Impact of exam stress and time of day on hand grip fatigue in medical students

Summative examinations are essential in medical education, but often provoke stress that can impair cognitive and physical performance. This study examined whether exam-related stress affects muscle function by comparing hand grip strength and fatigue on exam versus non-exam days. First-year medical students at ICOM completed three maximal grip trials using a Vernier Hand Dynamometer during four sessions: morning exam and non-exam, afternoon exam and non-exam days. At each session, participants were instructed to squeeze the dynamometer with maximal effort and to maintain peak force for 30 s. Data was analyzed in GraphPad Prism and R, with outcome measures including slope, maximum and average force, area under the curve, and mixed linear modeling. A total of 207 grip profiles from 21 students were collected; 12 completed all sessions. No significant differences were observed in maximum or average peak force or area under the curve. However, regression analysis revealed a statistically significant effect in morning sessions only, where exam-day fatigue occurred more rapidly (p = 0.0013, n = 21). Exam-related stress was associated with accelerated muscle fatigue during morning exams but not in the afternoon. These findings suggest that afternoon testing may mitigate stress-related physiological effects and better preserve performance capacity. The results underscore the potential impact of stress and circadian timing on exam performance and may inform scheduling strategies and wellness interventions in medical education.