Effectiveness of an online emotional intelligence training among athletes: Do defense mechanisms matter?

• Adaptive defense mechanisms (ADM) increased throughout the entire EI training. • Maladaptive defense mechanisms (MDM) decreased following EI training. • Online EI training was associated with changes in trait EI and neuroticism over time. • High MDM predicted slower EI growth and lower agreeableness and conscientiousness. • High ADM predicted higher trait EI, higher agreeableness, and lower neuroticism. This study examined changes associated with participation in an online emotional intelligence (EI) training program (API-D) and explored how defense mechanisms predict changes in EI and personality traits throughout the intervention. A total of 96 athletes (67 women) participated in this study; a training group ( n = 50) received the 8-week, two-phase API-D online program, while a control group ( n = 46) did not. All athletes completed self-report measures of defense mechanisms, trait EI, and personality traits at three measurement points: before the intervention, after phase one (knowledge development phase), and after phase two (abilities development phase). For the training group, repeated measures ANOVAs showed an increase in adaptive defense mechanisms (ADM) and a decrease in maladaptive defense mechanisms (MDM). Multilevel Growth Curve Analysis revealed a linear increase in the global score of trait EI and a linear decrease in neuroticism throughout the intervention. Findings also indicated that defense mechanisms influenced the trajectories of trait EI and personality traits. Participation in the API-D program was associated with increases in trait EI, reductions in neuroticism, and more adaptive defensive functioning across the intervention. ADM were associated with higher trait EI, suggesting that they foster psychological readiness for EI learning. In contrast, MDM predicted lower EI and showed slower improvement over time, underlining their potential role as barriers to EI development during training. Overall, these findings highlight the role that defense mechanisms as psychological processes may play, as they can either facilitate or hinder athletes’ EI development.