Background: Complex learning dynamics exist in ecologically valid collaborative learning environments, such as medical simulation training. Although medical scenarios are known to elicit emotional responses, the role of these emotions in shaping team performance is often overlooked. Physiological synchrony (PS) offers a promising lens to explore these emotional dynamics and, when integrated with multimodal learning analytics, can enhance our understanding of collaborative processes in medical teams, including the team leaders’ performance. Theoretical framework: This study was guided by socially-shared regulated learning and the control-value theory of achievement emotions. We used these theories to operationalize and situate physiological arousal as an emotional expression component, draw insight from the context simulation training occurred in, and interpret findings. Aims: To examine PS among medical residents undergoing crisis resource management (CRM) simulation training and explore its relationship with team leaders’ performance. Sample: Participants were 29 medical trainees grouped into 9 teams participating in team-based simulations. Methods: A field-based, quantitative approach was employed. Electrodermal activity (EDA) was used to assess participants' emotional arousal, and Multidimensional Recurrence Quantification Analysis (MdRQA) was used to evaluate PS. Team leaders’ performance was scored using the Ottawa Global Rating Scale. Results: PS was observed among team members during both pre-simulation and simulation phases. Preliminary results revealed that PS was positively correlated with team leader performance. Conclusion: Findings offer novel insights into the existence and role of PS in ecologically-valid team-based medical simulation education. PS may reflect important aspects of teams' emotional arousal and, while preliminary, team leaders’ performance.