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Introduction Pilot sleepiness in flight continues to be an issue in aviation due to irregular and extended working hours. In some regions of the world, pilots are allowed to use an in-flight countermeasure called controlled rest, which involves taking a short nap on the flight deck. The use of this countermeasure in practice is understudied. We aimed to investigate whether subjective sleepiness ratings taken pre-flight are predictive of controlled rest use. Methods Data from 94 long (> 6 hours flight duration), non-augmented (two flight crewmembers) flights were analyzed (n = 30 pilots). Mixed-effects logistic regression was used to assess the likelihood of controlled rest based on a Karolinska Sleepiness Scale rating (KSS) taken at pre-flight. Results Controlled rest was taken on 62.77% (n = 59) of the analyzed flights. Pilots with higher KSS ratings (i.e., subjectively sleepier) pre-flight were more likely to take controlled rest during the subsequent flight (b ± SE: 1.03 ± 0.33; OR = 2.81, 95% CI [1.47, 5.37]; p = .002; R2 (Marginal): .28, R2 (Conditional): .51). That is, for every one-unit increase in KSS ratings, there was a near three-fold increase in the odds of taking controlled rest in flight. Conclusion Our results suggest that subjective sleepiness prior to a flight may be predictive of the decision to take controlled rest later in the flight. Further research is needed to understand the influence of other scheduling factors and individual differences. Support (if any) NASA Airspace Operations and Safety Program, System-Wide Safety Project.

Maritime piloting operations involve on-call work schedules that may lead to sleep loss and circadian misalignment. Our study documented pilot work scheduling practices (n = 61) over a one-year period. Most pilots worked a week-on/week-off schedule. Work periods averaged 7.6 hours in duration and pilots worked up to four ship assignments during a given work period. Work weeks averaged a total of 35.0 hours with pilots working on average three consecutive days. Night work was common (19.0 hours/week) with 02:00 h the most common starting hour for a work period. On-call work periods occurred at irregular times with a high degree of start time variability between consecutive work periods. While typical individual and weekly work total hours were not high, there were instances with long work periods, minimal rest opportunities, and extended total weekly work hours. Fatigue-model predictions based on work schedules were similar to objective outcomes collected among other groups of maritime pilots and may prove useful in identifying potential fatigue risks within on-call work schedules. Future studies should be conducted using objective measures to provide further insight on how on-call maritime operations influence sleep timing, alertness, and performance.

Introduction Sleep inertia symptoms typically occur after waking from nocturnal sleep. Under laboratory settings, light exposure upon waking has been shown to improve alertness, mood, and vigilant attention. We investigated whether a field-deployable light-emitting device would help to improve alertness and working memory in a real-world setting. Methods Thirty-five participants (18 female; 26.4 ± 6.0 y) completed an at-home, within-subject, randomized crossover study. Participants wore actiwatches during their normal sleep-wake schedule for five nights ahead of the adaptation and experimental nights. On the experimental night, participants performed baseline testing before their self-selected bedtime. Forty-five minutes after bedtime, participants received a phone call and were instructed to perform test bouts while wearing light-emitting glasses with the light either on (light condition) or off (control). A 3-minute descending subtraction task (DST) and the Karolinska Sleepiness Scale (KSS) were performed at +7, +17, +27, and +37 minutes after the call. Participants were then instructed to go back to sleep and were called 45 minutes after lights out to repeat the test bouts in the opposite condition. A series of mixed-effects models were performed with fixed effects of condition, test bout, and their interaction, and a random effect of participant. Condition order, sex, and baseline were included as covariates. Results There was a significant effect of test bout for DST total responses (χ2 [3] = 17.42; p < .001) and total correct (χ2 [3] = 21.29; p < .001) with improved performance at +27 and +37 minutes compared to +7 minutes. Sex was a significant predictor for KSS (F1,30 = 10.26; p = .003), with females (8.20 ± 0.23) rating higher sleepiness than males (7.10 ± 0.25). There were no other significant effects for DST or KSS outcomes (p > .05). Conclusion These results suggest that the intervention was not able to improve working memory or alertness under naturalistic at-home settings. Further analysis is needed to determine whether these results are applicable to other cognitive performance domains. Support (If Any) Funded by the Naval Postgraduate School, via the Naval Medical Research Center's Naval Advanced Medical Development Department (MIPR N3239820WXHN007), with support from the NASA Airspace Operations and Safety Program, System-Wide Safety.

Introduction Daylight Savings Time (DST) has been a well-studied occurrence in United States society. Past literature has documented numerous detriments related to cardiovascular and mental health, as well as heightened accident risk (e.g., traffic, construction, healthcare) due to this time shift. Given the scant research in professional sports though, the current study examines the impact of DST among National Basketball Association (NBA) teams. Methods Following the 2011-12 lockout-shortened season, data for all games played during the 2012-13 to 2019-20 NBA seasons were collected from the publicly-available sports database, Basketball-Reference. Data from the 2020-21 season were excluded due to the impact of the COVID-19 pandemic. During this period, data from 8,843 games were obtained, with 65 of these games being played the same day as DST. We investigated the influence of DST on points scored, points allowed, and game outcomes for both the home and visiting teams using mixed-effects regressions controlling for season and when applicable, winning percentage. Specifically, we compared team performance for games immediately following DST with season averages. Results For both home and visiting teams, our regression models revealed no meaningful variations in performance between games played following DST and season averages. There were no statistically significant differences across points scored (pHome = .98, R2Marginal = .21, R2Conditional = .29; pVisiting = .36, R2Marginal = .32, R2Conditional = .45), points allowed (pHome = .84, R2Marginal = .34, R2Conditional = .42; pVisiting = .44, R2Marginal = .22, R2Conditional = .33), and game outcomes (pHome = .77, R2Marginal = .11, R2Conditional = .11; pVisiting = .71, R2Marginal = .10, R2Conditional = .18). Conclusion The present analysis offers preliminary evidence that DST may not produce any observable effects on the selected indicators of team performance. However, our results could be explained by organizational and athlete sensitivity toward potential compromised performance during games played following DST. Furthermore, our study did not consider other variables that could impact teams (e.g., actual sleep schedules and travel), and was limited by a relatively small sample size of games played on DST. We suggest that future studies examine additional metrics implicated in team performance, such as shooting percentages, rebound rates, turnovers, among others. Support (If Any) None

Introduction Previous investigations in professional basketball, football, and other sports have shown meaningful effects of factors like rest and length of a team’s road trip on overall performance, with detriments being attributed to travel. However, prior research in the context of college basketball has been relatively scant. Thus, the current study extends the literature by performing a case study on the impact of such travel factors on a women’s college basketball team. Methods Data from a total of 110 road games played over the last 10 seasons from 2010 to 2020 by a National Association of Intercollegiate Athletics (NAIA) women’s college basketball team were collected from the college’s athletics site. We examined the influence of consecutive games played away, days in between games, back-to-back games, and miles traveled by the team on game outcomes and team performance. Specifically, we inspected box-score statistics, such as points scored, points allowed, shooting percentages (i.e., field-goal, free-throw, and three-point), rebounds, blocks, steals, assists, personal fouls, and turnovers. We performed a series of generalized regressions controlling for the team and opponent winning percentages entering each game, along with the opponent’s home time zone. Although neutral site games were excluded from our analyses, such events were still considered in determining the number of consecutive games played away from home. Results Our analyses revealed that the team scored significantly more points (p = .03), and won more games (p = .04) when traveling fewer miles away from their home city. We also found that fewer consecutive games played away were related to significantly more blocks of opponent shots (p = .02). Ultimately, the team shot significantly higher from the field when there were more days in between games (p = .03). Conclusion Findings from the present study reveal that certain aspects of team performance on the road appear to be influenced by miles traveled from the college’s home city, consecutive games played away, and days in between games. Results could be applied beyond the current context, whereby college basketball teams could utilize such findings to mitigate the impact of travel on athletes. Support (if any) None

Introduction Previous research in professional basketball and baseball has shown that traveling up to three hours westward can hamper performance due to circadian disadvantages. However, findings in the context of collegiate football are conflicting, as some prior studies have reported negative effects on scoring during either eastward or westward travel. The current study extends the literature by investigating the impact of travel on both offensive and defensive team performance within National Collegiate Athletic Association (NCAA) Division I college football. Methods Following the NCAA’s introduction of the College Football Playoff in 2014, data from 1,909 away games from 64 “Power Five” conference teams played during the 2014 to 2019 regular seasons were collected from the publicly available sports database, Sports-Reference. For the purposes of our analyses, we excluded all games played at neutral sites. We examined the effects of the direction of travel away from the college’s home city and time of game day on visiting team performance, specifically game outcomes, points scored, points allowed, completion percentages, penalties, fumbles, interceptions, and total turnovers forced and committed, controlling for both visiting and home team conference, day of game, and team rankings. Results Teams playing in the afternoon allowed significantly more points (OR = 1.05, p < .001) and forced more opponent turnovers than those playing in the evening (OR = 1.14, p = .05). Teams traveling eastward threw significantly more interceptions than those traveling in the same time zone (OR = 1.48, p = .004). A significant interaction between direction of travel and time of day was detected for points allowed (χ2 = 12.30, p = .02), and a marginal interaction was present for points scored (χ2 = 8.42, p = .08). Several other marginal differences were also identified for points scored, interceptions, and team turnovers (OR > 1.03, p < .10). Conclusion Findings from our study offer evidence for the influence of circadian factors on team points allowed, interceptions, and opponent turnovers forced. Specifically, travel in varying directions and the time of day when a game is played can impact team performance during away games within college football. Support (if any) None

Introduction Prior research on travel in the National Basketball Association’s (NBA) regular season has shown that teams journeying west relative to their home base face circadian disadvantages for evening games, while those traveling east have advantages. The current study extends previous research by examining these effects within the NBA playoffs. We hypothesized that teams would have a greater circadian advantage during eastward compared to westward travel. Methods In 2013, the NBA implemented a 7-game series playoff structure, in which teams play an alternating home/away 2-2-1-1-1 format. Data for all 499 postseason games played during the 2013–14 to 2018–2019 seasons were collected from Basketball-Reference and FiveThirtyEight. We investigated the impact of direction of travel based on home base city (same time zone, westward, eastward) and time zones traveled on game outcomes, Elo rating differences (i.e., a team quality metric based on wins and losses), win probability, and team scoring. Results Teams had lower win probabilities following 3-hour westward than same time zone and all eastward travel, while 3-hour eastward travel related to higher probabilities of winning compared to same time and all westward travel (p < .001, d > .95). Teams travelling westward with 2-hour time changes lost significantly more games than those experiencing 1-hour westward (p = .04, OR = 2.45), 1-hour eastward (p = .05, OR = 2.34), and 3-hour eastward changes (p = .02, OR = 4.68). Scoring was significantly higher following eastward travel compared to both westward (p = .001, d = 0.60) and same time zone travel (p = .003, d = 0.44). There were no differences in team quality based on direction of travel or number of time zones traveled, and game outcomes based on overall direction of travel (p > .05). Conclusion Direction and magnitude of travel were related to win probability, team scoring, and game outcomes, whereby teams travelling eastward and within the same time zone gained an advantage over those travelling westward. Adjustment to travel and time changes appear to influence in-game performances and outcomes in the NBA playoffs. Support None