Intervention study using a leaflet entitled ‘three benefits of “go to bed early! get up early! and intake nutritionally rich breakfast!” a message for athletes’ to improve the soccer performance of university soccer team

A new educational material was created for athletes. It was focused on three benefits of a morning-typed lifestyle and actual strategies for promoting this lifestyle. The material is a leaflet entitled, “Three benefits from going to bed early, getting up early and taking nutritionallyrich breakfast. Message to athletes!” This study tried to evaluate the educational efficacy of a month-long intervention using this leaflet on Japanese university soccer team members. Eighty-four members of university soccer team were asked to participate in a month-long intervention from mid-November, 2011. Just before and 3 months after the intervention period, an anonymous integrated questionnaire was administered to participants. Another questionnaire including questions on the change in soccer performance was administered at the middle and the end of intervention month. Responses were received from more than 95 % of the soccer team members. The participants just after the intervention tend to show higher quality of sleep (p = 0.020) and lower frequency of irritation (p = 0.006) than those before the intervention. Analysis on the sleep diaryincluding questions on the implementation of 8 issues as contents of the leaflet showed that the sleep latency and sleep quality at nights when participants used computer game, was longer (p < 0.001) and worse (p < 0.001), respectively than those at nights when they did not. The positive and significant correlation was shown between mental health (GHQ) just after the intervention and the improvement of soccer performance (Better mental health correlates with performance improvement) (p < 0.001). In the best performance team (A+), 70 % of the team changed to more morning-typed and significant and positive correlation between the diurnal type scores (high scores mean morning-typed) just after the intervention and degree of performance improvement( morning-type correlates with performance improvement) (p < 0.001). The intervention using the leaflet could be effective for improvement of soccer performance via changing to morning-typed life.