Purpose. The aim of the study was to examine the role of job-related positive and negative emotions between acute fatigue at work and engagement. We tested two components of engagement: vigor (energetic aspect) and dedication (motivational aspect). We hypothesized that negative emotions mediate in energy depletion process and positive emotions mediate in broadening of energetic and motivational resources.

Design/Methodology. Fatigue was measured by an index in accordance with the Japan Society for Occupational Health. The Utrecht Work Engagement Scale – short version (UWES) was used to evaluate vigor and dedication (Schaufeli, Bakker, & Salanova, 2006). Job-related affective well-being (JAWS) was used to assess positive and negative emotions (Van Katwyk et al., 2000). The study group consisted of 174 police officers (the average tenure of 10 years, range 1–23).

Results. Baron and Kenny approach and the Sobel test supported our hypotheses. Fatigue was more negative related to vigor than dedication. We observed that positive and negative emotions fully mediated between fatigue and vigor (large effect size f2 = .36). Additionally, positive emotions fully mediated between fatigue and dedication (medium effect size f2 = .16). We confirmed these results by the Sobel test.

Limitations. The correlational design was applied.

Research/Practical Implications. Our results indicate that in police officers positive emotions may lead to broadening of energetic and motivational resources.