Sleep is important for youth athletes, supporting sport-related recovery and performance, as well as growth and development. Sleep may be influenced by training factors
therefore, this study aimed to characterise youth athletes' sleep, and examine associations between training load, schedule and frequency, and sleep. Twenty-six youth basketballers (age: 14.22 ± 0.74 years, 13 male, 13 female) from a high-performance sporting school were monitored for a period of 8 weeks. Sleep measures (via actigraphy and sleep diaries) were collected alongside training diaries (recording time, duration and perceived exertion). Youth athletes who finished training after 20:30 hours had significantly less total sleep time than when training finished before 20:30 hours. Higher daily total training duration was associated with decreased total sleep time. There is a potential contradiction with findings related to the number of sessions per day, as participants who completed two training sessions in a day had more sleep than those who completed one session per day
but this was not observed for athletes with three sessions per day. Participants had large intra-individual variations (mean intra-individual standard deviation) in bedtime (1.06 hr) and sleep time (0.84 hr). In conclusion: (1) late night training sessions appear to reduce total sleep time and should be avoided in youth athletes
(2) total daily training duration had a greater negative effect on sleep than session frequency
and (3) participants' large intra-individual variation in bedtime may reduce sleep quality and efficiency.