Previous research showed that children in classes with reduced curriculum ("ready for school classes") perform systematically poorer in short-term memory, attention control and motor coordination skills than children in regular classes. Based on these results, a training to improve children's planning, sequencing, and executive control of motor actions was developed. It includes body coordination, (bi-) manual coordination, rhythm and balance. The tasks stress flexibility of action, interference control and focused attention. Training sessions proceed from easy to complex, from action accuracy to speed, and from teacher guidance to children's self monitoring. Over the course of 3 weeks, 53 children were trained daily for 20 mins. In pre- and posttests, motor coordination was assessed with the M-ABC; focused attention, short-term memory performance, and self-concept was tested with paper-pencil and computerized tasks. Half of the children were trained between pre- and posttest, the other half received the training after posttest. Results revealed no global training effects; however, children in the training condition caught up during training in specific cognitive and motor tasks, and trained children showed a more optimistic self-concept. Training effects were pronounced for children with balance problems. The findings are discussed in terms of reasons for the weak training effects, and potential improvements of the training.