# Relationship between Physical Factors and Change of Direction Speed in Team Sports
## 1 Introduction  
Historically, agility was characterized as a unique entity consisting of isolated preplanned movements. More recently, agility is predefined as a rapid whole-body movement with change of velocity or direction in response to a stimulus [1]. It comprises two key components: speed in changing direction, and perceptual and decision-making factors [2]. In this definition, the cognitive component that determines the agility performance applies to open skills only. A change of direction task that is preplanned has been described as a change of direction speed, and this phrase has become increasingly common in distinguishing this closed skill from agility involving a reaction [3, 4]. However, a high level of agility performance is not strongly dependent just on acceleration and sprinting speed, but also on the ability to coordinate movement and react to visual cues of the opponents to provide a quick and appropriate response [1]. The most current model divides agility into cognitive, physical, and technical components [5], instead of the perceptual components of decision-making and change of direction speed [2]. Agility is an essential component in most field and team sports, combat sports, and court sports. Athletes are required to accelerate, decelerate, and change direction throughout the game. They need the ability to quickly change direction and place themselves in a good position to execute with required speed and accuracy [6]. This recognizes that players do not randomly change velocity or direction, but their movements are oftenin response to cues such as the movements of a ball or the actions of opposing players. Therefore, agility performance is important, especially for players of team sports. However, a large number of agility tests do not include executing a change of direction while reacting to an external stimulus and cognitive component. Although these perceptual and cognitive considerations likely need to be included in a true agility test, most of them actually concern only change of direction speed [7,8]. Change of direction speed (CODS) ability can be described as a movement where no immediate reaction to a stimulus is required, and it is considered pre-planned in nature [1]. Therefore, the phrase \"reactive agility\" has been introduced to differentiate the tests with or without response to a stimulus [5]. To the best of our knowledge, there have only been a few studies in which an agility test was used that included the cognitive component [9, 10, 11, 12]. The CODS tests are more common, and their structure has been well investigated [1,2,5]. In these structures, the CODS was in-turn determined by technical factors such as stride adjustments, physical elements such as straight sprinting speed, and leg-muscle qualities, which include strength, power, and reactive strength. However, we have found many contradictory results in this area. Not all studies confirmed the relationship between sprint speed, jump and strength parameters, and the time in CODS [13, 14, 15, 16, 17, 18]. In these cases, the authors assumed that if an athlete performed well during one test, he might perform well in another test. Therefore, this review is focused on the relationship between CODS and factors of physical fitness like sprint speed, jump ability, and muscle strength. For example, CODS performance includes many linear sprint sections. However, one of the major limitations associated with many CODS tests is that they tend to feature a relatively large amount of linear sprinting, and this has a substantial influence on the total time of the assessment. Furthermore, players must find the best possible position to shoot while avoiding opponents in the game, and it is rare to see them running for a longer distance without cutting. Therefore, we assumed that the strength of the relationship between linear speed and CODS can be affected by the type of CODS test or sprint distance. Furthermore, it was documented that explosive strength training with vertical jump exercises improves CODS performance [19].