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Calibrating and recalibrating action capabilities

"Action capabilities change across longer time scales as a result of development, ageing and training. When body dimensions and action capabilities change, for example through development or ageing, actions that were once possible may become less possible or vice versa (see Fajen et al., 2009)." - Araujo and Davids, 2011

All-Ireland hurling final 2022. Full house. Limerick 1-31 - 2-26 Kilkenny.

Hurling. Camogie. Baseball. Cricket. Tennis. Badminton. Hockey. Golf. There are many more. Sports that require an athlete to control an implement in order to control and strike the ball. I have attempted a number of them on a number of occasions (see video below), with varying success, which is a sign of a novice performer - variability of process with variability of outcome. But these sports can provide a really insightful metaphor as to why an athlete needs to consistently engage in relevant tasks that link perception (information) and action (movement). If we take hurling, and as an example, a hurler spends 5 years playing with the same 32-inch hurl. He has calibrated his striking, his control, his hooking, his blocking, his skills to this hurl. At the start of a new playing season, he transitions to a 34-inch hurl. But the transition isn't smooth initially. For the first two weeks of the season, he was struggling to strike off the sweet spot and missing his first touch. But after the initial two weeks, it's like he has been playing with the hurl for years. This is the recalibration process. In layman terms, he has to get used to his new stick. And depending on the initial skill level of the hurler in question, this recalibration could take minutes, it could take days, it could take weeks.

I may or may not have lost this ball.

A play on Heraclitus' renowned quote sums up this post perfectly:

"No athlete ever faces the same problem twice, for it is not the same problem and they are not the same athlete."

The problems that athletes face are always evolving and changing (something I have touched on here), as are the action capabilities that an athlete possesses. While a changing environment creates the need for an athlete to be attuned to specifying information, ever-evolving action capabilities alters the affordance landscape of an athlete.

I have written a lot about skill adaptability, coadaptability and skilled intentionality. These processes all stem from the relationship between an athlete and their environment. Skill development is not a tick box exercise - one and done. As in, once a player catches the ball overhead in Gaelic football or American football; once a player makes a successful tackle in soccer or rugby; once they complete a given task - they do not have their learning of that skill complete. Skilled performance is a constant cycle of adaptability - and every display of skill takes on a life of it's own. An athlete's development is never complete. With all the variability that is present in their environment (and their own body as we will discuss), how can they adapt the goal-orientated behaviour to still achieve a task? This post is more about the variability that occurs within an athlete's body, which generally occurs over a longer timeframe.

  • What happens to a player who is going through puberty and through a rapid growth spurt - peak height velocity (PHV) and peak weight velocity (PWV)?

  • What happens when an adult player engages in a progressive strength training program over the course of 6 months?

  • What happens if a player suffers a serious long-term injury? Or a recurrent injury?

Each of these scenarios present unique problems. Some can lead to positive changes in performance, and the challenge for a coach is to harness that potential in a player. It may be filling the player with confidence to go and express their potential, or it may involve resetting a player's intentions or cognitions (see Vincent Kompany video below). Some can lead to negative changes, and the role of a coach is to create an environment so the player can regain their confidence. Any high-performing athlete who regains or exceeds their performance levels after a severe injury should not be taken for granted. It doesn't always happen. Arguably (and admittedly I am not an expert), Virgil Van Dijk for Liverpool hasn't regained his form since the severe injury he suffered (there may be other reasons for this aside from his injury). It takes high levels of diligence and dedication by the athlete themselves and their support structure. For an insight into the recovery path following a severe injury, see here. In any case (maturation, athletic development, injury rehabilitation), every athlete needs to be given opportunity to continuously calibrate, and recalibrate their actions to the constraints acting on them at any given moment, and this includes the individual constraints. See below for Newell's model of constraints, and where individual constraints fit into the overall picture (or, read here).

Growth, Maturation and Development

As many of the coaches I am currently working with are working with boys aged 6-18, both in a school and a rugby club setting, this has been something that I have been educating coaches on in recent times. Understanding and empathy for what youth players are going through is critical to ensure that coaches provide players with a positive meaningful sporting experience to set them up for a lifelong engagement in sport and physical activity (for more on this, read about defining the role of a physical education teacher, or an ecological approach to physical education). A snippet from a recent message I shared with coaches:

it is almost impossible for a kid to go through their whole underage playing career without a period of underperforming (not playing as well as expected), because they essentially have to get used* to having a different body (changes due to growth, maturation and development). It is vital that we, as coaches, are empathetic with this, we SUPPORT players through challenging periods, and we manage expectations (coaches, players, teammates and parents).

*Get used to = recalibrate as above.

Growth can be defined as an increase in size of the body or specific parts of the body (Lloyd and Oliver, 2020). Maturation is the process of becoming mature. Development is the complex interaction between an individual's growth and maturation and how they develop physically, emotionally, socially and cognitively. There are a number of changes that occur in a young person's body, and while I am currently only working with boys' programs in my current roles, it is important to be aware of the changes that occur in girls too:

  • In boys, fat-free mass increases while fat mass decreases. Pre-puberty changes in body composition follow a similar pattern in boys and girls, however, post puberty, boys' fat free mass is 25-30% greater than girls and their fat mass is about half that of girls. This is due to the increase in circulating androgens in boys compared to girls.

  • Max strength in boys increases in a curvilinear fashion from childhood to maturity. For girls, increases plateau during mid to late adolescence.

  • Power output increases from childhood to adulthood in boys and girls.

  • Aerobic power increases from the ages of 8-12 in boys and girls. The increase continues in boys into adulthood, while girls' increase falls behind.

  • Changes in physical fitness through childhood and adolescence are largely due to changes in body size and composition (see point 1).

  • PHV can vary from the ages of 11-16 in boys (with peak growth rates of 6-13cm per year), and 10-15 in girls (with peak growth rates 5-11cm per year). The growth spurt in boys is longer and more intense than in girls.

  • Soon after PHV (a few months to a year), PWV occurs. This is measured in rates of kg per year. However, PHV is genetically pre-determined, and PWV is influenced more heavily by environmental factors.

In summary, the changes that a young athlete experiences are huge. For coaches working with young athletes, it is important to be aware of these changes. With this level of development in physical qualities, it is clear that a player's potential after puberty will increase, provided they are given an opportunity to appropriately recalibrate to their new action capabilities. With new action capabilities, an athlete's affordance landscape will be altered. The process of changing action capabilities is not limited to growth and maturation but can also be impacted positively by a specific training program, or negatively by a severe injury.

The benefits of athletic development

When an individual engages in a strength and conditioning (S&C) program, it generally contains a combination of lifts, jumps, throws and sprints. Simply, the aim of a S&C program is to make an athlete stronger, or fitter, or faster, or all three. The purpose of this post is not to dive into writing an S&C program. For my own guiding framework that I have used for S&C programs in the past, see here.

Lets take a player in Gaelic football, any position. A big part of the game is fielding the ball (although maybe not as big as it has been in the past, and dependent on a teams tactical approach). Any player anywhere on the field may have to execute a high catch. See video below for some great examples. From an athletic development standpoint:

  • How would having greater power impact a players' high catching ability?

  • How would a player having a great range of motion around their shoulder impact on their ability to reach above their head?

  • How would a player being stronger and heavier impact their ability to jostle another player in their run-up?

High catches in Gaelic football. Full video here.

Being better conditioned to play the game and compete would never be a bad thing. But it is never as simple as "a player just needs to get stronger" or "a player just needs to lose some bodyfat". These things will help, but they are only part of the process. The challenge for coaches is to ensure that players are getting enough opportunity to recalibrate their newly acquired action capabilities. Sometimes it will be about confidence and trust in their own action capabilities. They can take an extra step in their run up because they can jump and extra 5cm. They can compete to catch above their opponent instead of just trying to break the ball. The examples given has been around jumping and fielding, but this concept applies to all skills required in all sports. Athletic development supports on field performance, provided coaches keep the main thing the main thing.

The impact of severe injury

An attacker in Australian rules football is running through on goal with one defender to beat. They shape up like they are going to shoot off their right foot, the defender commits to that side and a gap opens up to evade. The attacker plants their right foot outside of their centre of mass to step inside (attempted display of Skilled Intentionality), their knee buckles and they rupture their right anterior cruciate ligament (ACL).

I have made the story up, but ACL injuries are quite prevalent in sport, and they have become somewhat of an epidemic in recent times, particularly in women's soccer (football) (read here). The mechanism of injury may vary a bit, but again, explaining ACL injury is not the aim of this post. The point is more around the long-term impact of the injury. A player could rehab and complete their return to play protocol diligently, check all the boxes and exceed their strength and performance levels from pre-injury. But their match performance may still be well below that of pre-injury. This highlights a crucial aspect of skilled performance: one of it's biggest influences is the athlete's mindset and confidence, and their subsequent intentions. In the context of Newell's model of constraints (see below), this all forms part of the individual constraints.

Take the example above, the attacking player is predominantly left-footed. Over a long period of time, they planted their right foot thousands of times to push off and create space for a left-footed shot or pass. However, now they have some doubt about their ability to push off. When they do push off, it is not as powerful as it once was. This isn't due to regressed strength and power levels, but rather reduced confidence and belief in their own body to do what it once did. They are afraid to "attack the ground" powerfully to enable them to accelerate away from their opponent. Now, they might look for opportunities to offload rather than create a scoring opportunity. While their physical capacities have improved from pre-injury (albeit in reductionist measures), the action capabilities have changed and thus, their affordance landscape has too.

This is an example of how an athlete's journey can negatively impact their performance. Another example can come in the form of a recurrent hamstring injury, the mechanism of which is max sprinting. If this happens often enough (often enough is different for each individual), then the athlete will, consciously or sub-consciously, reduce their max sprinting speed to protect their hamstring and reduce injury. As with the ACL injury, their action capabilities have changed, which will influenced their affordance landscape.

How can a coach help an athlete overcome this? In a similar way to before, this might be about trust and confidence in their newly acquired action capabilities since their injury. Providing evidence to the player about their physical conditioning, and how it compares to their pre-injury levels, and giving players opportunity to express their action capabilities in simplified and progressively more complex tasks are possible ways to assist the process. But it may take time, and in the same way young athletes need support when going through puberty, all athletes need support when going through long term rehab. The video below is a great account of 1) how a severe injury can impact an athlete, and 2) the positive impact a coach can have on an athlete returning from a severe injury.

Vincent Kompany talking about how a severe injury impacted him and how his coach helped him through it. Full video here.


The information in this post can be summarised by asking the question - "what imapct does an individual have within the perception-action loop?" (see image below.) Obviously, the impact is massive. But the it is so important that a coach is aware of how the individual is developing. And whether this development is positive or negative. This has massive implications for coaches in both development environments (age-grade teams) and performance environments (as highlighted above). Any athlete is not the same as they were 5 days ago, and certainly not the same as they were 5 years ago.

Karl Newell's model of interacting contraints (Davids et al., 2003).


- Araujo, D., & Davids, K. (2011). What Exactly is Acquired During Skill Acquisition? Journal of Consciousness Studies, 18, 7-23.

- Davids, K., Araujo, D., Shuttleworth, R., & Button, C. (2003). Acquiring skill in sport: A constraints-led perspective. International Journal of Computer Science in Sport, 2, 31-39.

- Fajen, B. R., Riley, M. A., & Turvey, M. T. (2009). Information, affordances, and the control of action in sport. International Journal of Sport Psychology, 40, 79-107.

- Lloyd, R., & Oliver, J. (2020). Strength and Conditioning for Young Athletes (2nd Edition ed.).


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