Fourth quarter fade-out - is it an excuse?
Issue: Volume 27 Number 3
As a match draws into its final stages an athlete’s skill level is often seen to deteriorate, with coaches and commentators alike tending to blame this decline on increasing levels of fatigue. Skill Acquisition and Physiology scientists at the Australian Institute of Sport (AIS) have recently attempted to determine this perceived relationship between skill and fatigue.
In an open-skill team sport such as water polo, proficient performance is the combination of smart decision-making and quality skill execution. Although the relationship between these performance components is well understood, the impact fatigue has on both the decision-making and skill execution ability of athletes is not. Specifically, it remains unclear how decision-making and skill execution are affected by fatigue late in a game and if there are any similarities between how these two components are impacted. Research was conducted at the AIS to determine how increasing levels of fatigue effected decision-making accuracy and goal shooting accuracy, velocity and proficiency in highly trained water polo players.
Research in Action
Initially, a sport-specific, fatiguing test was developed that incorporated water polo specific movements. Fourteen junior elite male water polo players, all scholarship holders at the AIS, participated in the study with testing focusing on decision-making and technical shooting performance. Players completed the tests on alternate weeks to assess each of these components separately. For each of the two sessions, athletes completed four sets of an eight-repetition fatigue drill with each repetition lasting approximately 18-seconds and completed at maximal intensity. The proposed exertion levels and rest duration allocated during each set are detailed in Table 1.
Table 1: Proposed exertion levels and rest duration allocated for each set
|
Set 1 |
Set 2 |
Set 3 |
Set 4 | |
|---|---|---|---|---|
| Exertion level | Light | Moderate | High | Very high |
| Rest duration | 80 seconds | 40 seconds | 20 seconds | 10 seconds |
The decision-making test consisted of five video-based tests. The first was conducted prior to the fatigue intervention and the remaining four followed each of the four fatiguing sets. In each test, 12 clips of elite level games were displayed on a 1.4m plasma screen located on pool deck. At a critical point in play, where an offensive decision had to be made, the screen was blackened. Athletes, baulking a ball in the pool, were required to call out their answers to a scribe within one second of the footage disappearing. For the technical shooting test occasion, five tests were again conducted with athletes aiming 12 consecutive shots at the corners of a water polo training target working in a clockwise direction. Shot accuracy and velocity were measured for each attempt, and technical performance of the shots was later analysed using a biomechanical checklist.
To determine that the athletes were becoming fatigued, heart rate was recorded following each repetition. Rate of Perceived Exertion (RPE) was recorded after each set and blood lactate concentration was taken immediately after the athlete completed each of the decision-making or shooting tests. Heart rate and RPE were also taken following each test.
Findings
Contrary to expectation, the results showed that decision-making performance actually improved when the athletes were under conditions of very high exertion. Shooting accuracy and velocity were largely unaffected, while shooting technique declined under very high levels of exertion. Success of the fatigue drill, in generating increased exertion and subsequent fatigue was confirmed via the significant increases found in heart rate, RPE and blood lactate concentration at very high levels of exertion, compared with the sets and tests conducted at rest and the lighter exertion levels.
The findings of the study suggest that working at such high levels of exertion may have actually benefited the attentional resource allocation utilised by the elite participants. Resource allocation is closely linked with the theory of attentional narrowing. This theory suggests that as arousal increases, fewer stimuli are detected within the visual field and a greater amount of resources are allocated to the tasks that are most relevant. For example, when playing conditions become highly stressful, tasks requiring more attention are allocated a greater portion of the resources available. However, depending on the skill level of the performer, the allocation of resources can be compromised and can negatively impact on performance. Novice players begin to miss relevant cues important to the successful completion of the task at hand. In contrast, expert athletes efficiently allocate attentional resources to the most important performance aspects, resulting in a form of positive attentional narrowing. In the current study the athletes were highly skilled and familiar with functioning under extreme exercise conditions and hence they may have experienced this positive narrowing despite high levels of physiological arousal.
Applications
In responding to the commonly asked question of fatigue causing decrements in performance, results from this study suggest that junior elite athletes are able to tolerate very high levels of physiological stress. As a consequence fatigue was found to have a differential impact on decision-making and skill execution processes. These findings support the concept of having athletes perform decision-making and technical skill drills under higher levels of exertion, and subsequent fatigue, than is usually the case.
One important qualification to consider is the enhanced risk of injury. Results of this study indicated that the technical performance of skill did get worse under conditions of high fatigue, even though shooting accuracy and velocity were maintained. The components of skill that were found to deteriorate were identified as those more closely related to prevention of overuse injuries, rather than affecting the technical delivery of the skill. When implementing technical skill drills and decision-making training under conditions of high exertion or fatigue it is important to monitor technical performance and ensure technique does not deteriorate to the degree where injury to the athletes is more likely to occur.
On a more positive note, training under conditions of elevated fatigue is not only competition specific, but previous evidence suggests athletes still engage in learning. By training athletes when fatigued, short-term performance may initially deteriorate, but permanent improvements may occur over time, and importantly transfer to enhanced match performance. It is also likely that when higher intensity training is combined with elevated levels of game-specific arousal an even stronger transfer of performance effect may well occur. Maybe fatigue really is just offered as an excuse a little too often!
Further Reading
Royal, K.A., Farrow, D., Mujika, I., Halson, S.L., and Pyne, D. (2003) The effects of fatigue on decision-making and shooting skill performance in water polo players. Report submitted to the Australian Sports Commission.
Acknowledgements
The extensive contributions of Dr Damian Farrow, Dr Iņigo Mujika, Dr Shona Halson and Dr David Pyne, is gratefully acknowledged. Much appreciation is also extended to the athletes and coaches of the Australian Institute of Sport Water Polo program. The study was funded by the Australian Sports Commission.
