Over-commitment positively predicts hair cortisol concentrations only in nurses with high need for recovery.

Purpose: In the contemporary workplace, enduring fatigue has become a standard for employees. This investigation assesses whether such working conditions exacerbate the depletion of employees' personal resources. The need for recovery serves as an indicator of the necessity to mitigate post-work fatigue. A high need for recovery signifies that employees must commence a new workday while already fatigued.

Methods: This research recruited two cohorts of nurses, categorized by a high need for recovery and a low need for recovery, to examine the correlation between work effort and hair cortisol concentrations in each group.

Results: Hair cortisol concentrations serve as a biological marker of cumulative cortisol secretion over a specific time frame, reflecting overall personal resource expenditure during this interval. Findings revealed a notable positive correlation between intrinsic work effort (over-commitment) and hair cortisol levels exclusively among nurses with a high need for recovery.

Conclusion: These outcomes imply that active effort amidst fatigue may lead to excessive strain. This insight enriches the classic 'effort-recovery' model by illustrating how an employee' s personal volition can influence the accumulation of fatigue.