The concept of agility has seen many changes of definition in the last 60 years. Definitions have appeared in measurement texts (Clarke, 1950; Cureton, 1947; McCloy and Young, 1954) and research studies/ reviews (Chelladurai, 1976; Chelladurai and Yuhasz, 1977; Sheppard and Young, 2006; Young et al., 2001) which describe different elements of agility. In a review of the literature, five key descriptive elements of agility were identified: precision/ accuracy, change of direction, body (parts), quickness/rapidity, and reaction; and none of the 24 definitions found had all five elements. Differences in definition have altered the reliability and validity of tests--designed to quantify agility for the purposes of skill acquisition (Beise and Peaseley, 1937; Mohr and Haverstick, 1956; Rarick, 1937), prediction of athletic success (Gates and Sheffield, 1940; Hoskins, 1934; Johnson, 1934; Larson, 1941; Lehsten, 1948), and possibly even the maintenance of fitness/health (Barnett et al., 2008). As evidence of this discrepancy in the literature, Craig (2004, p. 13) noted a "gap between the applied and the scientific knowledge". This apparent historical miscommunication between practitioners and sport scientists has, at times, resulted in the misclassification or inappropriate application of change of direction speed (CODS) tests. Instead of being its own category of assessment, such CODS tests have been misinterpreted as tests of agility. This knowledge gap may be due, at least in part, to the many different definitions of agility that persists in the literature. Each definition derives from the sub-disciplinary perspective from which the measurement is derived (biomechanics, motor learning, physical education, strength and conditioning, or skill coaching). The definition of agility adopted for the present investigation comes from Sheppard and Young (2006, p.922): "a rapid whole-body movement with changing velocity or direction in response to a stimulus". This definition results in only a few options for testing "true" agility. The majorities of available tests are CODS tests and should be recognized as such in future studies as they test a distinct component, separate from agility. Only movements requiring reaction to a stimulus should be classified as "agility" (Farrow, 2005).
Of the 24 unique definitions, three early researchers included 'reaction' when describing agility (O'Conner and Cureton, 1945; Cureton, 1947; and Clarke, 1950). Unfortunately, these early definitions were not widely adopted. Several CODS tests were developed prior to, and even after, Chelladurai (1976) critiqued prior research for the absence of reaction to a stimulus re: agility and further suggested that the whole body should be in motion, not just a single limb. Chelladurai (1976) also developed an agility classification scheme that included 'simple', 'complex', and 'universal' agility. However, his classification scheme was also limited in that it still classified CODS tests as "simple" agility. Nearly 30 years later, and with no significant change in agility protocols, Sheppard and Young (2006, p. 922) indicated the need for "a simpler definition of agility [that] could be established by using an exclusion criterion, rather than an inclusion criterion". With no acknowledged or standard criteria, tests were published (Draper, 1985; Graham, 2000; Hoffman et al., 2007) and used by coaches, however, we would exclude these as 'agility' tests because they did not require a reaction to a stimulus.
This lack of consensus with respect to a definition of agility is stark when compared to other physical attributes like aerobic conditioning. Aerobic conditioning is based on either the direct measurement or an indirect estimation of maximal oxygen uptake. The measurement of physiological gas exchange is the "gold standard" laboratory test that has given rise to validated sub-maximal or field-based tests. The protocols are well established and highly researched. In the case of agility, many of the authors fail to report the procedures by which they arrived at a new test protocol, making replication difficult.
The lack of methodological clarity is less frequent in the literature published since 2008. In 2002, Young and colleagues first identified the limitations of Chelladurai's (1976) model. The 2002 model proposed an alternative that focused solely on "universal" agility, and identified two major contributing factors to successful agility performance: CODS and perceptual/decision-making factors. Sheppard and Young (2006) described the uniqueness of Chelladurai's 1976 model, and its usefulness for coaches and sport scientists to better classify skills specific to a particular sport. Such knowledge allows for the creation of tests / drills that target the sub-components of a skill or the overall skill itself. For example, the design of agility tests can be improved, but what impact does muscular strength or anthropometrics have on agility and its performance? These and other elements compose the model proposed by Sheppard and Young (2006). Spiteri et al. (2014) investigated some of these elements by measuring muscle cross-sectional area, strength, and electromyography in professional female basketball players and found that eccentric strength was correlated with CODS tests, but not with tests of agility. Combined, the work of Chelladurai (1976); Sheppard and Young (2006) and Young et al. (2002) has advanced 'agility' as a concept that can be investigated for the purpose of talent identification as well as monitoring progress following a training program.
The 3-Cone Test is an example of a CODS test that has been used, incorrectly in the authors' opinion, to quantify 'agility'. To provide a consistent terminology for the 3-Cone Test, as well as the modified versions examined in the present study we propose 3CT as an acronym. In fact, the 3CT reported in the literature dictates that the runner makes a change of direction to the right (further detail in the methods section). In an attempt to make that clear to practitioners, we identify this as 3-Cone Test-Right (3CTR).
In view of the high-profile use of the 3CTR by strength and conditioning professionals, and lack of published data on the test, an investigation into the test's reliability is warranted. In addition to replicating the reliability of the 3CTR test, (Stewart et al., 2014) the goal of the present study was to re-design the test so that it met the definition of 'agility' provided by Sheppard et al. (2006), namely "a rapid whole-body movement with changing velocity or direction in response to a stimulus", and examine the test re-test reliability of three versions of the 3-Cone Test (3CTR).
In order to keep the terminology consistent, the version in which the runners are required to change direction to the left is 3-Cone Test-Left (3CTL) (additional details found in the methods). The two additional modifications to the 3CT require a reaction to a stimulus and are denoted as 3-Cone Test-Agility-Right (3CTAR), and 3-Cone Test-Agility-Left (3CTAL) respectively. Each of these tests is described in detail in the methods section, generally the test design is the same as the CODS versions except the runner will be cued to go either right or left based on the stimulus provided by the tester.
The hypotheses were (a) the 3CTR will be reliable (intraclass correlation coefficient (ICC)>0.75) when testing untrained college-aged men; (b) the three modifications 3CTL, and 3CTAR, and 3CTAL versions of the 3CTR will be reliable (ICC>0.75); and (c) correlation coefficients amongst the four tests will be moderate (r>0.75) to high (r>0.85).
Data was collected on 49 men (age, 20.97 [+ or -] 1.67 years; height, 1.81 [+ or -] 0.06 m; body mass 85.1 [+ or -] 18.3 kg), however, nine failed to complete at least one of the required trials, leaving the final sample size at 40. Convenience sampling was used to recruit participants from the student body at a mid-Atlantic university in the...