Brief Mental Strength Scale: Development, Factorial Validity, and Psychometric Properties in Combat Sports

Background: Mental strength is defined as the behavioral capacity to persist through obstacles and challenges, and to recover from failures, adversities, and setbacks. Building on previous scale developments, Studies 1 and 2 aimed to develop, refine, and validate a brief, psychometrically robust measure of mental strength for combat sports practitioners. Methods: In Study 1, an exploratory factor analysis (EFA) was conducted on a sample of Brazilian jiu-jitsu practitioners (N = 328) to evaluate the factor structure of the 9-item Mental Strength Scale and to propose a brief version of the Mental Strength Scale. In Study 2, a confirmatory factor analysis (CFA) was performed on a separate sample of combat sports practitioners (N = 300) to test the factor structure of the newly derived Brief Mental Strength Scale (BMSS). Additionally, Study 2 assessed internal consistency and predictive validity against measures of self-efficacy, self-control, self-esteem, and symptoms of anxiety and depression. Results: In Study 1, EFA results championed a two-factor structure, leading to the removal of 3 items. In Study 2, CFA confirmed good fit for the two-factor, 6-item model (subscales “Dealing with Failure” and “Facing Obstacles”), showing excellent fit indices: CFI = .985, TLI = .972, SRMR = .037, RMSEA = .090. The scale demonstrated strong internal consistency (α = .89). Moreover, the BMSS exhibited significant (p < .001) and robust predictive validity, positively predicting self-efficacy (β = .66), self-control (β = .51), and self-esteem (β = .45), while negatively predicting symptoms of anxiety (β = -.39) and depression (β = -.38). Conclusion: The Brief Mental Strength Scale is a valid, reliable, and structurally sound bidimensional instrument for assessing mental strength among combat sports practitioners, offering coaches and sport psychology professionals a practical tool for monitoring and enhancing well-being and performance.