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ENERGY EXPENDITURE AND INTENSITY OF PHYSICAL ACTIVITY IN SOCCER REFEREES DURING MATCH-PLAY  [cached]
Alberto Inácio da Silva,Luiz Cláudio Fernandes,Ricardo Fernandez
Journal of Sports Science and Medicine , 2008,
Abstract: The aim of this study was to determine the caloric expenditure and the intensity of physical activities performed by official soccer referees during a match expressed in Metabolic Equivalent (METs). The physical activity of referees accredited by CBF (Brazilian Confederation of Soccer) was video-recorded during twenty-nine official games of Paraná Championship (Brasil), Series A and B of the 2005/2006. Computerized video analysis was used to determine the time spent in 6 locomotor activities (standing still, walking, jogging, backwards running, running and sprint). The frequency and duration of each activity were recorded and these data were utilized to calculate the distance covered by the referee. Energy expenditure values were estimated, utilizing specific equations, from the time players spent in each motor activity. The referees observed in this study had a mean age of 38.9 ± 3.8 years, body mass of 86.1 ± 7.1 kg, stature of 1.80 ± 0.07 m and a body mass index of 26.5 ± 0.6 kg·m-2. During match-play, referees covered an average distance of 9155.4 ± 70.3 meters (8411 - 9765), with a mean energy expenditure of 734.7 ± 65 kcal. This energy expenditure was significantly reduced in the second half: 359.9 ± 6.3 vs 374.7 ± 6.6 kcal (p = 0.006), and averaged to be moderate energy intensity (5 METs) with predominant utilization of the aerobic energy system. In total, during 67% of match-play the intensity was equal or lower than 3.8 METs and in 33% it was higher than 9.8 METs. The pattern of movement observed in the present study confirms that soccer refereeing may be considered as a highly intermittent exercise mode. The high to low-intensity activity ratio may be defined as 1:7.1. In conclusion, referees officiating in professional soccer matches in Brazil should perform a physical conditioning regime that provides the stamina required at this level and consume appropriate and adequate nutrition to meet the energetic demands for match-play
Intensity of real competitive soccer matches and differences among player positions
Coelho, Daniel Barbosa;Mortimer, Lucas ávila;Condessa, Luciano Antonacci;Morandi, Rodrigo Figueiredo;Oliveira, Bernardo Moreira;Marins, Jo?o Carlos Bouzas;Soares, Danusa Dias;Garcia, Emerson Silami;
Revista Brasileira de Cineantropometria & Desempenho Humano , 2011, DOI: 10.5007/1980-0037.2011v13n5p341
Abstract: most investigations on soccer match intensity have evaluated friendly, simulated or a small number of games on a recreational basis or including a small number of players. there are no studies investigating real competitive situations including a considerable number of athletes and games or differences among player positions using heart rate as an intensity parameter. the aim of this study was to determine brazilian soccer game intensity (gi) during official competitive matches and to compare gi among different player positions. heart rate (hr) was measured in 26 under-17 (u-17) and 18 under-20 (u-20) soccer players (age 16.38 ± 0.5 and 18.24 ± 0.66 years, respectively) during 14 and 15 official games, respectively. individual maximal heart rate (hrmax) and anaerobic threshold (at) hr were evaluated in field tests. gi defined as %hrmax was monitored considering five intensity zones ranging from 1 = < 70% hrmax to 5 = 95-100% hrmax. mean gi and at intensity were 84.4 ± 5.1 and 86.3 ± 4.0% hrmax for the u-17 category and 84.1 ± 4.1 and 87.0 ± 5.1% hrmax for the u-20 category, respectively. wingbacks (wb) spent more time in zone 5 than forwards (fw) (p<0.05). midfielders (mf) spent more time in zone 3 than all other players and in zone 4 than defenders and fw (p<0.05). mean gi and at intensity were similar. wb performed more maximum effort than fw. mf did not participate as much in maximum effort as did wb and fw.
Intensity of real competitive soccer matches and differences among player positions. DOI: 10.5007/1980-0037.2011v13n5p341
Daniel Barbosa Coelho,Lucas ávila Mortimer,Luciano Antonacci Condessa,Rodrigo Figueiredo Morandi
Revista Brasileira de Cineantropometria e Desempenho Humano , 2011,
Abstract: Most investigations on soccer match intensity have evaluated friendly, simulated or a small number of games on a recreational basis or including a small number of players. There are no studies investigating real competitive situations including a considerable number of athletes and games or differences among player positions using heart rate as an intensity parameter. The aim of this study was to determine Brazilian soccer game intensity (GI) during official competitive matches and to compare GI among different player positions. Heart rate (HR) was measured in 26 under-17 (U-17) and 18 under-20 (U-20) soccer players (age 16.38 ± 0.5 and 18.24 ± 0.66 years, respectively) during 14 and 15 official games, respectively. Individual maximal heart rate (HRmax) and anaerobic threshold (AT) HR were evaluated in field tests. GI defined as %HRmax was monitored considering five intensity zones ranging from 1 = < 70% HRmax to 5 = 95-100% HRmax. Mean GI and AT intensity were 84.4 ± 5.1 and 86.3 ± 4.0% HRmax for the U-17 category and 84.1 ± 4.1 and 87.0 ± 5.1% HRmax for the U-20 category, respectively. Wingbacks (WB) spent more time in zone 5 than forwards (FW) (p<0.05). Midfielders (MF) spent more time in zone 3 than all other players and in zone 4 than defenders and FW (p<0.05). Mean GI and AT intensity were similar. WB performed more maximum effort than FW. MF did not participate as much in maximum effort as did WB and FW.
METABOLIC DEMANDS OF MATCH PERFORMANCE IN YOUNG SOCCER PLAYERS  [cached]
Alper Aslan,Caner A??kada,Alpay Güven?,Hasan G?ren
Journal of Sports Science and Medicine , 2012,
Abstract: The aim of the present study was to determine metabolic responses, movement patterns and distance covered at running speeds corresponding to fixed blood lactate concentrations (FBLs) in young soccer players during a match play. A further aim of the study was to evaluate the relationships between FBLs, maximal oxygen consumption (VO2max) and distance covered during a game. A multistage field test was administered to 32 players to determine FBLs and VO2max. Blood lactate (LA), heart rate (HR) and rate of perceived exertion (RPE) responses were obtained from 36 players during tournament matches filmed using six fixed cameras. Images were transferred to a computer, for calibration and synchronization. In all players, values for LA and HR were higher and RPE lower during the 1st half compared to the 2nd half of the matches (p < 0.01). Players in forward positions had higher LA levels than defenders, but HR and RPE values were similar between playing positions. Total distance and distance covered in jogging, low-moderate-high intensity running and low intensity sprint were higher during the 1st half (p < 0.01). In the 1st half, players also ran longer distances at FBLs [p<0.01; average running speed at 2mmol·L-1 (FBL2): 3.32 ± 0.31m·s-1 and average running speed at 4mmol·L-1 (FBL4): 3.91 ± 0.25m·s-1]. There was a significant difference between playing positions in distance covered at different running speeds (p < 0.05). However, when distance covered was expressed as FBLs, the players ran similar distances. In addition, relationships between FBLs and total distance covered were significant (r = 0.482 to 0.570; p < 0.01). In conclusion, these findings demonstrated that young soccer players experienced higher internal load during the 1st half of a game compared to the 2nd half. Furthermore, although movement patterns of players differed between playing positions, all players experienced a similar physiological stress throughout the game. Finally, total distance covered was associated to fixed blood lactate concentrations during play
DEHYDRATION IN SOCCER PLAYERS AFTER A MATCH IN THE HEAT
A.P.M. Guttierres,A.J. Natali,J.M. Vianna,V.M. Reis
Biology of Sport , 2011,
Abstract: We investigated the level of dehydration after a match in 20 soccer players (mean ± SD, 17.9 ± 1.3 years old, height 1.75 ± 0.05 m, body mass 70.71± 7.65 kg) from two teams that participate in a Brazilian Championship game performed at a temperature of 29 ± 1.1 C and a relative humidity of 64 ± 4.2%. Body mass, urine specific gravity and urinary protein were measured before and after the match, and self-perception measurements were performed during the match. Body mass loss was 1.00 ± 0.39 kg, corresponding to a dehydration percentage of 1.35 ± 0.87%. The mean sweating rate during the match was 866 ± 319 ml · h[sup]-1[/sup] and total fluid intake was 1265.00 ± 505.45 ml. The sweating rate and the quantity of ingested fluids correlated positively (r = 0.98; P<0.05). Protein occurred in the urine in 18 soccer players. The players showed no perception of thirst and considered themselves as comfortable during the match. At the end of the match the soccer players replaced 57.7 ± 15% of the water loss and presented a condition of significant to severe dehydration based on the post-match urine specific gravity data (1.027 ± 6 g · ml[sup]-1[/sup]). The results of this study demonstrate that most of the soccer players began the match with some degree of dehydration that worsened during the match.
AMIC Cartilage Repair in a Professional Soccer Player
S. Bark,H. Riepenhof,J. Gille
Case Reports in Orthopedics , 2012, DOI: 10.1155/2012/364342
Abstract: We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm2), an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003). After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months.
AMIC Cartilage Repair in a Professional Soccer Player  [PDF]
S. Bark,H. Riepenhof,J. Gille
Case Reports in Orthopedics , 2012, DOI: 10.1155/2012/364342
Abstract: We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3?cm2), an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003). After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months. 1. Introduction Articular cartilage defects are one of the most common causes of permanent disability in athletes. Excessive stress on a joint with an articular cartilage defect may accelerate further degenerative changes and predispose the athlete to a higher risk of osteoarthritis. Athletes require an articulating cartilage surface that can withstand the high mechanical joint stresses generated during their specific sports activity. Treatment of an athlete with articular cartilage damage is consequently a significant challenge to healthcare professionals. We report a case of a professional soccer player suffering from a traumatic cartilage lesion treated with an enhanced microfracture technique (AMIC). 2. Case Report A 28-year-old professional soccer player suffered an anterior cruciate ligament tear after a tackling in a soccer game. He underwent a routine anterior cruciate ligament reconstruction with use of quadruple hamstring autograft and bioabsorbable fixation of the implants. He recovered well and returned to competition after 6 months. Another 2 month later he injured his knee hitting the ground with the lateral side of the knee. He referred immediately discomfort but no apparent effusion and he continued to play on. After one week, the discomfort progressed despite physiotherapy. An orthopaedic assessment was made for persistent pain located at the lateral aspect of the knee. At that time the treating surgeon performed a diagnostic arthroscopy and it was confirmed that the patient had a cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle (Figure 1). He was referred to the authors
Design and Development of a Comprehensive Omni Directional Soccer Player Robot
Hooman Aghaebrahimi Samani,Amir Abdollahi,Hossein Ostadi,Saeed Ziaee Rad
International Journal of Advanced Robotic Systems , 2008,
Abstract: Omni directional mobile robots have been popularly employed in several applications especially in soccer player robots considered in Robocup competitions. However, omni directional navigation system, omni-vision system and omni-kick mechanism in such soccer player robots have not ever been combined. This situation brings the idea of a robot with no head direction into existence, i.e. a comprehensive omni directional soccer player robot. Such a robot can respond more quickly and it would be capable for more sophisticated behaviors such as ball passing or goal keeping. This paper has tried to focus on description of areas such as omni directional mechanisms, mechanical structure, control, optimized odometry system, omni-vision sensor for self localization and other subjects related to soccer player robot's software.
How does the past of a soccer match influence its future?  [PDF]
Andreas Heuer,Oliver Rubner
Physics , 2012,
Abstract: Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals can be described by a constant goal rate for each team, implying simple Poissonian and Markovian behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. The analysis scheme is applied to approximately 40 seasons of the German Bundesliga. It is possible to characterize the impact of the previous course of the match on the present match behavior. This allows one to identify interesting generic features about soccer matches and thus to learn about the hidden complexities behind scoring goals.
Genetic Programming Method of Evolving the Robotic Soccer Player Strategies with Ant Intelligence
R. Geetha Ramani,R. Subramanian,P. Viswanath
International Journal of Advanced Robotic Systems , 2009,
Abstract: This paper presents the evolved soccer player strategies with ant-intelligence through genetic programming. To evolve the code for players we used the Evolutionary Computation tool (ECJ simulatorEvolutionary Compuation in Java). We tested the evolved player strategies with already existing teams in soccerbots of teambots. This paper presents brief information regarding learning methods and ant behaviors. Experimental results depicts the performance of the evolved player strategies.
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