Re-evaluating fatigue measurement: A comparative study of subjective and objective fatigue tests

Fatigue poses a significant risk in hazardous industries, with forestry being a particularly under-examined domain. Despite the availability of subjective and objective fatigue tests, inconsistencies in their application, selection rationale, and performance remain largely unaddressed in existing literature. This paper investigates the utility and challenges of subjective and objective fatigue assessments through a review of existing literature and two case studies: one intensive longitudinal study with a single participant and another broader study involving 31 participants. Our results reveal strong internal consistency across subjective tests but variable outcomes for objective tests, raising questions about test sensitivity and context-specific reliability. We argue for clearer guidance on fatigue test selection and propose criteria to inform future research in complex, real-world settings like forestry. • Compared six fatigue tests using two case studies. • Subjective tests were consistent and aligned with participant experiences. • Objective tests showed variable results and weak cross-test agreement. • Proposed practical criteria to guide future fatigue test selection.