When owls struggle at work: chronotype, burnout, and work ability in shift and non-shift employees

Evening chronotype has been linked to poorer occupational functioning, yet the mechanisms through which circadian preference relates to work ability remain insufficiently understood. This study examined whether job burnout functions as a psychological pathway connecting chronotype to work ability and whether this mechanism operates similarly in day workers and employees working shifts including night work. A cross-sectional Computer-Assisted Web Interviewing (CAWI) survey was conducted among 1,293 employed adults in Poland. Confirmatory factor analyses (CFA) and multi-group CFAs confirmed the factorial validity and full measurement invariance of all measures across both groups. Mediation models controlling for age and gender revealed a consistent mediation pattern in day and shift workers, with no significant between-group differences in path coefficients or indirect effects. Specifically, morningness was associated with lower burnout and higher work ability, burnout was strongly and negatively related to work ability, and the indirect effect of chronotype on work ability via burnout was significant, indicating partial mediation alongside a remaining direct effect. These findings demonstrate a general psychological mechanism linking chronotype to work ability that operates independently of formal shift work. The structural equivalence across groups suggests that chronotype-related vulnerability is not limited to shift work but may emerge under any rigid work schedule misaligned with individual circadian preferences. Chronotype-sensitive work arrangements and burnout-prevention strategies may therefore support sustainable work ability, particularly among employees with evening chronotypes.