What determines skill at ball sports?
An investigation by Jobu University and collaborators

The group led by Professor Hirofumi Sekiguchi and Associate Professor Shigeo Takeuchi of the Department of Sports and Health Management, School of Business Information, Jobu University--in collaboration with the Showa Women's University, Josai University, Kochi University of Technology, Shizuoka University, and the University of Tokyo--investigated which experiences were associated with better results in one-handed, two-ball juggling performed for the first time. The study included university students with a wide range of sports history and found that those who have more years of experience in ball sports have better success. Knowing in advance the experience required for rapid skill improvement may help reduce future exercise aversion in young children. The results were published in the June 28 issue of Scientific Reports, an international journal.

Those who improve quickly even in their first sporting activity are hypothesized to have "talent" and "good reflexes," although scientific explanations have not been established. Previous studies have reported that the brain responds better when viewing familiar movements than when viewing unfamiliar movements and that diverse experiences are considered beneficial for the acquisition of new motor skills. The current study focused on sports history (i.e., types, years of experience) and investigated whether previous diverse sports experiences were related to improvement in juggling skills. Additionally, the characteristics of the nervous system related to development of these skills were examined using transcranial magnetic stimulation (TMS).

Twenty-eight healthy college students (males, 22; females, 6; mean age, 19.8 years) participated in the experiment. Initially, electromyography was performed on the right biceps brachii, and input-output characteristics of the corticospinal tract were recorded by TMS. Once again, the participants were challenged to perform two-ball juggling that none of them had previously performed. Specifically, each participant performed 25 sessions (one session with 10 challenges) of juggling using their right hand.

Success was evaluated according to the number of times a ball was dropped or the movement stopped during the challenge. Participants were first asked to try one session without any hints. At that time, the average number of successful catches was 11.8 ± 4, and only one catch on average was made per challenge. Twenty-five sessions were subsequently held and the participants were shown a how-to tutorial video. Each participant was then subjected to an in-depth interview regarding their sports experience to explore its relationship with juggling success.

Of the 28 participants, five had no history of playing ball sports and two had no history of playing non-ball sports. All other participants had some degree of experience of playing ball sports, with varying years of experience. The results showed that there was a positive correlation between the years of experience in existing ball-based sports and the number of catch successes. In contrast, there was no correlation between the number of sports activities and the number of catch successes in ball and non-ball sports played by the participants.

There was a stronger positive correlation between the years of experience in ball sports and the number of successful catches than that between the cumulative years of experience of all ball sports of an individual and the number of successful catches. It was shown that a skill in a single-ball sport may be important for the acquisition of new ball sport skills. Additionally, since the ball size for the game and whether the ball is operated by hand or by foot were not included in the analysis, it may be important to consider the "type of ball" in skill acquisition. Furthermore, from the input-output characteristics of TMS, the longer the experience of playing ball sports, the more precise muscle output is possible; conversely, the longer the experience of playing non-ball sports, the larger the muscle output with a few motor commands.

Numerous studies have shown that despite genetic influences, repeated exercises alter the nervous system. It is likely that several years of experience lead to changes in responses during sports activities. Professor Sekiguchi stated, "By conducting future investigations involving young people and adults who have a lot of sports experience, and, later, children who have little experience, the required experience for the development of specific motor skills will be clarified. If we characterize those who rapidly acquire skills and consider the necessary training and exercise experience, we will be able to recommend how to organize an exercise guide and a physical education curriculum for young children. We also expect that such studies will lead to the development of more effective methods for the rehabilitation of persons with disabilities and the older population."