Exercise Intensity and Technical Involvement in U9 Team Handball: Effect of Game Format

2021 ◽  
Vol 18 (11) ◽  
pp. 5663
Author(s):  
Georgios Ermidis ◽  
Rasmus C. Ellegard ◽  
Vincenzo Rago ◽  
Morten B. Randers ◽  
Peter Krustrup ◽  
...  
Keyword(s):  
Heart Rate ◽  
Locomotor Activity ◽  
Exercise Intensity ◽  
High Intensity ◽  
High Speed ◽  
Medium Size ◽  
Total Distance ◽  
Team Handball ◽  
Large Size ◽  
Game Format

The purpose of this study was to quantify the exercise intensity and technical involvement of U9 boys’ and girls’ team handball during different game formats, and the differences between genders. Locomotor activity (total distance, distance in speed zones, accelerations, and decelerations), heart rate (HR), and technical involvement (shots, goals, and duels) metrics were collected during various 15 min game formats from a total of 57 Danish U9 players (37 boys and 20 girls). Game formats were a small size pitch (20 × 13 m) with 3 vs 3 players and offensive goalkeepers (S3 + 1) and 4 vs 4 players (S4), a medium size pitch (25.8 × 20 m) with 4 vs 4 (M4) and 5 vs 5 (M5) players, and a large size pitch (40 × 20 m) with 5 vs 5 (L5) players. Boys and girls covered a higher total distance (TD) of high-speed running (HSR) and sprinting during L5 games compared to all other game formats (p < 0.05; ES = (−0.9 to −2.1), (−1.4 to −2.8), and (−0.9 to −1.3) respectively). Players covered the highest amount of sprinting distance in L5 games compared to all other game formats (p < 0.01; ES = 0.8 to 1.4). In all the game formats, players spent from 3.04 to 5.96 min in 180–200 bpm and 0.03 min to 0.85 min in >200 bpm of the total 15 min. In addition, both genders had more shots in S3 + 1 than M5 (p < 0.01; ES = 1.0 (0.4;1.7)) and L5 (p < 0.01; ES = 1.1 (0.6;2.2)). Team handball matches have high heart rates, total distances covered, and high-intensity running distances for U9 boys and girls irrespective of the game format. Locomotor demands appeared to be even higher when playing on larger pitches, whereas the smaller pitch size and fewer players led to elevated technical involvement.

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