The aim of this study was to evaluate the cumulative impact of supervision on technical skills and surrogate stress markers in surgical trainees. This was a quasi-experimental crossover study to evaluate the impact of attending supervision on orthopedic trainee stress response during a simulated surgical procedure. Enrolled residents performed a proximal femoral nail module with the Precision OS system twice; once independently, and once under direct attending supervision, whilst wearing a heart rate monitor. Mean and maximum heart rates were recorded. Simulated performance was assessed using validated simulator-based metrics. Student's t-test was used to evaluate the impact of supervision on trainee heart rate, and performance ranking. Tertiary trauma center in a Regional Orthopedic Unit PARTICIPANTS: Orthopedic interns and residents within our institution were invited to participate, with 20 participants included for analysis. Both supervised and unsupervised mean heart rate was significantly higher (p = 0.001) than baseline recorded heart rates. Supervised mean and maximum HR were significantly higher than unsupervised HR during module completion (p = 0.015; p = 0.001). Calories burned demonstrated correlation to surrogate stress markers, significantly higher in supervised sessions (p = 0.004). Performance metrics demonstrated superior performance in senior-level participants, with a decrement in performance during supervision, failing to reach significance. The development of accretion of technical and non-technical skills required in surgical training pathways may derive benefit from the use of simulation-based training in surgical residents with both supervised and unsupervised sessions.