Overactivation of the Reward System and Deficient Inhibition in Exercise Addiction

Abstract

Purpose Behavior studies have found that exercise addiction is associated with high impulsivity. In other addictions, neural mechanisms of impulsivity reflect abnormalities in the reward and inhibition systems. In this study, we determined whether abnormalities existed in the reward and inhibition systems of exercise addicts. Methods Three groups of male participants (15 exercise addicts, 18 regular exercisers, and 16 exercise avoiders) completed the Mini International Personality Item Pool (Mini-IPIP), the classic go/no-go task, and the exercise-related go/no-go task. Event-related potentials (ERP) were recorded during the go/no-go tasks, and correctly performed trials were analyzed. Results Exercise addicts scored lower for extraversion and higher for neuroticism, reflecting a poor capacity for emotional regulation and impulse control, and had larger N2 and P3d amplitudes during the exercise-related go/no-go task. Exercise addicts and exercise avoiders demonstrated impaired accuracy in the exercise-related go/no-go task and had larger N2 amplitudes compared with regular exercisers during the letter–digit go/no-go task. Exercise addicts and regular exercisers showed larger Go-N1 and Go-P2 amplitudes compared with exercise avoiders during the exercise-related go/no-go task. Exercisers (exercise addicts and regular exercisers) demonstrated higher activation in response to exercise-related stimuli as reflected by larger N1 and P2, and addicts (exercise addicts) demonstrated poorer inhibition as reflected by larger N2 and P3d amplitudes. Go-N1 and Go-P2 were significantly correlated with no-go accuracy in exercise-related task. Conclusions Exercise addicts scored higher for the neuroticism personality trait and exhibited overactivation of the reward system and underactivation of the inhibition system. Overactivation of the reward system may be related to long-term exposure to exercise. Underactivation of the inhibition system may be a crucial factor in exercise addiction.

Emotion dysregulation mediates the relationship between psychological distress, symptoms of exercise addiction and eating disorders: A large-scale survey among fitness center users.

“…Although the current findings are based on a cross-sectional design, which is inappropriate for establishing any casual relationships, we assume that an increased risk of exercise addiction might be a result of the interface between psychological distress and emotional dysregulation. Our findings and proposition are in line with some current neurophysiological results using cognitive tasks (Huang et al, 2019). Using Go/No-go tasks in regular exercisers, exercise addicts, and exercise avoiders, the authors confirmed an overactivation of the reward system of the individuals in the exerciser groups.…”

Exercise addiction and COVID-19-associated restrictions

“…Abnormalities in reward and inhibition systems are found in exercise addicts, which may explain their impulsivity, loss of control, and interference in decisionmaking. In addicts' brains, reward system overactivation is revealed by enhanced activities in the prefrontal, limbic, and striatal areas, while an impaired inhibition system is reflected by lower N2 and P3 amplitudes in the orbitofrontal-dorsolateral cortices (Huang et al, 2019). These individuals have to exercise more to trigger chemical release which describes reward-seeking behaviour.…”

Narcissism and Exercise Addiction: The Mediating Roles of Exercise-Related Motives

“…It seems reasonable to assume these characteristics may contribute to the development of exercise addiction. In addition, narcissistic vulnerability is similar to the basic personality dimensions of neuroticism [ 64 ] which has been found to be associated with exercise addiction [ 15 , 25 , 65 , 66 ].…”