This study explores whether a peer-supported "fitness buddy" program can help first-year university students increase physical activity levels and improve mental well-being. Over 12 weeks, participants will form small exercise groups, choose enjoyable activities (such as jogging, cycling, or yoga), and support each other through shared goals and regular check-ins. A professional coach will offer weekly guidance on exercise safety, injury prevention, and motivation strategies, but the actual workouts will be conducted by the students.

The investigators aim to determine if this peer-based approach helps reduce stress, anxiety, and depressive symptoms, while boosting self-esteem and social connectedness. Students in a control group will receive usual campus resources without structured group support. By comparing outcomes at the start, after the 12-week program, and again at follow-up, the study will assess whether peer-led, knowledge-supported exercise can sustainably enhance both physical and mental health during the critical transition into university life.

This longitudinal, parallel-group study focuses on first-year undergraduates (ages 18-25) who are not currently engaged in structured exercise programs. Participants meeting inclusion criteria will be assigned to either a peer-supported exercise group (with weekly professional guidance) or a control group (usual campus resources, no structured group sessions). The peer-support model encourages accountability, shared goal-setting, and regular communication via group messaging tools.

Data collection will include physical activity levels (e.g., International Physical Activity Questionnaire), mental health outcomes (GAD-7, PHQ-9), perceived stress (PSS), self-esteem (RSES), loneliness (UCLA Loneliness Scale), and social connectedness (SCS). Assessments occur at baseline, 12 weeks (post-intervention), and at a short-term follow-up (Week 16) to evaluate both immediate and sustained effects. All participants will receive instructions on safe exercise practices. Potential risks, such as minor injuries or discomfort discussing mental health, will be minimized through clear guidance, optional campus support resources, and respect for privacy. The findings may help universities develop targeted programs that combine knowledge-based coaching with peer support to enhance students' physical and psychosocial well-being.

Inclusion Criteria

1. First-year undergraduate students (ages 18-25) enrolled at the university.
2. Able to safely participate in moderate-intensity exercise as determined by a pre-screening health questionnaire.
3. Willing to join a 12-week, peer-supported exercise program and complete all baseline, post-intervention, and follow-up assessments.

Exclusion Criteria

1. Documented medical conditions that preclude safe engagement in moderate-intensity physical activity (e.g., severe cardiovascular disease, uncontrolled hypertension).
2. Current major psychiatric disorders (e.g., psychotic disorders) that could significantly impede adherence to the study protocol.
3. Enrollment in any structured exercise program (≥3 sessions per week) for at least 3 consecutive months prior to study entry.

De-identified individual participant data (including demographic information and outcome measures) will be made available to qualified researchers upon reasonable request. A data use agreement (DUA) must be signed, and approval from our institutional ethics committee may be required. Data will be made available after publication of the primary findings and for up to 5 years thereafter.