Hair cortisol and work stress: Importance of workload and stress model (JDCS or ERI).

•Hair cortisol and self-reported stress: literature shows mixed findings.•Many studies do not use stressed samples or distinguish between sources of stress.•This study: self-reported stress related to hair cortisol only in high workload sample.•Effort reward imbalance with high overcommitment was related to higher hair cortisol.•A stress threshold may need to be reached to produce changes in hair cortisol.