ResultsCharacteristics of subjects divided into good and poor sleeper groups are presented in Table 1. There were no significant differences in age, height, body weight, andbadminton career between good and poor sleeper groups. Sleep variables as assessed by actigraphy and parental sleep questionnaires are presented in Table 2. There were no significant differences in sleep duration (good sleepers, 520 ± 7 min; and poor sleepers, 538 ± 10 min) and total CSHQ scores (good sleepers, 45.8 ± 2.3; and poor sleep- ers, 45.0 ± 1.9) as reported by parental sleep questionnaires between the two groups. However, actigraphy data indicated that on an average, the good sleeper group had a shorter sleep latency (p < 0.05, effect size = 1.40), longer wake after sleep onset (p < 0.001, effect size = 2.83), longer total sleep time (p < 0.005, effect size = 2.24), and higher sleep effi- ciency (p < 0.001, effect size = 2.85) than the poor sleeper group. The subscale CSHQ scores are listed in Table 3. Sleep duration score was significantly higher (p < 0.05) and