Time distribution of training/practice as an optimizing parameter has been studied and analyzed. The results obtained were designed to clarify a debate that has been running for more than a century: many authors support the idea that concentrating practice over a short time is more successful, while others state the opposite. Tangible, unequivocal results that show the best learning methods would allow us to define training programs that are more effective and efficient. In order to reach this goal, the selected subjects were initially given a new motor skill to be learned. Sixty children participated in the study. They ranged in age from seven to ten, 30 boys and 30 girls, all elementary school students in the city of Catania, Italy. Experimental protocol defined the preteen s learning of an ocular-manual skill, which was completely new to him or her. Moreover, half of the children had to learn this skill using their dominant hand, while the other half with their weaker hand. Results showed that, as expected, the use of the dominant arm results in a greater number of successes, regardless of age and gender. Moreover, the probability of success increases with the age of the children, independently of they were using the dominant or the non-dominant arm. The observed improvement is associated to significant changes of some kinematic parameters of the gesture, as duration of performance, time to peak and peak acceleration. Furthermore, a training session of only 5 days was sufficient to achieve significant improvements in the success probability of a simple but not usual gesture, as the launch of a tennis ball to hit a target, but only when the children were using the dominant hand. It is therefore reasonable to conclude that, at this age, motor learning is already concentrated on the dominant side However, the improvement observed after 5 days of training was no longer present to a control performed after one week. It can be, therefore, concluded that, in order to learn a new gesture in a stable manner, training must be continued for a greater period of time.