P077 Associations of sex, sleep, and circadian rhythms with performance in elite Australian Rules footballers

INTRODUCTION: Poor sleep and circadian misalignment are associated with poorer performance. In elite Australian Rules football (ARF), both sex and professionalism could alter or exacerbate these associations. This study provides preliminary insights on how the relationships of sleep and circadian alignment with cognitive performance differ between male full-professional and female semi-professional elite ARF athletes. METHODS: Participants were 72 elite ARF athletes (42% female; M-age = 24.1±4.4 years). During pre-season, participants completed two weeks of sleep/wake monitoring via actigraphy, and a circadian phase assessment (dim light melatonin onset; DLMO) after one week. Cognitive performance testing (psychomotor vigilance task, PVT; and the balloon analogue risk task; BART) was conducted five times throughout this period. RESULTS: Preliminary findings suggest average total sleep time and sleep efficiency, sleep regularity, DLMO, and phase angle (interval between average sleep onset and DLMO) did not predict reaction time on the PVT, nor did sex moderate these relationships. After controlling for sex, longer sleepers demonstrated greater risk taking on the BART. Only among male athletes did larger angles predict greater risk taking. DISCUSSION: Elite ARF athletes, regardless of sex, sleep, or circadian alignment, have similar reaction times. Risk taking is greater among longer sleepers and in male athletes experiencing relatively delayed circadian phases. Where risk-taking has negative implications (e.g., injury and sporting errors), these findings identify at-risk groups. Few sex-specific findings may suggest that the semi-professional status of female ARF (and associated lifestyle factors such as scheduling and income) is not altering elite performance in controlled settings.