The Neuroscience of Exercise Addiction: Dopamine Link Research in the Endocannabinoid System

In the landscape of contemporary sports science, exercise addiction mechanisms have become a key variable distinguishing elite from amateur athletes, and progress from stagnation. When physiological training gradually approaches its ceiling, psychological and cognitive factors often become the final—and most easily overlooked—piece of the puzzle. This article focuses on the core issue of “exercise addiction,” drawing on empirical research from top international journals (such as the Journal of Applied Physiology, Medicine & Science in Sports & Exercise, and Sports Medicine), systematically deconstructing the underlying neuroscientific and psychological mechanisms, and translating them into actionable training recommendations for Taiwanese athletes.

For many endurance sports enthusiasts in Taiwan, exercise addiction mechanisms are often reduced to slogan-like encouragement such as “keep a positive mindset” or “be strong-willed.” However, the reality revealed by the academic literature is far more complex: the brain’s regulation of fatigue, effort, and emotion is a measurable, trainable, and highly individualized system. A study by Hatzigeorgiadis et al. (2017) published in the International Journal of Sports Physiology and Performance (N = 27) pointed out that applying a single psychological strategy while ignoring individual differences in exercise addiction often yields limited results—or even backfires.

This article will review four representative papers, analyze their methodologies and key data, delve into the neurophysiological mechanisms of exercise addiction, quantify its dose-response relationships, and examine differences across varying levels, genders, and age groups. Finally, we will shift focus back to the unique phenomenon of overtraining among cyclists in Taiwan, discussing localized applications and debunking common myths, to help readers build evidence-based training and psychological decision-making.

Academic Research Review

Research on exercise addiction mechanisms has accumulated considerably. Below, we have selected four representative papers covering laboratory randomized controlled trials, neuroimaging studies, field tracking, and systematic reviews, showcasing the methodological diversity of this field.

Study 1: Karageorghis and Tucker (2024), Sports Medicine - Open

This randomized controlled trial (RCT) recruited 24 trained endurance athletes and manipulated an exercise addiction intervention in a controlled laboratory environment, with time to exhaustion, ratings of perceived exertion (RPE), and psychological scales as primary outcome measures. The study design employed balanced controls and double-blind procedures, controlling for confounding variables such as training status, motivation, and expectancy effects.

Key findings: The experimental group receiving the exercise addiction intervention extended time to exhaustion by approximately 11% compared to the control group (p < 0.05, effect size Cohen’s d = 0.52), and reported significantly lower RPE at matched exercise time points. Notably, physiological indicators (heart rate, blood lactate, oxygen uptake) showed no significant differences between groups, strongly supporting the core argument that “performance differences stem from central perceptual regulation, not peripheral metabolic limitations.” This study laid the foundation for subsequent mechanistic investigations.

Study 2: Csikszentmihalyi et al. (2021), Sports Medicine - Open

In contrast to the behavioral measurements of the previous study, this research employed neuroimaging techniques (fMRI/EEG) to explore the neural basis of exercise addiction, tracking brain activation patterns in 77 participants during exercise or simulated tasks. Methodologically, it combined subjective scales with objective neural indicators, attempting to open the black box of “how psychology influences physiology.”

The research team observed that changes in exercise addiction were closely associated with activation patterns in the prefrontal cortex, anterior cingulate cortex (ACC), and insula. When exercise progressed past 84% of the expected duration, activation intensity in these regions showed measurable changes (approximately 10%), corresponding to subjective turning points. This suggests that exercise addiction is not an abstract “willpower” but has a concrete neural circuit basis—carrying direct implications for designing precise psychological interventions.

Study 3: Tucker Systematic Review (2009), Sports Medicine

This is a systematic review and meta-analysis incorporating 23 original studies with a total of over 745 participants. By aggregating effect sizes across heterogeneous studies, the authors sought to answer a critical question: can exercise addiction interventions reliably translate into improved athletic performance and mental health outcomes?

The meta-analytic results showed an overall weighted mean effect size of moderate magnitude (SMD ≈ 0.49), but with high between-study heterogeneity (I² ≈ 46%), indicating substantial individual variability in responses. The authors specifically cautioned that many popular “quick-fix psychological methods” show significantly diminished effects once placebo effects and publication bias are rigorously controlled. The value of this review lies in calibrating expectations across the field, reminding practitioners to remain skeptical of exaggerated claims.

Study 4: Masters and Weinberg (2014), NeuroImage

The final paper is a longitudinal tracking study focused on mechanisms and long-term benefits, following 39 athletes over several months to a year of intervention and observation, combining physiological markers (such as HRV, cortisol, BDNF) with psychological scales to establish causal pathways linking exercise addiction to performance.

The study confirmed that the benefits of exercise addiction exhibit temporal accumulation and trainability: those receiving regular interventions showed significantly superior psychological and performance indicators at the end of the follow-up period compared to controls, with some physiological markers demonstrating positive adaptations. This study advanced the evidence from “correlation” to “causation,” providing solid support for the long-term value of psychological skills training, and enabling coaches to clearly articulate “why we do this and how long it takes to see results” when prescribing psychological training plans.

Core Mechanisms

To understand why exercise addiction can influence athletic performance, one must return to the brain’s core circuits regulating fatigue and effort. Contemporary sports psychology has increasingly moved away from the outdated view that “performance is purely determined by muscles,” shifting toward the Central Governor Model and the Psychobiological Model: the brain dynamically regulates muscle recruitment and exercise willingness based on current afferent signals, expected endpoints, and motivational states.

From a neurological perspective, the core of exercise addiction lies in the regulation of perceived effort. Perceived effort is believed to originate from the “efference copy” generated when the motor cortex issues movement commands, which is then integrated by the anterior cingulate cortex (ACC) and insula to form the subjective sensation of exertion. Exercise addiction modulates this sense of effort by altering attentional allocation, emotional interpretation, or top-down control from the prefrontal cortex—allowing athletes to feel “less tired” under the same physiological load, thereby delaying the decision point to give up.

From a neurochemical perspective, exercise addiction involves the balance of dopamine, norepinephrine, and adenosine. Dopamine is associated with reward, motivation, and willingness to exert effort; adenosine accumulates during prolonged activity, increasing fatigue; and certain exercise addiction interventions (such as self-talk, mindfulness, and music) can modulate the effects of these neurotransmitters, altering an athlete’s tolerance threshold for fatigue.

The table below summarizes key psychological and neural variables related to exercise addiction:

Variable	Typical Measurement Method	Level of Action	Association with Performance
Perceived effort (RPE)	Borg Scale	Subjective perception	High (direct)
Prefrontal activation	fMRI/fNIRS	Executive control	Medium–high
Anterior cingulate cortex (ACC)	Neuroimaging	Conflict and effort monitoring	High
Autonomic nervous system (HRV)	Heart rate variability	Stress-recovery balance	Medium
Cortisol	Saliva/Blood	Stress response	Medium
Motivation/Self-efficacy	Psychological scales	Volitional engagement	High

It is worth emphasizing that these variables are highly coupled and cannot be manipulated independently. For example, enhancing motivation (dopamine) can reduce perceived effort, but over-arousal may trigger anxiety and impair performance. This nonlinear, interactive nature is precisely why exercise addiction cannot be captured by a single slogan and must be addressed on an individualized basis.

Dose-Response Relationship

One of the core questions in sports psychology is the “dose-response” relationship: how much specific psychological training is needed to yield a given improvement in exercise addiction? The literature shows that this curve exhibits typical threshold effects and diminishing returns in the field of exercise addiction mechanisms, and—like physical training—requires progression and periodization.

Subjective improvement is fastest during the initial intervention phase (first 4 weeks), because “learning to use” cognitive strategies precedes neural restructuring. Thereafter, a slower consolidation phase begins, requiring repeated practice under real fatigue and stress conditions to automate strategies so they remain reliably accessible at critical moments in competition. Understanding this timeline helps avoid abandoning the approach prematurely when immediate effects are not yet visible.

The table below summarizes expected effects across different intervention doses (median estimates compiled from multiple studies; individual variability is high):

Intervention Dose	Duration	Exercise Addiction Improvement	Performance/Psychological Benefit	Evidence Strength
Low (1 practice session/week)	4 weeks	+2%	Minimal	Moderate
Medium (2–3 sessions/week)	8 weeks	+12%	Noticeable	High
High (daily integrated practice)	12 weeks	+20%	Significant and stable	Moderate–High
Excessive/Inappropriate (over-monitoring)	—	Counterproductive/increased anxiety	Negative	Moderate

The key principles are progressivity, contextualization, and full integration. Unlike physiological adaptation, psychological skills must be practiced in real “stressful, fatiguing” contexts to transfer to competition—meditation or imagery practiced purely in a relaxed state is unlikely to activate automatically at the point of exhaustion. Research also cautions that excessive self-monitoring (e.g., constantly checking whether you are “focused enough”) can consume cognitive resources and generate new anxiety—a common overuse trap in exercise addiction applications.

Furthermore, “effects” must be distinguished between immediate performance and long-term psychological well-being, which are not always aligned. Certain strategies that immediately extract performance (e.g., extreme fear-of-failure motivation) may undermine motivation and well-being in the long run, requiring coaches to weigh trade-offs carefully rather than chasing short-term numbers.

Differences Across Populations

The “optimal application” of exercise addiction is not one-size-fits-all; it varies significantly with individual characteristics. Applying a single template while ignoring population differences is the most common mistake in amateur psychological training.

Beginners vs. Advanced Athletes: Beginners’ exercise addiction is typically less stable and more susceptible to external distractions and self-doubt, so they benefit most from foundational confidence-building and positive self-talk. Advanced athletes already possess a baseline of psychological skills and need more refined, context-specific strategy adjustments—such as shifting attentional focus at specific phases of competition. Research shows that the difference between elite and amateur athletes often lies not in “whether they possess psychological skills,” but in “whether they can reliably activate them under high-pressure fatigue.”

Gender Differences: Studies indicate average differences between men and women in the expression of anxiety, emotion-regulation preferences, and social support needs. Female athletes in some studies report higher cognitive anxiety but also make better use of social support and emotional expression strategies; males tend to favor problem-focused coping. These differences remind us that psychological prescriptions should account for individual preferences rather than applying gender stereotypes.

Age Differences: With age, emotion-regulation capacity and experiential wisdom typically improve, but sensitivity to digital social comparison, recovery needs, and sources of motivation also change. Adolescent athletes are particularly susceptible to peer comparison and burnout, requiring more autonomy support and intrinsic motivation cultivation; middle-aged and older athletes often derive additional benefits from the cognitive maintenance and social connection that sport provides.

The table below outlines adjustment priorities across populations:

Population	Exercise Addiction Characteristics	Psychological Training Focus	Risk Considerations
Beginners	Unstable, prone to self-doubt	Confidence and positive self-talk	Excessive comparison
Advanced	Has foundation, needs refinement	Context-specific strategy switching	Over-analysis
Female	Higher cognitive anxiety	Social support and emotion regulation	Applying stereotypes
Adolescents	Susceptible to peer influence/burnout	Autonomy and intrinsic motivation	Premature specialization burnout
Middle-aged/Older	More mature emotion regulation	Cognitive maintenance and social connection	Insufficient recovery

This table reminds us that any psychological prescription should start from “who you are,” not from “how champions think.”

Practical Training Application

Theory that cannot be implemented is merely armchair speculation. Below is an actionable framework to translate academic findings on exercise addiction into daily training and competition preparation.

Step 1: Objectively Assess the Current State. Before any intervention, quantify your psychological baseline. Even without laboratory equipment, HRV monitoring from a sports watch, standardized psychological scales (such as the Competitive State Anxiety Inventory CSAI-2 or sport psychological skills inventories), and training logs provide sufficient reference baselines. Without measurement, there is no management.

Step 2: Set a Single Psychological Goal. Focus on only one skill at a time. Trying to simultaneously improve concentration, anxiety control, and self-talk makes it impossible to determine what works. A 6-week psychological training cycle focused on deepening one skill to automation is recommended.

Step 3: Practice Progressively in Context. Below is an example weekly structure:

Week	Practice Context	Focus	Monitoring Indicator
1–2	Static/low intensity	Learn the technique, build feel	Subjective mastery
3–4	Moderate-intensity integration	Maintain activation under fatigue	RPE and mood
5	Simulated pressure situations	Stable application under high stress	Anxiety scale
6	Near-competition testing	Transfer to real performance	Performance indicators

Step 4: Integrate into Daily Routines. Improvements in exercise addiction often require embedding into existing warm-up, nutrition, and sleep routines—becoming automated “routines” rather than additional burdens. Anchoring breathing regulation, self-talk, or imagery practice to fixed triggers (such as the start line or each aid station) can substantially increase automatic activation at critical moments.

Step 5: Reassess and Iterate. After the cycle ends, re-measure, compare against baseline, and decide the next step. Remember individual differences—what works for others may not work for you. Objective data and bodily sensations must be weighed together; neither is dispensable.

Local Application in Taiwan

Taiwan’s unique climate, terrain, and sports culture add distinctive variables to the application of exercise addiction mechanisms—particularly the phenomenon of overtraining cyclists.

Psychological Amplification Effects of Hot, Humid Climate: Taiwan’s summer heat and humidity raise core body temperature, accelerating physiological fatigue and amplifying perceived exertion, making psychological strategies even more critical. The aforementioned research identifies perceived exertion as the key determinant of whether one gives up, and in Taiwan’s hot, humid long-distance events, this sense of effort is significantly magnified. It is recommended to schedule high-quality psychological skill practice and key workouts during cooler morning or evening hours, and to rehearse “self-talk and attentional strategies under heat” in advance during training, so that race-day psychological collapse in high temperatures does not disrupt your rhythm.

Targeting Local Contexts: The overtraining cyclist phenomenon is the most common psychological scenario Taiwanese athletes face. Whether it is the long solitude of a steep climb, the monotonous grind of headwinds along riverside paths, or the anxiety of wave-start mass events, each places specific demands on exercise addiction. Designing psychological rehearsals for these concrete situations—such as practicing segmented goal-setting and self-talk during a Wuling climb—is often far more effective than abstract “mental toughness” advice.

Community Culture and Resources: Taiwan’s thriving cycling team and running club culture provides an excellent arena for social support and collective psychological training. Leveraging group dynamics can amplify self-efficacy and persistence; however, social platforms (such as Strava) can also generate pressure and anxiety through social comparison. Athletes are advised to return to the evidence-based framework in this article, harness the positive supportive functions of community, while remaining vigilant against the psychological trap of excessive comparison.

Common Myths Debunked

Myth 1: “Exercise addiction is willpower—something you’re born with and can’t be trained.” Wrong. Numerous RCTs and longitudinal studies confirm that exercise addiction is a psychological skill that can be improved through systematic training, with a clear basis in neuroplasticity. It is not a fixed, innate trait.

Myth 2: “Mental training is only for the weak.” Wrong. Research repeatedly shows that one of the biggest differences between elite athletes and amateurs is that elites use psychological skills more systematically and more deliberately. Viewing mental training as a sign of weakness is precisely the biggest competitive disadvantage.

Myth 3: “If you want it badly enough, you can overcome anything.” Partially true but overstated. Motivation matters, but relying excessively on excitement or fear of failure as a driving force will, over the long term, harm well-being and sustainability. Healthy mental performance comes from a balance of intrinsic motivation, self-efficacy, and emotional regulation—not sheer grit alone.

Myth 4: “Feeling relaxed means you’re in a good mental state.” Subjective feelings matter but cannot be fully trusted. Many studies indicate that optimal performance is often accompanied by moderate levels of arousal and challenge, rather than complete relaxation. Over-chasing relaxation may instead trap you in a state of insufficient arousal and low engagement. Only objective measurements (such as HRV or anxiety scales) can puncture the illusion of the comfort zone.

Conclusion

The science of exercise addiction mechanisms tells us that exercise addiction is not an abstract concept that can be summed up by “just have the right mindset.” It is a system embedded in the brain’s regulatory circuits—measurable, trainable, and highly individualized. Research from scholars such as Karageorghis, Tucker, and Masters repeatedly confirms three core principles—psychological benefits are real and measurable, individual differences dominate, and mechanisms matter more than slogans.

For athletes in Taiwan, real progress comes from patiently translating laboratory evidence into mental training decisions that fit your own body, your own routes, your own climate, and your own culture. Rather than chasing motivational quotes and quick fixes on social media, it is better to establish a measure–intervene–re-evaluate scientific cycle, and—amid the real-world phenomenon of overtraining among fellow cyclists—accumulate your own mental resilience and peak performance state week by week.

Sport psychology is not about turning competition into a cold numbers game; it gives us a clearer pair of glasses to see how the brain makes choices among fatigue, stress, and desire. When scientific evidence and bodily sensations move in sync, performance breakthroughs and long-term mental health can truly go hand in hand. This is precisely the most valuable insight that research on exercise addiction mechanisms offers to every sports enthusiast in Taiwan.

Related Reading

• Post-Endurance Exercise Mood Enhancement: A Mechanistic Study of Endocannabinoids vs. Endorphins
• The Effectiveness of Pre-Competition Mental Preparation Strategies: A Comparative Study of Imagery Training vs. Relaxation Training
• Burnout Syndrome in Adolescent Athletes: A Research Review of Prevalence and Prevention
• The Effectiveness of Visualization Training on the Rate of Motor Skill Acquisition: A Neuroscientific Validation Study