Introduction

Volleyball is a team sport that requires high physical and perceptual-cognitive fitness, therefore, during the competition, an increase in the feeling of physical and mental fatigue is observed among the players. Psychological skills refer to the inherent or learned characteristics of the athlete that make his success possible or probable. Wingberg and Gold have introduced psychological factors as the first reason for day-to-day fluctuations in sports performance. Jay proposes two types of complete performance and relative performance. He believes that perfect performance refers to a person's optimal mental performance; In this way, it is not possible to achieve full performance in competitive sports, and factors potentially affect the player's performance. In this regard, Jay refers to two categories of physiological and psychological inhibitory factors; Therefore, if the level of psychological skills of players is high, they can actively control and reduce the negative effects of psychological inhibiting factors and maximize their relative performance for a specific competition. In most cases, researchers and psychologists focus on the negative roles of sports psychology such as stress, anxiety, anger, aggression, and mental disabilities on the performance of athletes, and less attention has been paid to human capabilities based on mental toughness. Today, mental toughness plays a positive role as an important variable in achieving sports results and is one of the main requirements for the success of athletes. Mental toughness is directly related to the personality and fighting spirit of athletes; A person with high mental toughness is expected to perform better than others in high-pressure competitive situations by overcoming stress and competitive atmosphere. Mental toughness is considered as a psychological characteristic and one of the contributing and effective factors in the success of sports performance in all athletes and at all levels. The purpose of this research is to investigate the effect of mental toughness on volleyball athletes in league competitions.

Method: The research design and implementation method were experimental, and the sampling method was implemented randomly. The statistical population of this research was the volleyball athletes of the Ifa and Chadormelo teams of Ardakan city in 2023, whose sports performance is measured in different parts during a competition season. The number of these people was 42. These 42 athletes were from 2 top league teams participating in Iran's 2023 season. The minimum sample size in correlational studies is 30 people. The sample size was estimated based on Cochran's formula. Based on Cochran's formula, a sample of 38 people is required and estimated for a limited population with 42 people. With the possibility of dropping out, all 42 people were selected as a statistical sample. The sampling method was done in convenient sampling method. The research tools were mental toughness and sports performance questionnaires. Finally, the data were analyzed using Pearson's chi-square method and SPSS software version 27.

Results: The results of the research showed that there is a positive and significant correlation between psychological toughness and sports performance. 9.3 percent of the variance of performance/ Also, among the components of tenacity, the fighting component explained a significant predictor of sports performance. The findings showed that mental toughness athletes have better performance. Therefore, evaluating and strengthening mental toughness can be practical in intervention planning to increase performance.

Conclusion: Finally, the results of examining the role of the mediator variable showed that mental toughness has a significant effect on sports performance through the creation of a skill including (1) Control: the individual's tendency to believe they can influence their life and emotions; (2) Commitment: the persistence in pursuing goals despite difficulties; (3) Challenge: viewing potential threats as opportunities for personal growth. The results of the research showed that mental toughness has a positive effect the number of services leading to points, the number of passes leading to points, the number of points received, the number of personal fouls, points leading to defense on the net, points leading to backcourt defense, and the number of spikes. Therefore, People with high mental toughness usually have a higher ability to deal with mental and physical pressures. This can improve the performance of volleyball players during the game and, as a result, increase their points. Mental toughness can play a role as an effective factor in improving players' focus and attention. People with high mental toughness usually have a higher ability to maintain concentration and pay attention to the game, which can improve their performance and, as a result, the number of services leading to points, the number of passes leading to points, the number of points received, the number of errors Personal, points leading to net defense, points leading to backcourt defense, number of spikes help more. Therefore, it is clear that mental toughness plays an important role in the performance of volleyball players and can improve the number of serves leading to points, the number of passes leading to points, the number of points received, the number of personal fouls, points leading to net defense, points leading to The backfield defense, the number of their spikes will help. Therefore, training and developing mental toughness can be used as an effective strategy to improve the performance of volleyball players.

Research limitations:

Among the limitations of this research is the lack of control over the stressful conditions of the subjects outside of training, the limitedness of the examined sample and as a result the problem of generalizing it to other athletes in different disciplines, the existing research gap in relation to the study of the research variables, the research sample. It was related to the city of Ardakan, Yazd, and according to cultural and social factors, this case may be effective in generalizing the results at the national level and other groups. In the present study, variables such as social class, educational status, etc. It is one of the influential factors, which may have influenced the results, so it is suggested to use each person's favorite music in future research.

Keywords: Mental Toughness, Players' Performance, Results, Volleyball.

Ethical Considerations

Compliance with ethical guidelines

The ethical principles observed in the article, such as the informed consent of the participants, the confidentiality of information, the permission of the participants to cancel their participation in the research. Ethical approval was obtained from the Research Ethics Committee of the University of Qom.

Funding

This study was extracted from the thesis of first author.

Authors' contribution

All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.

Conflict of interest

The authors declared no conflict of interest.

Acknowledgements

The authors would like to thank all participants of the present study.