What is Agility?
Over the past several decades, ‘agility’ appears to have been referred to as almost anything that requires an athlete to quickly change direction multiple times. As a prime example, the T-test, Illinois agility test, arrowhead agility test, and the pro-agility test have all historically been referred to as agility tests, simply because they require an athlete to complete a pre-planned course of directional changes as quickly as possible. However, it is important to understand from hereinafter these tests are not actually a measure of agility, but instead a measure of ‘change of direction speed’.
Agility has been a topic of large discussion in recent years and has led to several experts attempting to clearly define it. Perhaps the best current definition of agility is that proposed by Sheppard and Young (1):
Agility is ‘‘a rapid whole body movement with change of velocity or direction in response to a stimulus’’.
If anything, the fundamental words to remember in that definition are “in response to a stimulus”. It is this fragment of the definition that separates a “true” agility test, from a simple change of direction speed test (e.g. pro-agility test) – thus, agility contains a reactive component. This reactive component is built-up of many cognitive functions (1) such as:
- Visual processing
- Reaction time
It is the absence of these cognitive functions during traditional agility tests (e.g. t-test) that means they are in fact simply change of direction speed (CODs) tests. The difference between agility and CODs is not just semantics, they are completely different performance qualities which only have a small relationship with one another, if any (2, 3, 4).
For example, a defender’s reaction to an attacker’s sudden movement would be classified as an agility-based movement, as it requires them to make a reactive decision based upon the attacker’s impulsive movement. In contrast, when an athlete is instructed to run through a planned arrangement of cones (e.g. T-test), then the reactive component is removed and it is purely an example of their CODs.
Though agility requires the use of cognitive components, it is also composed of other qualities – namely ‘physical’ and ‘technical’. It is these several qualities (cognitive, physical, and technical) which have been said to collectively form agility (Figure 1). This combination of independent qualities, plus the unplanned nature of agility, means agility has been referred to as a complex and open motor skill in its own right (5).