Faculty Opinions recommendation of Association of field position and career length with risk of neurodegenerative disease in male former professional soccer players.

Objectives: Many studies have focused on the long-term impact of concussions in professional sports, but few have investigated short-term effects. This study examines concussion effects on individual players in the Major League Soccer (MLS) and English Premier League (EPL) by assessing 1) return-to-play (RTP) time, 2) career length, and 3) performance. Methods: Contracts, transactions, injury reports, and performance statistics from 2008-17 were obtained from the official MLS and EPL online publications. Players who sustained a concussion were compared with the 2008-17 non-concussed player pool. Career length was analyzed using Kaplan-Meier survival curves and athletes were stratified by player age, experience, and longevity. Player performance changes were evaluated between the years before versus after concussion. RTP and games missed were analyzed and compared. Results: Of the 1,784 eligible MLS and 2,001 eligible EPL players evaluated over the 10-year period, 102 MLS players sustained 165 concussions and 124 EPL players sustained 142 concussions resulting in injury protocol initiation. MLS players on average missed 7.5 games after a concussion, with 33.5 days missed, whereas EPL players on average missed 0.5 games after a concussion with 9.5 days missed, which was statistically different (p<0.001, p<0.0001). Performance was reduced at all non-goalie positions for goals and assists post-concussion for players in the MLS and in the EPL (p < 0.01). Concussed MLS players playing non-goalie positions scored 2.5 points/year less following a concussion and played in 20 fewer games/year on average. Concussed EPL players playing non-goalie positions scored 3.1 points/year less following a concussion and started in 5.8 fewer games/year on average. Concussed MLS and EPL goalies saw no significant change in performance, although EPL goalies played 3.2 additional games/year on average (p <0.05). The probability of playing a full season post-concussion was not significantly decreased compared with the non-concussed pool (p > 0.05) in both leagues Conclusion: This study investigating the short-term effects of concussion on professional soccer players demonstrates that performance is reduced for non-goalie players, without a significant difference in career longevity between concussed and non-concussed controls.

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A study on the urine specific gravity before training and sweating response during training of professional soccer players

Exercise Science ◽

10.15857/ksep.2007.16.1.31 ◽

2007 ◽

Vol 16 (1) ◽

pp. 31-38

Author(s):

YoungSoo Lee ◽

Siyoung Kim ◽

Lee sang ho ◽

Sanghyoun Lee

Keyword(s):

Specific Gravity ◽

Soccer Players ◽

Urine Specific Gravity ◽

Professional Soccer

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The relationship between training load and fitness indices over a pre-season in professional soccer players

The Journal of Sports Medicine and Physical Fitness ◽

10.23736/s0022-4707.20.10109-9 ◽

2020 ◽

Vol 60 (3) ◽

Cited By ~ 2

Author(s):

Leonidas Papadakis ◽

Charis Tymvios ◽

Konstantinos Patras

Keyword(s):

Training Load ◽

Soccer Players ◽

Professional Soccer ◽

The Relationship

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Comparison of Official and Friendly Matches through Acceleration, Deceleration and Metabolic Power Measures: A Full-Season Study in Professional Soccer Players

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115980 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5980

Author(s):

Hadi Nobari ◽

Sara Mahmoudzadeh Khalili ◽

Rafael Oliveira ◽

Alfonso Castillo-Rodríguez ◽

Jorge Pérez-Gómez ◽

...

Keyword(s):

Effect Size ◽

Total Duration ◽

Soccer Players ◽

Metabolic Power ◽

Professional Soccer ◽

Premier League ◽

Small Effect Size ◽

Moderate Effect Size ◽

High Effort

Soccer is a popular team sport and highly demanding activity that requires high effort and long-term training plans. The goals of this study were to compare the accelerations, decelerations and metabolic power between official and friendly full matches, between the first and second halves of the matches, and between both halves of official and friendly matches. Twelve professional soccer players (age, 28.6 ± 2.7 years; height, 182.1 ± 8.6 cm; body mass, 75.3 ± 8.2 kg; BMI, 22.6 ± 0.7 kg/m2) participated in this study. A total of 33 official and 10 friendly matches were analyzed from the Iranian Premier League. All matches were monitored using GPSPORTS systems Pty Ltd. The following variables were selected: total duration of the matches, metabolic power, accelerations Zone1 (<2 m·s−2) (AccZ1), accelerations Zone2 (2 to 4 m·s−2) (AccZ2), accelerations Zone3 (>4 m·s−2) (AccZ3), decelerations Zone1 (<−2 m·s−2) (DecZ1), decelerations Zone2 (−2 to −4 m·s−2) (DecZ2) and decelerations Zone3 (>−4 m·s−2) (DecZ3). The major finding was shown in metabolic power, where higher values occurred in friendly matches (p < 0.05 with small effect size). Furthermore, total duration, AccZ3, DecZ1, DecZ2, and DecZ3 were revealed to be higher in official matches, while AccZ1 and AccZ2 were higher in friendly matches. The second half of the official matches revealed higher values for total duration compared to friendly matches (p < 0.05, moderate effect size). In conclusion, this study observed higher values of metabolic power in friendly matches compared to official matches. AccZ3, DecZ1, DecZ2, and DecZ3 were higher in official matches, while AccZ1 and AccZ2 were higher in friendly matches.

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

International Journal of Sports Science & Coaching ◽

10.1177/1747954120982270 ◽

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.

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