In high-risk industries, employees' ability to work safely each day is crucial for occupational health and organizational safety. As such, it is essential for employees to be physiologically prepared at the start of the workday to adapt to safety demands of risky working environments. Sleep is a vital process for physical recovery. Good sleep can lead to a more typical cortisol awakening response (CAR) in the morning, reflecting physiological preparedness for the upcoming workday. By raising alertness and enhancing executive function, a robust CAR enables the employee to regulate themselves better, such as inhibiting unsafe impulses and being vigilant to monitor potential safety risks, resulting in more safety behaviors. Therefore, we applied a diary method to investigate the impact of prior-night insomnia on CAR and next-day safety behaviors. 104 frontline employees provided morning saliva samples and completed daily surveys across five workdays. Results showed that insomnia significantly weakened CAR the following morning, which, in turn, reduced safety compliance and participation behaviors, with CAR mediating the relationship between insomnia and safety behavior. These findings highlight hormonal factors as key antecedents of safety behaviors and provide empirical evidence to guide organizations in developing pre-shift fitness practices to enhance employee safety and health.
