Sleep plays an important role in mental and physical recovery for athletes training hard on a daily basis [1]. Multiple recent systematic reviews have suggested that athletes’ insufficient quality and quantity of sleep leads to potential decline in physical performance (e.g., sudden power and 5 endurance), decline in cognitive performance (e.g., attention and memory), and increase the risk of illness or injury [2,3]. It has also been reported that 30.6% of top athletes have sleep disorders [4]. Therefore, prevention and improvement of sleep disorders are essential for improving competitive abilities and maintaining athletic conditioning. Lifestyle habits are serious risk factors for sleep disorders. Research on adolescents and adults has reported that smoking [5], drinking [6], regularity of mealtimes [7], skipping breakfast [8], late night part-time jobs [9], and use of electronics such as smartphones/cellphones after lights out [10] are all related to sleep disorders. However, the relation between these lifestyle habits and sleep disorders among athletes has not yet been studied. In general, exercise is considered to contribute to improved sleep quality and longer sleep duration [11]; however, over-exercising can possibly increase arousal levels and inhibit sleep [12]. Thus far, research has reported that an increase in practices causes sleep disorders among athletes [13], and those with early morning practices have shorter sleep duration [14]. Yet these studies are insufficient. Furthermore, empirical studies on sleep and psychological stressors have been conducted mainly in the work field, reporting that high occupational stressors related to poor sleep quality [15], long sleep latency [15], and insomnia [16]. Therefore, presumably, competition stress becomes a risk factor in sleep disorders for athletes. However it has only been reported that feeling stagnated with respect to competition results is related to sleep disturbances [17], and such studies are insufficient. It is also well known that the impact of psychological factors such as depressive symptoms and psychological distress negatively affect sleep [18]. Previous studies found that depressive symptoms were strong risk factors of sleep disorders among university students [19,20]. Although a few study reported that depressive symptoms related sleep disorders among adolescent athletes [21], there is no study investigating these relationships considering the effect of lifestyle habits and competition activities.