Recovery literature has focused predominantly on recovery processes outside the workplace during nonwork times. Considering a lack of research on momentary recovery at work, we examined four categories of micro-break activities—relaxation, nutrition-intake, social, and cognitive activities—as possible recovery mechanisms in the workplace. Using effort recovery and conservation of resources theories, we hypothesized that micro-break activities attenuate the common stressor–strain relationship between work demands and negative affect. For 10 consecutive workdays, 86 South Korean office workers (842 data points) reported their specific daily work demands right after their lunch hour (Time 1) and then reported their engagement in micro-break activities during the afternoon and negative affective state at the end of the workday (Time 2). As expected, relaxation and social activities reduced the effects of work demands on end-of-workday negative affect. Nutrition intake of beverages and snacks did not have a significant moderating effect. Post hoc analyses, however, revealed that only caffeinated beverages reduced work demands effects on negative affect. Unexpectedly, cognitive activities aggravated the effects of work demands on negative affect. The findings indicate not only the importance of taking micro-breaks but also which types of break activities are beneficial for recovery. Implications, limitations, and future research directions are discussed. Copyright © 2016 John Wiley & Sons, Ltd.