Game Day Time Lag, Behavioral Patterns, and Perceived Condition in Japanese Professional Baseball Players: A Cross-Sectional Study

Alternating day- and night-game schedules may alter athletes’ daily behavioral patterns without time-zone travel. This study aimed to characterize the game day time lag (GDL) and within-player sleep–wake differences across day- and night-game schedules, as well as compare sleep–wake patterns, breakfast frequency, and perceived condition between schedule exposure groups. This cross-sectional study included 53 Japanese professional baseball players: 16 exposed to day- and night-game schedules (DN group) and 37 exposed only to day games (D group). Sleep–wake timing, meal frequency, and perceived condition were assessed using MCTQ-based items, self-reporting, and eight 100 mm visual analog scales. The GDL was defined as the absolute difference in self-reported midsleep between day- and night-game schedules for each player. The mean GDL in the DN group was 2.2 ± 0.5 h (95% CI: 1.9, 2.4 h). Within the DN group, sleep timing was later for night-game than day-game schedules, whereas sleep duration did not differ. Exploratory comparisons showed later sleep timing, lower breakfast frequency, and lower sleep satisfaction in the DN group than in the D group. The schedule exposure completely overlapped with the team status, limiting interpretation of these differences. These findings suggest the importance of considering differences in sleep timing related to the competition schedule when providing conditioning support to professional athletes.