Lights, cameras, and reactive agility

Agility lacks a precise definition (Holmberg, 2009; Jeffreys, 2011; Sheppard & Young, 2006). Agility has been defined as the ability to change directions efficiently or with a minimal loss of control or speed (Barnes, Schilling, Falvo, Weiss, Creasy, & Fry, 2007; Safaric & Bird, 2011; Young & Wiley, 2009); agility requires the ability to brake, change direction, and accelerate again (Plisk, 2000). Agility also has been defined as basic movements that result in sudden changes in body direction in combination with rapid movement of the limbs (Farrow, Young, & Bruce, 2005); described as a rapid, whole-body change of direction or speed in response to a stimulus (Sheppard & Young, 2011); and described as the coupling of deceleration with a reactive acceleration (Plisk, 2000).

More recently, agility has been divided into two categories: reactive agility and planned agility (Oliver & Meyers, 2009; Safaric & Bird, 2011; Young & Wiley, 2009). Planned agility involves a closed skill where movements are known ahead of time (Oliver & Meyers, 2009). Reactive agility is an open skill that captures the perceptual and decision-making skills required within a game context (Jeffreys, 2011; Serpell, Young, & Ford, 2011).

Recently, numerous tests involving the use of flashing lights to simulate a reactive condition have been used. According to N.C. State University’s Bob Alejo, the NBA combine tests now have a reactive agility test that incorporates a flashing light. The question, then, is whether or not these agility tests with flashing lights measure something different than a traditional agility test [Note: the test below with John Wall is not the one used at the NBA combine, as far as I know, but is an example of light-based testing].

Oliver and Meyers (2009) examined performance on a planned agility test versus a reactive agility test using a flashing light as the external stimulus. Analyses revealed a high degree of common variance between the two agility protocols (r2 = .87). This suggested that while the times were slower in the reactive test than the planned test, the two tests measured the same predominantly physical qualities. In essence, the planned agility test and the reactive agility test were the same test with a slightly different procedure.

Farrow, Young, and Bruce (2005) examined performance on a planned agility test versus a reactive agility test using a video display as the external stimulus. In this test, the r2 =.49; the two tests shared approximately 50% of the common variance. This suggested that the planned and reactive agility tests were measuring similar, but distinct abilities.

Furthermore, Farrow et al. (2005) demonstrated that the reactive agility test differentiated between groups of low, intermediate, and high skilled players. Farrow et al. noted, “The highly-skilled players’ ability to anticipate the intended pass direction, as evidenced by a negative decision-making mean (-149 ms) allowed them to predict earlier their change of direction and hence complete the sprint component of the test with greater speed. In comparison, the lesser-skilled group’s decision times (22 ms) indicated that they waited until the passer presented all available information before initiating their change of direction” (p. 58).

A flashing light does not present these cues which would enable a skilled performer to anticipate and therefore move more quickly, but successful performance in a game is dependent on these cues. The perceptual abilities thought to differentiate expert and non-expert players include pattern recognition and the ability to predict and anticipate an opponent’s behavior (Aglioti, Cesari, Romani, & Urgesi, 2008). Because the distinguishing attributes of expert performers are predominantly domain-specific (Abnernethy, Baker, & Cote, 2005), reactive agility tests should incorporate game-realistic simulations. It is the coupling of perception with action that is crucial to performance (Serpell et al., 2011), and a light cue does not train this coupling, as basketball players do not respond to flashing lights during a game.

Whereas responding to a flashing light may be termed a reactive agility test or drill, this misses the purpose of distinguishing planned agility and reactive agility. Reactive agility is meant to incorporate perceptual factors, and the perceptual demands of reacting to a light stimulus and reacting to a player in a game differ significantly in terms of task demands. Reactive agility tests using a video-based external stimulus have been found to differ from planned agility tests, whereas using a flashing light as the external stimulus tests the same abilities as a planned agility test.

By Brian McCormick, PhD
Director of Coaching, Playmakers Basketball Development League
Author, The 21st Century Basketball Practice

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