RESUMEN
BACKGROUND: Although breaks are essential to restoring cognitive and psychological conditions for learning, short breaks within school lessons are not established and the specificity of effects has not often been investigated. Therefore, the effects of a physical activity (Study 1) and a mindfulness intervention (Study 2) were investigated. PROCEDURE: By an intervention-control group design, the effects of daily 10-min physical activity (Study 1: N = 162, 4th grade) and mindfulness breaks (Study 2: N = 79, 5th grade) were implemented within regular school lessons over a 2-week time period to research the impact on attention, reading comprehension, and self-esteem. RESULTS: In the physical activity intervention children's attention improved (attention-processing speed: p < .004, ηp2 = .05, attention-performance: p < .025, ηp2 = .03), and in the mindfulness intervention reading comprehension improved (p < .012, ηp2 = .08) compared to the controls. Results further indicated that self-esteem moderated the relationship between groups and attention improvement in study 1. CONCLUSION: Classroom-based short physical and mindfulness breaks could support attention and reading comprehension, which are known to support overall academic success.