Research suggests that providing children with activities that involve using their bodies to form the shapes of letters can help them acquire pre-reading skills. Little is known, however, as to the extent to which such embodied learning interventions are superior to more traditional pencil-and-paper activities, which of specific arm or body movements are most effective, and whether this approach compensates or exacerbates the learning gap between high- and low-skilled pre-readers. Using a preregistered randomized-controlled experiment (N = 160 kindergarten students, M = 5.18 years, 54% girls), the present study assessed the educational effects of 6-week-long training sessions with increasing degrees of bodily movement integration (pencil-and-paper training vs. arm training vs. arm-body training) on five measures of letter knowledge and script. Aligning with theories of embodied cognition and cognitive load in instructional designs, results showed that integrating arm movement exercises into handwriting training bore the greatest acquisitions in prereading skills overall and were most beneficial to students with initially low prereading skills (compensatory effect against learning inequalities). Implications are drawn on the need to consolidate and replicate present findings, while highlighting their potential for supporting educational effectiveness and equity in kindergarten.