Grounded in self-regulatory resources and conservation of resources theories, the current research examines poor self-regulatory capacity as a precursor to microbreaks and their possible outcomes at work. Full-time employees completed multiple online surveys for 10 (n₁ = 779 daily observations) and 5 workdays (n₂ = 1,024 daily observations). In Study 1, multilevel path analysis results showed that on days when employees had poorer recovery at home (i.e., poor sleep quality), they experienced higher fatigue in the next morning (low self-regulatory capacity) and thus took microbreaks more frequently at work. In turn, their engagement in microbreaks was related to higher work engagement during the day and lower end-of-work fatigue. Furthermore, perceived health climate was found to moderate the path from morning fatigue to microbreaks. In Study 2, we replicated and confirmed the serial mediation paths found in Study 1 (poor sleep quality → morning fatigue → microbreaks → work engagement and end-of-work fatigue). Building on Study 1, Study 2 also identified microbreak autonomy as a mechanism by which perceived health climate moderates the path between morning fatigue and microbreaks (i.e., mediated moderation effect). Exploratory analyses discovered intriguing patterns of socialization microbreaks versus other microbreaks, providing further implications for the theoretical perspective. Overall, the findings support the theoretical resource perspective of microbreaks as an effective energy management strategy while at work. (PsycInfo Database Record (c) 2022 APA, all rights reserved).