#THIS ARTICLE IN DUTCH

by Frank Molema | 30 January 2020

Whoever wants to become better at his or her sport, should incorporate slightly different materials in their training. Research shows that hockey players practicing with a ball that is unbalanced, develop better technical skills than hockey players working with a normal ball. "Although athletes do not notice the adjustments to the ball, they are more challenged," says Professor Geert Savelsbergh of VU University Amsterdam.

Together with three other researchers, Geert Savelsbergh studied 129 hockey players aged 8,5 on average, who had been playing hockey for almost two years. The researchers divided the children into two groups: one group trained with the regular white ball, the other played with a modified yellow ball. The hockey players then carried out all kinds of exercises focused on basic techniques.

Significant difference
Before the first training, the children had to take a test, covering a dribble course using a regular ball. They had to do this again after the fourth training, when they were timed with a stopwatch. And lo and behold – the group that had been practicing with the modified ball in the four training sessions, turned out to have made significant improvements compared to the other group. After the second period, when the groups had changed balls, the researchers saw this result repeated. Savelsbergh has an explanation for the effect found. "If you train with a regular ball, it seems to get easier after a while", he explains the results of the research he conducted with two colleagues from VU University Amsterdam and the Dutch national football team’s fitness and recovery coach. "Making the yellow ball unbalanced makes the exercises more challenging."

This study was inspired by the Athletics Skills Model (ASM), which has been developed for talent development. Adaptability and creativity are central to this model. Learning methods are made to train adaptability.  Football already used a modified ball but the researchers came up with the idea to use such balls in other popular sports in the Netherlands.

"We do not practice sports, but skills", Savelsbergh explains the ASM principle. “We can hone those skills by doing different sports. Ultimately we connect those skills through coordination skills. We know from previous studies that coordination is an important factor in sport."

A common mistake is that the execution of a certain movement is the same for everyone. Savelsbergh: “We have known for a long time that this is not at all true. Everyone shows about the same pattern, but there are differences because we are built differently."

Train coordination pattern
The researchers point to the so-called Constraints LED approach. This theory is based on three factors that influence optimal movement. The environment (for example the surface on which you play), the organism (your physique) and the task (for example hitting a hockey ball). Suppose you hit a ball on a sandy field, then your environment changes and you have to adjust. That influences the movement. "We make minor changes to train the coordination pattern", says Savelsbergh. “I think that this also stimulates creativity. The body instinctively discovers solutions.”

The approach from ASM shows similarities to the ideas of Frans Bosch, who believes that not the ideal movement, but the limitation of the body and the way in which the body organizes itself are principles of motion study. Savelsbergh also sees the similarities with Bosch. “But he mainly focuses on strength training, which to us is just one element. However, the starting point is the same: varied learning is best for athletes."

Football will be next
Savelsbergh says that there are plans to also use the modified ball in other sports. “We know that various football clubs use modified balls. We are trying to get basketballers interested, and we are still in a trial phase with handball. In the long term, it is our hope to train with modified balls in these sports as well.”