Introduction: Sleep is a crucial factor in recovery and must be integrated into athletes' training plans for optimal performance and wellbeing. Although athletes are advised to sleep for a minimum of 8 h, many experience shorter sleep durations or exhibit poor sleep efficiency. Sleep tracking observations in athletes suggest that quality is 556 of 633 ABSTRACTS 13652869, 2024, S1, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jsr.14291 by Cochrane France, Wiley Online Library on [24/09/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License altered, yet this emerging field of research requires comprehensive assessments, including objective and subjective sleep outputs. To improve sleep quality, sleep interventions have been tested with various modalities, including sleep hygiene education and strategies. Thus, across match weeks, this ecological study aimed to identify good and poor sleepers within a male rugby team, using both objective and subjective assessments, and to evaluate the effects of sleep interventions. Method: Forty-three male professional rugby players from national French rugby union were evaluated during two tracking and intervention match weeks using objective and subjective assessments (actimeter and Hooper questionnaire). During the first tracking week, we assessed the wake-sleep cycle of athletes who maintained their daily habits. Then, two sleep experts reported the results from the tracking phase in a group setting context and offered an educational session on sleep hygiene (30 min). Experts further taught them how to practice relaxation strategies, which they could implement as needed during the post-intervention week. Results: Our findings revealed that 65% of players were bad sleepers. Subjective sleep quality improved between the tracking and the intervention weeks (p = 0.002). A significant effect of the sleep interventions was also found on bedtime (p = 0.005), which occurred earlier during the intervention week (23:25 ± 00:38 vs. 23:43 ± 00:44 tracking). A trend towards significant increases in objective (actimetric) sleep quantity was also observed (421.3 min tracking vs. 433.4 min intervention; p = 0.07). Conclusion: The first main finding revealed that a majority of rugby players did not sleep sufficiently, which extends previously reported results from different sports. The second main finding demonstrated that sleep interventions improved sleep quality and quantity. This study offers an accessible method for evaluating sleep in team sports athletes, while providing feedback to optimize or enhance sleep quality and quantity. Conflict of Interest: No.