Abstract
OBJECTIVES: This study aims to investigate the time-dependent pattern of employees' work stress responses. It seeks to determine whether there is a day-of-the-week effect in employees' physiological reactions to workplace stressors on an intra-week scale. METHODS: Utilizing seven-year (2017-2023) biometric data from financial sector employees in Eastern China, we analyzed the association between daily stock returns and cardiovascular biomarkers. A counterfactual analysis during holiday periods was conducted to isolate work-cycle-specific effects from general biological rhythms. RESULTS: Declines in company stock prices significantly elevated employees' systolic blood pressure and blood lipids from Tuesdays to Thursdays (TTTday), with the effect peaking on Tuesdays, remaining significant on Wednesdays, and failing to reach statistical significance on Thursdays. No significant effects were observed on Mondays or Fridays. Holiday-period analyses confirmed this TTTday vulnerability window as a work-cycle-specific phenomenon. CONCLUSIONS: Employees exhibit rhythmic variations in effort and recovery on the sub-weekly scale, and this leads to varying degrees of physiological responses to workplace stress during the workweek.