Background: This article presents the protocol for a randomised controlled trial designed to develop and evaluate a psychoeducational intervention aimed at preparing high-performance athletes for the challenges and opportunities presented by the transition to retirement from sport. The protocol was developed through a literature review and consultations with experts in sports psychology and career transition.

Methods: The study will be conducted at the Faculty of Psychology of the University of Salamanca (Spain). High-performance athletes aged 30 or older who are close to retirement or who have retired in the last five years will be recruited. Participants will be randomly assigned to two groups: the intervention group, which will undergo a psychoeducational programme consisting of 12 sessions over 3 months; and the control group, which will receive a minimum educational programme of one session. All participants will complete initial and final assessments, as well as a 3-month follow-up, collecting sociodemographic data and applying various psychological, social and health assessment instruments.

Discussion: This protocol describes a comprehensive psychoeducational intervention aimed at improving quality of life and attitudes towards retirement from sport, increasing life satisfaction, psychological flexibility, perceived social support, general health, self-efficacy and self-regulation, and reducing negative stereotypes associated with the end of a sporting career. The evidence generated will guide future interventions, policies, and educational programmes to promote a healthy, active, and satisfying transition to the post-sport stage.

Inclusion Criteria:

• Participants will be included if they are within the critical transition period, defined as:

Five years prior to sports retirement, when the first signs of preparation and emotional anticipation begin.

Five years after retirement, the stage in which identity, psychological, and professional adaptation processes are consolidated.

This interval reflects the progressive nature of adaptation to sports retirement.

Exclusion Criteria:

• Athletes presenting any of the following conditions will be excluded from the study:

Significant literacy difficulties or relevant deficits in linguistic comprehension that prevent adequate participation in the psychoeducational sessions or the completion of assessment instruments.

Severe unstabilized medical or psychological conditions that may interfere with the normal development of the program (e.g., untreated severe depressive episodes, limiting neurological disorders).

Failure to meet the inclusion criteria, specifically not being within the five-year period prior to or after sports retirement or failing to verify high-performance sports experience.

Refusal to sign the informed consent or lack of availability to regularly attend the program sessions.

They will be made available to researchers in the document repository "GREDOS" of the University of Salamanca, Spain.

Data will be available at the end of the study.

Open access for researchers.

The work of sequencing, randomisation, recruitment and allocation of the trial sample will be carried out by research staff who are not involved in the assessments or interventions of each group, thus avoiding any potential bias in the trial.

Participants will also be blinded and will not know which group they have been allocated to and therefore which intervention they will receive. In order to minimise any contamination between groups, the assessment process will be carried out by external research staff who will perform the measurements and who have been previously trained and educated to avoid subjective bias in the process, as they will be unaware of the intervention group to which they have been assigned, thus masking the blinded assessment by third parties in the clinical trial. In addition, the researchers responsible for the statistical analysis of the trial will be blinded in order to increase the rigour of the trial process and thus the scientific quality.