Sleep Quality and Sleep Timing in Adolescent Gymnasts: A Cross-Sectional Study

Given the limited pediatric-specific evidence in this area, we aimed to examine the association between federated-level gymnastics participation and sleep quality and sleep timing in adolescents. The global Pittsburgh Sleep Quality Index (PSQI) score was defined as the primary outcome, sleep-timing measures as secondary outcomes, and individual PSQI component analyses as exploratory.

This observational, cross-sectional comparative study included adolescents aged 12 to 16 years participating in federated gymnastics and controls who did not participate in federated sports. Demographic variables included age, sex, and parental educational level, while training-related variables included weekly training duration, number of training sessions, and training schedule. Sleep quality was assessed using the PSQI, and bedtime, wake-up time, sleep duration, and sleep latency were derived from the corresponding PSQI items. Multiple linear regression models included age, sex, maternal educational level, and paternal educational level as covariates.

The study included 60 gymnasts and 37 controls, with baseline differences in age, sex distribution, and parental educational level between groups. Gymnasts trained a median of 12.0 hours/week (Q1-Q3: 8.25 to 20.0) over five sessions/week (Q1-Q3: 4 to 6), with a median training-session end time of 20:30 (range: 18:00 to 22:00). In adjusted analyses, gymnast status was associated with later bedtime (B=0.392 hours, 95% CI 0.043 to 0.740, p=0.028), whereas no statistically significant association was observed between study group and global PSQI score (B=0.311, 95% CI -0.720 to 1.343, p=0.550). Increasing age was associated with later bedtime (B=0.231 hours, p=0.004) and shorter sleep duration (B=-0.398 hours, 95% CI -0.560 to -0.236, p<0.001). Among gymnasts, training-session end time was not associated with global PSQI score (B=0.141, 95% CI -0.344 to 0.625, p=0.563; R²=0.006). Overall, 19/97 participants (19.6%) met the conventional PSQI >5 threshold for poor sleep quality, although an optimal adolescent-specific clinical cutoff has not been definitively established.

No statistically significant difference in adjusted global PSQI score was detected between federated adolescent gymnasts and controls. Gymnast status was associated with later bedtime. Approximately one in five participants met the conventional PSQI >5 threshold for poor sleep quality. Given the cross-sectional design, these findings should be interpreted as associations, and larger longitudinal studies incorporating objective sleep measures are warranted.