4755 - Feasibility and Preliminary Effectiveness of a Sleep Regularity and Circadian Alignment Intervention in Female Athletes: A Pilot Study

Session: D08S0023 - Interventions in Health Psychology 3
AUTHORS:
Walsh Elie (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia) , Leota Josh (Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital ~ Boston, MA 02115 ~ USA) , Mascaro Luis (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia) , Crick Benjamin J. (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia) , Liddle Sarah (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia) , Drummond Sean P A (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia) , Facer-Childs Elise R. (School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk ~ Clayton, Victoria, 3800 ~ Australia)
Abstract text:
Introduction:
Sleep, circadian rhythms, and mental health are tightly coupled, yet most sleep programs still prioritise generic sleep hygiene over targeting the internal circadian clock. We developed a novel, co-designed intervention that integrates Cognitive Behavioural Therapy for Insomnia with circadian science to promote regular, phase-aligned sleep-wake schedules as a pathway to better mental health.
Purpose:
To examine the feasibility, acceptability, and preliminary effectiveness of this sleep regularity and circadian alignment intervention in female athletes.
Method:
Thirty-one female sub-elite athletes completed a single-arm 3-week baseline and 4-week intervention pilot. Athletes wore a wrist-worn biometric device to monitor objective rest-activity patterns and completed daily journals assessing light exposure, mood, and recovery. Sleep, dim light melatonin onset (DLMO), and mental health outcomes were assessed pre- and post-intervention.
Results:
Recruitment (96.9%) and retention (100%) were excellent, with no adverse events. Coaching attendance was high (93.6%). Despite improvements in alignment to prescribed targets, objective adherence to the combined sleep-onset and wake-time coaching window was achieved on only 22.3% of nights during the intervention; when outside targets, deviations could be substantial (up to ~5 hours). Sleep regularity indices did not change at the group level. Sleep duration (+13 min) and efficiency (+4%) improved, with reductions in wake after sleep onset (-19 min), sleep disturbances, and sleep debt (all p ≤ .01). Phase angle reduced during the intervention (p < .001) indicating better circadian alignment and insomnia severity and pre-sleep arousal decreased (p ≤ .03). Mental health improvements were observed among athletes who maintained more regular sleep (p ≤ .05).
Conclusions:
The intervention was feasible, acceptable, and deliverable within a real-world preseason training environment. Sleep and circadian alignment improved, and mental health benefits were most evident among athletes who maintained more regular sleep. These findings support a shift toward precision circadian optimisation rather than generic sleep hygiene.