The assessment of the match performance of association football referees: Identification of key variables.

The purpose of this study was to understand the contribution of each performance indicator to evaluate match performance of football referees. Thirty-four elite Referee Match Observers (RMOs) from the Portuguese FA participated voluntarily in the study. From the official assessment sheet of each game, the referee's game score was categorized in two groups according to referee's game score: i) Referees with a Low Score (LFS) and ii) Referees with High Score (HFS). A multivariable binary logistic regression model was used to assess the relationship between the Performance Indicators (PIs) of the dimensions i) game difficulty and game intervention and ii) disciplinary actions and game management in relation to the referee's match assessment score. The model proposed revealed that only the PIs negative application of the laws of the game and referee teamwork, from the dimension disciplinary actions and game management, significantly defined the final game referee's assessment score. This study suggests that the PIs scored by the RMOs contributed in a different way to the referee's game score. The model explains 60.4% of the referee's game score based on the variables referee teamwork and negative application of the laws of the game.

The Use of Wearable Technologies in the Assessment of Physical Activity in Preschool- and School-Age Youth: Systematic Review.

In recent years, physical activity assessment has increasingly relied on wearable monitors to provide measures for surveillance, intervention, and epidemiological research. This present systematic review aimed to examine the current research about the utilization of wearable technology in the evaluation in physical activities of preschool- and school-age children. A database search (Web of Science, PubMed and Scopus) for original research articles was performed. A total of twenty-one articles met the inclusion criteria, and the Cochrane risk of bias tool was used. Wearable technology can actually be a very important instrument/tool to detect the movements and monitor the physical activity of children and adolescents. The results revealed that there are a few studies on the influence of these technologies on physical activity in schools, and most of them are descriptive. In line with previous research, the wearable devices can be used as a motivational tool to improve PA behaviors and in the evaluation of PA interventions. However, the different reliability levels of the different devices used in the studies can compromise the analysis and understanding of the results.

Can Tracking Data Help in Assessing Interpersonal Contact Exposure in Team Sports during the COVID-19 Pandemic?

During the COVID-19 pandemic, the temporary closure of physical activity and sports facilities, and the generalized cancellation or postponement of sports events have a massive impact on social and economic development. In this study, we explored the feasibility of using tracking data from a football match to assess interpersonal contact between individuals by calculating two measures of respiratory exposure. The dynamic tracking positioning of all players and referees during one international football match was analyzed. For each individual, two measures of respiratory exposure were calculated, based on the 2 m interpersonal distance recommendations for contact tracing for COVID-19 control. Overall, individuals spent a median of 0.12 mm:ss (IQR = 0.45 mm:ss) exposed to interpersonal contact of fewer than 2 m from others. The highest value of exposure was observed between two players of opposing teams (6.35 mm:ss). The results suggest that tracking data can be used to assess respiratory exposure to interpersonal contact in team sports, such as football. The measures of exposure calculated can be used to the prompt identification of high-risk contacts of COVID-19 cases during a match or a training session, but also the risk stratification of different sports and physical activities.