AI-Supported Digital Coaching And Cardiorespiratory Fitness In Male University Students

This was a single-center, parallel-group randomized controlled trial conducted at Transilvania University of Brașov, Romania. Participants meeting the study-defined semi-active criteria were randomized 1:1 to AI-supported digital coaching or standard Samsung Health-based activity monitoring.

The experimental intervention combined activity monitoring with adaptive digital coaching. Coaching outputs included personalized daily step targets, activity coaching and goal adjustment, weekly progress summaries, and recovery or rest-day recommendations based on recent activity. Android participants received the configured intervention through the research Samsung Health environment. For participants using iOS devices, activity data were incorporated through the study workflow using Apple HealthKit where necessary, and equivalent coaching was delivered through a research-administered web dashboard.

Participants in the control group used standard Samsung Health monitoring, including step counting, activity displays, and generic weekly reports, without the research-configured AI-supported coaching. No study-provided individualized exercise program was delivered to either group.

Cardiorespiratory fitness was assessed using estimated VO2max derived from distance completed during the Cooper 12-minute test. Physical activity was monitored using daily step counts. The trial was designed to compare cardiorespiratory fitness and physical-activity trajectories between the randomized groups.

Inclusion criteria

• Male university student.
• Average of 5,000-7,499 steps/day over the last 14 valid pre-baseline activity-monitoring days available through the study workflow.
• Self-reported moderate-to-vigorous physical activity of 150-299 minutes/week on the International Physical Activity Questionnaire-Short Form (IPAQ-SF).
• Completion of the Physical Activity Readiness Questionnaire for Everyone (PAR-Q+); participants with an affirmative response were required to obtain medical clearance before enrollment.
• Written informed consent provided before baseline assessment and randomization.

Exclusion criteria

• Did not meet the study-defined semi-active physical-activity criteria, including participants who were already highly active.
• Medical contraindication to participation or failure to obtain required medical clearance following safety screening.
• Planned absence of more than 2 weeks during the study period.