title: The effect of time-of-day on static and dynamic balance in recreational athletes.
abstract: The purpose of this study was to investigate the effect of time-of-day (morning vs. afternoon) on static and dynamic balance in recreational athletes. A total of 34 recreational athletes completed the single-leg stance test with or without eyes open, lower quarter Y-balance test, upper quarter Y-balance test, and single-leg landing balance test in a random order in the morning (7:00-10:00 am) and afternoon (3:00-6:00 pm) for two consecutive days. Compared with the morning, participants demonstrated decreased centre of pressure (COP) sway areas (p = 0.002; Cohen's d (d) = 0.28) and sway speeds (p = 0.002; d = 0.17) during the eyes-open single-leg stance test, increased stance time (p = 0.031; d = 0.16) and decreased COP sway areas (p = 0.029; d = 0.22) during the eyes-closed single-leg stance test, and increased reaching distances (p = 0.024; d = 0.10) during the upper quarter Y-balance test in the afternoon. The between-day effect (day 1 vs. day 2) was observed for several parameters. Time-of-day had a minimal effect on dynamic balance and a noticeable effect on static balance. Time-of-day may be considered as a factor in designing balance training programmes and intervention studies for recreational athletes.
authors.affiliation: a Division of Kinesiology and Health , University of Wyoming , Laramie , WY , USA.
authors.forename: Erika M
authors.initials: EM
authors.lastname: Heinbaugh
authors.affiliation: a Division of Kinesiology and Health , University of Wyoming , Laramie , WY , USA.
authors.forename: Derek T
authors.initials: DT
authors.lastname: Smith
authors.affiliation: a Division of Kinesiology and Health , University of Wyoming , Laramie , WY , USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: b Department of Theatre and Dance , University of Wyoming , Laramie , WY , USA.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Wilson
authors.affiliation: a Division of Kinesiology and Health , University of Wyoming , Laramie , WY , USA.
authors.forename: Boyi
authors.initials: B
authors.lastname: Dai
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002940:Circadian Rhythm; D005080:Exercise Test; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D004856:Postural Balance; D013177:Sports / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Circadian rhythms; centre of pressure; injury risks; performance; postural control