Original article written by Gianmarco Ciocca, Antonio Tessitore and Harald Tschan.
Background
Agility and change of direction (COD) ability are considered to be independent skills based on a relatively low statistical commonality [1]. This means that an athlete may be good at COD ability but not necessarily be good at agility. The research that has found this is based on single tests of the two tasks. However in many team sports, repeated efforts are required that causes fatigue, and it is not known whether the relationship between COD ability and agility holds up under fatigue. Therefore, the purpose of this study was to compare the fatiguing pattern of repeated COD and agility tasks, and to see if the two tasks could be regarded as different and independent skills.
What the authors did
Fourteen National level youth soccer players (gender not stated) were assessed on a repeated COD (RCOD) test and a repeated agility (RA) test on different days, separated by six days in a counterbalanced order. The tests involved the same Y-shaped movement pattern (Figure 1), with the only difference being that the COD direction task was pre-planned but the RA test required the athletes to react to a flashing arrow to suddenly turn to the left of right. In both tasks, the athletes performed 20 repetitions with a 10s recovery, producing a work:rest ratio of about 1:5. The 20 reps were broken down into 4 blocks of 5 reps to analyse the progression of fatigue from one block to the next.
What the authors found
There was a statistically significant (P<0.05) slowing of performance across the 20 repetitions, indicating that fatigue was present. The % decrement of the total time was similar for both tasks at around 7.5%. The time taken to complete the task was slower for the agility condition in all four blocks (P<0.05), indicating that the two conditions were different. The correlations between the two tasks were relatively low (r=0.17 to r=0.54) for each block of five reps, indicating that repeated COD and repeated agility could be considered as independent skills. The authors suggested that the difference between the two conditions was due to the presence of the reaction (decision-making) in the agility test.
Limitations
As acknowledged by the authors, a limitation of this study is that the agility test lacks ecological validity. This means that it does not represent the agility demands of match play in soccer very well because of the non-specific stimulus used. The researchers chose to use a flashing arrow to direct the turn to the left or right rather than a human stimulus because of its ease of use, its use in previous research, and its reliability. Another limitation of the study was that the reaction time in the agility test was not isolated. Therefore, the question of whether fatigue specifically impairs reaction time and decision-making ability differently to movement time could not be investigated.
What this means for coaches
The authors did not offer any practical applications, however the main message from this study is that it reinforces the notion that COD ability and agility are different skills, whether performed in an unfatigued state or under significant fatigue. Even when both tasks followed the same Y-shaped pattern, the inclusion of having to react to an unpredictable stimulus changed the nature of the task. Therefore, practitioners should not assume that performance in a repeated COD test such as the one used in this study automatically represents what will happen in a repeated agility task.
Reviewer’s comments
From my research and personal observations, footwork changes when an athlete is required to react to an unexpected stimulus, regardless of whether the stimulus is generic like a flashing arrow, or a person performing a sidestep. When performing a pre-planned COD, you will probably execute a sidestep technique so that your outside leg pushes laterally into the ground to propel your whole body in the opposite direction. However, when you don’t know which way the stimulus will be directed, you have to be prepared to turn to either the left or right. This usually means that you will perform a different technique such as a split step (landing on both feet at the same time), or some small shuffle type steps in readiness for the decision. This suggests that agility can be different to COD skills due to technical, as well as cognitive factors, and reinforces that you should not assume that COD training will automatically transfer to agility performance.
Recommended resources
Article – Agility and change-of-direction speed are independent skills: implications for training for agility in invasion sports – Warren Young and colleagues
Article – Pillars of effective movement strategy and technical execution for change of velocity – Paul Gamble