Part 2: System 1, System 2, and the Behavioural Architecture of Athlete Preparation

Applied Behavioural Sports Science Series

Part II: Why Athletes Don’t Do What They Know

In contemporary high-performance sport, improvements in strength, aerobic fitness, body composition, power, etc., are commonly explained through the lens of structured and periodised training. In this sense, load is prescribed and adaptation is expected, and typically performance change is attributed to physiological mechanisms. However, beneath these explanations sits athlete behaviour which is the true fundamental driver of adaptation. Consequently, athletes do not adapt to training intentions, programmes, or planning documents; they adapt to the behaviours they repeatedly enact within their preparation environment. Therefore, any serious attempt to influence performance must begin with the psychological architecture that governs behaviour not with physiology..

Kahneman’s dual-process model (System 1 & System 2 Thinking) offers a particularly useful starting point for this discussion. This model provides a robust, empirically grounded explanation for why athletes often behave in ways that contradict their stated goals, coaching instructions, or even their long-term professional interests. When interpreted through a systems-thinking lens, the model reveals why certain preparation behaviours become stable and self-sustaining, while others remain fragile despite repeated intervention. The issue is typically a misalignment between how behaviour is designed and how cognition actually operates in real-world settings, and not a lack of knowledge or motivation..

This chapter examines the implications of dual-process cognition for athlete preparation, with specific reference to behaviours surrounding nutrition, strength training, recovery, and conditioning. It argues that effective behavioural change in sport requires acknowledging the dominance of automatic cognitive processes (System 1) and designing preparation environments accordingly. This position aligns closely with behavioural design frameworks that conceptualise behaviour as an emergent outcome of ability, triggers, constraints, and competing demands and not as a simple product of motivation . Within high-performance systems, behaviour is rarely chosen in isolation; it is shaped continuously by context.

Dual-Process Cognition in High-Performance Sport

Dual-process theory distinguishes between two interacting cognitive systems. System 1 is fast, automatic, habitual, and emotionally driven. System 2 is slow, deliberate, effortful, and analytically driven. While both systems contribute to athlete decision-making, System 1 governs the majority of daily behaviour, particularly routine actions, low-salience decisions, and behaviours that require sustained consistency rather than conscious effort.

This imbalance is amplified in high-performance environments, where athletes operate under persistent physical load, cognitive demand, emotional stress, and time pressure. Under these conditions, the capacity for System-2 regulation is diminished. and fatigue, stress, and attentional depletion reduce the likelihood that athletes will engage in deliberate planning or rational self-control. Consequently, System 1 increasingly governs preparation behaviours, often outside conscious awareness.

For practitioners, the implication is that most behaviours athletes struggle to maintain such as sleep consistency, nutritional adherence, recovery routines, and training intent, are governed primarily by System 1, not System 2. This observation directly challenges prevailing coaching assumptions, which often treat behavioural failure as a knowledge or motivation problem. In practice, many interventions rely heavily on System-2 mechanisms such as education sessions, goal-setting, rational persuasion, performance reviews, despite targeting behaviours that are executed almost entirely through automatic processes.

The Preparation Gap: When Cognition and Design Misalign

This mismatch is evident in everyday interactions across high-performance sport where athletes are routinely told they need to improve body composition, be more consistent with recovery, lift with greater intent, or meet conditioning targets more reliably. These messages appeal to System 2. They assume that once an athlete understands the rationale then the behaviour will invariably follow.

However, the behaviours that drive improvements in body composition, strength, recovery, or aerobic capacity are embedded in System-1 processes. For example, meal timing is habitual and food choices are influenced by availability and visibility. Post-training eating is shaped by emotional state and fatigue and training intent fluctuates with mood, arousal, and social context. Bedtime routines follow defaults rather than plans and recovery behaviours compete with convenience, social norms, and energy conservation.

These behaviours emerge automatically in response to environmental cues and are not reliably governed by reasoning, intention, or long-term planning. As Kahneman has observed, System 2 is effortful and inherently reluctant; it is invoked selectively and sparingly. So, when behaviour depends on sustained System-2 engagement, it is vulnerable to collapse under load.

This explains a familiar pattern in elite sport: athletes agree with performance recommendations, articulate them accurately, and yet fail to enact them consistently. Therefore, the issue is is cognitive architecture and not compliance.

Behavioural Design as a Diagnostic Tool

Behavioural design frameworks provide a practical method for diagnosing why behaviours fail to occur. Rather than defaulting to assumptions about discipline or motivation, these frameworks propose that behaviour depends on a small set of interacting conditions such as motivation, ability, timely triggers, environmental and social constraints, and the presence of competing behaviours.

This approach is particularly valuable in high-performance sport because it reframes behavioural inconsistency as a systems issue rather than an individual flaw. For example, an athlete who repeatedly skips post-training recovery may not lack motivation. The recovery space may be inconveniently located, which may increase friction. There may also be no cue prompting the behaviour once training ends. Alternatively, senior players may not model the behaviour, which may weaken social reinforcement. Additionally, fatigue may bias the athlete toward energy-conserving choices and the behaviour may require additional decision-making at a point of cognitive depletion.

Viewed through this lens, behavioural inconsistency is the predictable outcome of a system that makes certain behaviours easier than others and, therefore, is rarely irrational. When analysed properly, most preparation failures reveal a design problem rather than a character deficit.

System 1 in Practice: Preparation Behaviours Revisited

The dominance of System 1 becomes especially clear when preparation behaviours are examined in detail.

Body composition changes emerge from repeated nutritional actions which are driven by habit, convenience, emotional state, and environmental exposure. Education and planning can support change; however, behaviour shifts only when food environments, defaults, and routines are altered.

Strength development depends not only on programme design but on intra-session behaviours such intent under the bar, adherence to progression, completion of accessory work, and consistency across weeks. These behaviours are shaped by atmosphere, training partners/teammates, music, and emotional arousal, which are factors that operate largely through automatic processing.

Aerobic development is similarly constrained. Athletes may understand conditioning targets, yet pacing and effort distribution are guided by affective responses, perceived exertion, and social comparison. Without structured constraints or feedback loops, System-1 heuristics dominate execution.

Recovery behaviours are perhaps the most vulnerable. Unless routines are frictionless, habitual, and socially reinforced, athletes default toward energy-saving options such as leaving early, skipping modalities, or deferring actions.

Across all domains, the physiological adaptation is driven by behaviour, and the behaviour is governed predominantly by System 1.

Designing for the Dominant System

If preparation behaviours are System-1 driven, then effective intervention requires designing environments that align with automatic cognition. This approach is consistent with both behavioural design and complex systems theory, which emphasise shaping conditions rather than prescribing actions.

System-1-aligned interventions reduce friction, introduce cues, leverage social norms, structure defaults, minimise cognitive load, and modify physical constraints. Examples include placing recovery stations along exit paths, making protein intake the default post-training option, pairing athletes strategically, and designing spaces that guide flow rather than demanding choice.

System-2 strategies such as education, planning, reflection, and goal-setting, remain valuable; however, they are supportive rather than primary. They explain why a behaviour matters but does not ensure it occurs. In this sense, when behaviour depends on System 2, it remains fragile, whereas when it is designed for System 1, it likely becomes stable.

Dual-Process Cognition Within Complex Systems

Complex systems theory holds that behaviour emerges from the interaction of individual, task, and environmental constraints and dual-process theory explains how those constraints are translated into action through automatic cognitive processes. Together, they offer a powerful synthesis indicating that System 1 functions as the behavioural engine of the athlete and System 2 provides direction but not propulsion. and, finally, the environment acts as the architect of System-1 behaviour.

From this perspective, sustainable behavioural change is achieved through constraint design and small changes to environment, defaults, or feedback loops that can change behaviour patterns over time.

Conclusion

Athlete preparation behaviours are not governed by rational analysis but by automatic processes shaped by context. Dual-process theory explains why athletes often fail to enact desired behaviours despite high motivation and clear intention and behavioural design frameworks reveal how those behaviours can be stabilised through environmental change.

For practitioners, the implication is that performance improvement depends on designing systems in which the right behaviours occur by default and less on convincing athletes what to do. In complex adaptive systems, it is these small, well designed amendments in constraint architecture that generate durable behavioural patterns and sustained performance change.