Team sport is a social context in which individuals are organized into groups or teams which compete to win, cooperate or perform tasks towards a shared goal (Smith, Mellano, & Ullrich-French, 2019). Sports are played for entertainment purposes and can also be used as vehicles for enhancing physical and cognitive development.
Team sports are regulated to an extensive extent by leagues and the rules of the game, limiting the amount of practice and competition a team can undertake. For example, the National Collegiate Athletic Association stipulates a maximum number of scholarships for intercollegiate athletic teams and regulations on how many games they can play in a season. The governing bodies for professional sports, such as the Premier League, also govern competition characteristics and the number of players per team.
There are many team sports to choose from, including soccer, American football, ice hockey, basketball and tennis. Each sport is unique in its rules, playing dimensions and player density.
Tracking systems are increasingly common in most sports, providing practitioners with a large quantity of data on the performance of athletes. This data is a rich resource for practitioners to use when assessing athlete fitness, training adaptations and injury risk reduction strategies [2, 3, 11, 40].
One of the most obvious applications of tracking is in monitoring external load during training, including pre-match preparation and competition. In addition to monitoring external load, the data can provide insights into the specificity of planned training, by identifying when players are subjected to a greater or lesser volume and intensity than planned.
For example, in Australian football, where the game is based on a series of fifteen-minute quarters with stoppages and commercial breaks, performance staff plan the external load for desired training adaptations and responses to match pressure (Fig. 3). They also consider the days between matches and how external load will vary over the microcycle. This can influence the choice of training goals within a cycle (Fig. 4) to ensure balance in physical preparation and readiness for competition, reducing the likelihood of injuries.
Athletes are often tracked for several hours during a match, with a large proportion of their performance being determined by their ability to react quickly and effectively to the actions of their opponents. This data is a valuable resource to understand the impact of tactical decisions on physical performance, for example, by measuring the changes in speed of players during the game, which may lead to greater or less force in the collisions between athletes.
Various metrics from tracking systems are commonly reported by practitioners in team sports, although the selection of the most appropriate metrics is important for ensuring the data is relevant to the context of a particular sport. The most popular metrics include distance covered at different speeds and the occurrence of high-speed movement, accelerations and decelerations, all of which can be measured from an accelerometer or gyroscope. However, this is not sufficient to provide meaningful information in all team sports. Given the complexity of a sport and its constraints, it is important to select the most appropriate metrics for the analysis of athlete performance in that context.