Engagement is one of the core concepts in the field of positive psychology. It refers to the sustained mental state of an individual filled with positive emotions. It is an essential factor in influencing an individual's behavioral performance and the direction of behavioral development1. Lonsdale et al.2,3 first introduced the concept of athlete engagement in the field of competitive sport, which is characterized by self-confidence (belief in one's ability to achieve a high level of performance and desired goals), dedication (desire to invest energy and time in the achievement of personally important goals), vitality (a state of feeling of being physically and psychologically energized), and enthusiasm (the experience of a strong sense of arousal and pleasure). Athlete engagement is an important indicator of athletes' positive psychology, which can reflect athletes' positive and healthy psychological state, and is conducive to stimulating athletes' positive qualities such as optimism, perseverance, creativity, etc., so as to effectively promote the development and maturity of athletes, and to lay a solid foundation for them to enhance their athletic ability and to improve their athletic performance4. Comprehensively exploring the factors affecting athlete engagement helps to scientifically and systematically grasp the changes and developmental laws of athlete engagement. It provides theoretical references for stimulating athletes' potential and improving sports performance. External factors such as group cohesion4, motivational climate5, and coach-athlete relationship6 and internal factors such as perfectionism7, basic psychological needs8, and self-concept9 are essential factors influencing athlete engagement. In addition, work and learning engagement studies have demonstrated that social support is a significant predictor of individual engagement10.
Adolescent athletes are an important reserve resource for the sustainable development of a country's sports. At the same time, young athletes are a particular group. On the one hand, adolescent athletes are in a high-intensity training environment for a long time and must withstand many external pressures, such as coaches' harshness and external expectations. On the other hand, young athletes are in a sensitive period of sports level and physical and mental development, which is a critical stage to improve sports performance and become elite athletes11. Therefore, this study explores the effects of social support on adolescent athletes' engagement with adolescent athletes as subjects. Based on this, it explores the internal mechanism of action of athlete engagement, aiming to provide a valuable reference basis for adolescent athletes' engagement intervention practice.
Social support refers to the moral and material comfort, care, respect, and help given to an individual by various social parties such as family, relatives, and friends10. Athletes, as a high-pressure group, are constantly exposed to stressors such as training, competition, injuries, etc. They experience a higher sense of belonging and security when they have more social support. They can receive adequate advice and guidance from others to improve their athletic skills, competence, and confidence4. A study of Olympic athletes shows that high levels of social support are necessary for athletes on the road to success12. Athletes' perceived social support can be categorized in terms of type into emotional support (meaning that others accompany and care for the individual to enhance his or her sense of security and comfort), respectful support (which is when others help the individual to enhance his sense of competence and self-esteem), informational support (which means that others provide the individual with advice and guidance on relevant issues), and tangible support (which refers to substantial help such as money, services, and sharing of responsibilities)12. Social support can be categorized as coaching, parental, and peer support13. Coaches are recognized as the primary providers of social support for athletes, and their social support is critical to their growth and development 12. Improving the support provided by coaches may help create a harmonious sporting environment, allowing for quicker allocation of resources and an improved sporting experience for athletes14. Parental encouragement and the level of emotional and respectful support shown to adolescent athletes can effectively mitigate the negative effects of stressors present in the athletic environment on self-confidence and athletic performance15. Peer support promotes positive emotions, reduces mental fatigue, and enhances athlete engagement during athletic training and competition16. Based on this, this research proposes hypothesis H1: Social support can positively predicts adolescent athlete engagement.
Self-efficacy refers to an individual's assumptions and judgments about their ability to perform a behavior17. Typically, the more robust an individual's sense of self-efficacy and outcome expectations, the more likely they are to start and persist in a particular activity18. Self-efficacy is a crucial psychological factor for athletes. Athletes encounter a variety of pressures at any time during training and competition, and how to properly understand each other and master effective solutions depends on the level of individual self-efficacy19. From the self-efficacy perspective, a positive subjective assessment of an individual can impact the level of interest and commitment to engage in a specific activity, which can play a decisive role in determining an individual's behavioral choices20. During exercise, individuals with higher self-efficacy make a subjective assessment of their effectiveness in accomplishing the activity prior to the action, and this pre-estimation has a significant impact on regulating the athlete's mood and facilitating commitment to the game21. In addition, obtaining more social support can promote adolescents' self-efficacy, and social support can positively and positively influence self-efficacy22. According to self-efficacy theory, social persuasion, vicarious experience, and emotional state are the main factors that affect an individual's self-efficacy17. Social support can help individuals experience more success and thus increase self-efficacy23. In the process of training or competition, coaches' encouragement and guidance to the athletes play a function of social persuasion to a certain extent. The training feelings, experience sharing, and communication among peers help form the athletes' alternative experiences, and parents' support and understanding of the athletes' participation in training can help enhance the athletes' emotional state of participation in training. In other words, a favorable social supportive environment can help individuals improve their confidence in training and competing and improve athletes' self-efficacy. Based on this, this research proposes hypothesis H2: Self-efficacy plays a mediation role between social support and athlete engagement.
Psychological resilience is the ability or trait of an individual to cope with adverse life events such as stress, frustration, and trauma24. Athletes need mental toughness to achieve athletic excellence in training and competition25. Because of this, mental toughness is viewed by athletes, coaches, and researchers in athlete psychology as one of the most important psychological traits for athletes to be successful in competition26. On the one hand, mental toughness is significantly and positively correlated with an individual's athletic performance, with athletes high in mental toughness participating at higher levels of competition, having better performances in competitions, and achieving more success 27. Athletes with high mental toughness have higher control beliefs about stressful situations, tend to evaluate stressors as challenges rather than threats, have higher coping efficacy, and adopt more coping strategies focused on solving realistic problems28. On the other hand, athletes with high mental toughness are less likely to experience negative emotions. A longitudinal follow-up study of adolescent athletes showed that mental toughness effectively reduced physiological and emotional exhaustion, reduced mental fatigue overall, and demonstrated sustained impact effects29. In addition to the protective effects in stressful situations, relevant studies have found that mental toughness has significant gainful functions, such as attentional control, goal orientation, and fluency states30. Athletes with high mental toughness make more positive and accurate cognitive evaluations of the individual and engage in a more proactive attitude toward training and competition31. At the same time, an individual's level of mental toughness is not static. In addition to innate genetic factors, enhancement through later life is equally important. Previous research has shown that social support is essential to mental toughness32. Comprehensive and diversified social support is of great relevance in improving athletes' mental toughness33, increasing athletes' problem-solving strategies, but also by decreasing athletes' risk appraisal of adversity34. Based on this, this research proposes hypothesis H3: Mental toughness mediates between social support and athlete engagement.
Related research has confirmed that self-efficacy significantly predicts levels of mental toughness35. A high level of self-efficacy helps individuals cope with stress and frustration with good mental toughness, thus developing a sound personality and forming a healthy psychology36. A study of elite marathon runners showed that self-efficacy was closely related to mental toughness, with athletes with higher efficacy having better mental toughness37. According to the Goal-Expectation-Self-Control model, self-efficacy is considered an essential component of psychological resilience38, and many studies have demonstrated its contribution to psychological resilience39. An individual with a high sense of self-efficacy will inspire greater confidence and courage to face adversity or setbacks and face changes in the environment with a positive attitude. Because of this, individuals with a high sense of self-efficacy can further increase their level of mental toughness as they proactively cope with a variety of problems40. The relationship between self-efficacy and mental toughness is perhaps related to endogenous opioid activation41. Related studies have noted that endogenous opioids relieve pain, self-efficacy can cause endogenous opioid activation and mental toughness is associated with pain tolerance. Athletes may experience higher levels of mental toughness because they have a stronger sense of self-efficacy to relieve pain through the body's endocrine system42. Based on this, this research proposes hypothesis H4: Self-efficacy and mental toughness mediate between social support and athlete engagement. The hypothesized model of this study is shown in Fig. 1.