Article

Greater circadian disadvantage during evening games for the National Basketball Association (NBA), National Hockey League (NHL) and National Football League (NFL) teams travelling westward

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Abstract

We investigated the effects of a circadian disadvantage (i.e. playing in a different time zone) on the winning percentages in three major sport leagues in North America: the National Basketball Association, the National Hockey League and the National Football League. We reviewed 5 years of regular season games in the National Basketball Association, National Hockey League and National Football League, and noted the winning percentage of the visiting team depending on the direction of travel (west, east, and same time zone) and game time (day and evening games). T-tests and analysis of variance were performed to evaluate the effects of the circadian disadvantage, its direction, the number of time zones travelled, and the game time on winning percentages in each major league. The results showed an association between the winning percentages and the number of time zones traveled for the away evening games, with a clear disadvantage for the teams travelling westward. There was a significant difference in the teams' winning percentages depending on the travelling direction in the National Basketball Association (F2,5908 = 16.12, P < 0.0001) and the National Hockey League (F2,5639 = 4.48, P = 0.011), and a trend was found in the National Football League (F2,1279 = 2.86, P = 0.058). The effect of the circadian disadvantage transcends the type of sport and needs to be addressed for greater equity among the western and eastern teams in professional sports. These results also highlight the importance of circadian rhythms in sport performance and athletic competitions.

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... Results discerning which direction of travel is more disadvantageous for sport performance have been particularly inconclusive in the previous literature 4, 6 . Notably however, a 2017 study 129 performance has remained contentious, however a recent study in three separate competitions seems to suggest westward travel to be more deleterious to performance in evening based competitions. Studies looking at large numbers of games, over many seasons, from many teams, have reported negative effects of travel over three or less timezones on team-sport performance, with contrasting findings regarding directional specific effects. ...
... Indeed, previous studies investigating relationships between travel and game performance have used game result as the measure of team performance 127,129 . The current study used game result (win vs. loss) as a measure of team performance. ...
... Score differential did not display a relationship with 'circadian desynchronization' (the difference between the time-zones crossed between teams) when direction of travel was not considered. A recent 5-year analysis of the NBA, NHL, and NFL found that westward travel to be more deleterious to game performance than eastward travel 129 . Hence, relationships between score differential and circadian disadvantage were re-examined, with a greater weighting (1 Sleep duration was found to be significantly low in the group for at least two Conditions on day 7, day 6, and day 5, however sleep duration on these nights did not appear to affect game performance. ...
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Introduction: Very little is known about the effects of jet-lag on sleep and game performance in team sports. The Perth based professional rugby union team, the ‘Western Force’, were the most travelled professional sporting team in the world in 2017, travelling over 68,000km and across 44-time zones in the 2017 season. This provided an opportunity to study (i.) the effects of competition and ultra-long-distance (>3 time-zones crossed) air travel on sleep, and (ii.) the effects of sleep and travel on game performance in a Super Rugby team. Methods: Thirty-seven male elite rugby union players completed a survey including validated sleep questionnaires, and 35 players wore a wrist-worn activity monitor (Readiband) for 106 nights (18 pilot, 88 in-season) to provide objective sleep measures. Measurements obtained in-season were separated into four Conditions, each differing in travel requirements (5, 6, and 13 time-zones crossed). Sleep measures were compared using mixed model analyses to determine effects of competition and travel on sleep. Game performance was measured using an individual player performance (IPP) score, which was shown to relate to team game outcomes (win vs. loss), and score differential (difference in game score between two teams) for team performance. Results: Mean score was 6±3 for Epworth Sleepiness Scale and 5±2 for Pittsburgh Sleep Quality Index, and most players were either intermediate (50%) or morning (43%) chronotype. Sleep duration progressively increased in the nights leading into a game, and was significantly reduced following games, particularly in when an early morning next day flight was required (p<0.01 for all). Sleep quality was reduced when night-time sleep occurred during travel (p<0.01), however total sleep duration was not lost when players napped during flights. Individual differences in sleep in preparation for games did not affect performance (p>0.05 for all days). However, a moderate negative trend (r=-0.46, p=0.09) was found between circadian disadvantage (accounting for direction of travel) and score differential. Conclusion: This study demonstrates the adverse effects of ultra-long-distance air travel on sleep and performance of elite rugby union players. Professional sporting teams should be cognisant of these effects when scheduling travel or training following travel, and should emphasise optimal sleep on the three nights prior to a game.
... One study in experienced swimmers showed that athletes' fastest swim times were preceded by the evening diurnal drop in core body temperature (90minutes prior), and could be a future marker to help identify windows for optimum performance (5). Further studies have demonstrated a diurnal variation in key performance indices such as VȮ 2 max, strength, flexibility, sprint speed, and reaction time in athletes (2,4,7). These studies have opened up the exciting prospect of personalized training regimes, and whether athletes may use core body temperature as a marker to identify and appropriately time training programs to maximize the training adaption from each session. ...
... The deleterious effects of jetlag on both health and athletic performance are well documented (1,7). Jet lag is the resultant circadian misalignment between internal circadian rhythms and individuals sleep-wake cycle following travel across three or more time zones (10). ...
... Jet lag is the resultant circadian misalignment between internal circadian rhythms and individuals sleep-wake cycle following travel across three or more time zones (10). However, it appears that even small time zone shifts (1h to 2h) result in a more subtle, yet significant, circadian desynchronization (7). Whereas team physicians, coaches, and athletes are likely to be aware of the symptoms of jet lag (gastrointestinal disorders, daytime fatigue, and sleep disruption), the impacts of circadian desynchronization following smaller time zone shifts are more discreet and may go under the radar (10). ...
... In this regard, NBA players spend more time above 30,000 ft than athletes competing in all other team sports in the United States of America (USA) [7]. Air travel requirements are a concern for NBA coaches, players, and owners, as research has demonstrated short-haul flights (≤6 h) increase injury risk [2,[9][10][11][12][13] and impede performance [9,[14][15][16][17][18][19][20]. Competing in away games has been reported to significantly increase regular season injury risk in a sample of 1443 NBA players between 2012 and 2015 [9]. ...
... Specifically, 54% of regular season injuries occurred in players playing games away from home, which was significantly greater than the expected injury rate for away games of 50% (p < 0.05) [9]. Furthermore, the direction of air travel should be considered by NBA teams, as traveling westward exacerbates reductions in performance [14,21]. In a sample of 8495 NBA games between 1987 and 1995, west coast teams scored four more points per game (p < 0.05) when traveling to the east coast than east coast teams scored when traveling to the west coast [21]. ...
... In a sample of 8495 NBA games between 1987 and 1995, west coast teams scored four more points per game (p < 0.05) when traveling to the east coast than east coast teams scored when traveling to the west coast [21]. Furthermore, NBA teams traveling eastward had a winning percentage of 45.4% compared with 36.2% for teams traveling westward (p < 0.001) between 2010 and 2015 [14]. The increased difficulty of traveling westward across the USA to compete has also been reported in the National Football League and the National Hockey League [14]. ...
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Air travel requirements are a concern for National Basketball Association (NBA) coaches, players, and owners, as sport-based research has demonstrated short-haul flights (≤6 h) increase injury risk and impede performance. However, examination of the impact of air travel on player health and performance specifically in the NBA is scarce. Therefore, we conducted a narrative review of literature examining the influence of air travel on health and performance in team sport athletes with suggestions for future research directions in the NBA. Prominent empirical findings and practical recommendations are highlighted pertaining to sleep, nutrition, recovery, and scheduling strategies to alleviate the negative effects of air travel on health and performance in NBA players
... In this regard, NBA players spend more time above 30,000 ft than athletes competing in all other team sports in the United States of America (USA) [7]. Consequently, air travel requirements are a concern for NBA coaches, players, and owners, as research has demonstrated that short-haul flights (e.g., domestic ≤6 h flights) increase injury risk [2,[9][10][11][12][13] and impede performance [9,[14][15][16][17][18][19][20] with more regular or longer periods of travel (e.g., ≥6 h international transfers) more likely to result in negative responses [21,22]. In this chapter, we aim to provide a comprehensive summary of scientific evidence about air traveling on five critical aspects: (1) fatigue, (2) athletic performance, ...
... The direction of air travel should be considered by NBA teams as traveling westward exacerbates reductions in performance [14,23]. In a sample of 8495 NBA games between 1987 and 1995, west coast teams scored four more points per game (p < 0.05) when traveling to the east coast than east coast teams scored when traveling to the west coast [23]. ...
... In a sample of 8495 NBA games between 1987 and 1995, west coast teams scored four more points per game (p < 0.05) when traveling to the east coast than east coast teams scored when traveling to the west coast [23]. Furthermore, NBA teams traveling eastward had a winning percentage of 45.4% compared with 36.2% for teams traveling westward (p < 0.001) between 2010 and 2015 [14]. The increased difficulty of traveling westward across the USA to compete has also been reported in the National Football League and the National Hockey League [14]. ...
Chapter
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Long-distance traveling is a concern for professional basketball coaches, players, and owners, as sport-based research has demonstrated that short-haul flights (≤6 h) increase injury risk and impede performance. However, examination of the impact of air travel on players’ health and performance specifically in the National Basketball Association of the United States of America (NBA) is scarce. Therefore, this chapter examines the literature pertaining to the influence of air travel on health and performance in team sport athletes with suggestions for future research directions in NBA basketball. Prominent empirical findings and practical recommendations are highlighted pertaining to sleep, nutrition, medication, recovery, and scheduling strategies to alleviate the negative effects of air travel on health and performance in elite basketball players.
... Performance decrements have been linked to disruptions in circadian rhythms, which contribute to feelings of jet lag, with symptoms including decreased alertness, insomnia, gastrointestinal distress, fatigue, headaches, impaired sleep, and loss of concentration and motivation [187][188][189]. For players in the NBA, the main disturbances in performance occur when traveling from the East Coast to West Coast [190,191]. Roy and Forest reported that from 2010 to 2015, NBA teams traveling westward had a significantly lower winning percentage (36.2%) compared to teams traveling eastward (45.4%) [190]. ...
... Roy and Forest reported that from 2010 to 2015, NBA teams traveling westward had a significantly lower winning percentage (36.2%) compared to teams traveling eastward (45.4%) [190]. Steenland and Deddens [191] also reported that NBA teams traveling from west to east performed better, scoring 4 more points per game compared to teams traveling from East Coast to West Coast. ...
... Steenland and Deddens [191] also reported that NBA teams traveling from west to east performed better, scoring 4 more points per game compared to teams traveling from East Coast to West Coast. However, these studies did not account for the quality of the teams in the study [190,191]. It has been suggested that performance is diminished from westward travel due to playing at a time players would likely be resting or preparing to sleep [190,191]. ...
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Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players’ recovery for training and competition throughout the season.
... For example, optimizing the schedule for the frequent travel of professional sports team may be out of the scope for sport events, but it is a key aspect for teams to perform effectively on the field. For professional basketball players in the USA, for example, having 82 games in the regular season, which equals to slightly over three games a week in potentially four time zones, a non-optimized travel schedule may affect the winning percentages and the performance of players in the match (Huyghe et al., 2018;Roy and Forest, 2018). The final key pillar for sports logistics managers reflects the classical tasks of logistics services: the transportation process of the required equipment for athletes, venues and fans. ...
... In contrast, Bamford and Dehe (2016) used the London 2012 Paralympic Game to investigate the specific service requirements of disabled athletes during the sports events. With a different focus in their works, Roy and Forest (2018) and Huyghe et al. (2018) combined athlete management with the analysis of sleeping patterns. While not specifically investigating the logistics aspect of athlete air travel, this aspect was listed as one part of the factors that may lead to reduction of winning percentages in the analysis of athletes across three major leagues, i.e. ...
Article
Purpose-Although logistics management is a crucial part of local and global sports events, there is no research-driven characterization of "sports logistics management". The purpose of this paper is to conceptualize a framework that allows for a more structured recognition of logistics in sports, in general, and sport event management, in particular. In addition, we conduct a systematic literature review of sports logistics management and locate opportunities for future research both for sports management and logistics management scholars. Design/methodology/approach-Guided by Durach et al.'s (2017) systematic literature review approach, we identify key attributes and characteristics of sports logistics management. These are based on studies featuring at least partial aspects of logistics management in sports and sport events, and that were published between 2000 and mid-2019. Findings-The study reveals that sports logistics management-meaning logistics activities in sports and sport event management-is a heavily under-researched area that provides an abundance of scientific opportunities. Based on the three sport event types of local/regional sport events, major sport events and mega sport events, the authors propose four sports logistics management pillars that are central to the proposed Sport Logistics Framework: venue logistics management, sports equipment logistics management, athletes logistics management, and fan and spectators logistics management. Practical implications-By providing a conceptual framework for sports logistics, the authors progress towards informing the sport sector on relevant strategic and operational levels of logistics management and set the stage for empirical studies that are likely to advance sport logistics planning and management. Originality/value-This is the first study that builds on a systematic review of literature specifically focused on the logistics aspect in sports and sport event management. It provides a conceptual framework of sports logistics management and offers an agenda of future research opportunities.
... Specifically, when teams are required to travel between different time zones are more affected by this factor. 23 This tendency was especially evident during the second half of the season, suggesting that travel and game frequency costs accrue throughout the season. 24 However, Nutting and Price 25 found that since the turn of this millennium, NBA teams experienced non-significant effects of playing in different time zones, which suggests that the franchises may have begun preparing their players for travels' adverse effects. ...
... Thus, this result suggests that other factors may play a specific role for an optimal adaptation of top-level basketball players to the possible detrimental effect of these contextual variables. 13,20,23 Top-level teams have promoted a greater sophistication of physical, injury prevention, technical and tactical to create favorable conditions to overcome the effect of these contextual constraints. 25,30 Conclusions In summary, these results indicate that as higher the competitive level as narrower the spectrum of possible performance profiles that demands the competition. ...
Article
The aim of this study was two-fold: (i) to identify differences in the game performance profiles of basketball players in Euroleague and European national championships; and (ii) to analyse the influence of player-related (e.g. age or court-position) and contextual variables (e.g. distance travelled or game break) in players’ game-related statistics. Archival data from 2014/2015 and 2015/2016 seasons (n = 16,268 individual game performance records) of Euroleague and European national championships were separately analyzed using a two-step cluster model and then a discriminant analysis to differentiate the obtained groups. The clustering process allowed identifying three and five different performance player profiles for Euroleague and national championships, respectively. The discriminant analysis identified differences in Euroleague playing profiles, particularly related to performers’ age and court-position. In national championships, this trend was not observed. Regardless of the competition, a relationship was perceived between players’ performance and minutes played; conversely, the players’ performance seems to not be affected by contextual variables. The current results provide evidence of different players’ profiles in elite basketball to coaches regarding the influence of player-related and contextual variables. Coaching staffs may account for this information for better management and understanding of their team composition when playing in different competitions.
... This includes e.g., the provision of equipment on matchday and during training, but may also relate to the optimization of the travel schedule for professional sports teams which is considered a precondition for teams to perform effectively on the field (Huyghe, Scanlan, Dalbo, & Calleja-Gonz alez, 2018). For example, travel schedules have an impact on sleeping patterns, which in turn was identified as one part of the factors that may lead to reduction of winning percentages, e.g., in the NFL (Roy & Forest, 2018). The last component of the SLF is equipment logistics management, which reflects the classical tasks related to transportation processes of the required equipment for athletes, venues and fans. ...
... while the winning percentage for all other was 40 points higher with at .438. Roy and Forest (2018) link these reduced winning percentages to sleeping patterns and some NFL teams hire sleep experts for scheduling, as not every flight window allows players to sleep (Orr, 2016). To address the sleep issues, the Dallas Cowboys partnered with "Sleep Well," a provider who not only offers tailored beds, but also provides the technology to monitor heart rate, breathing and movement of players throughout the night (Ogus, 2019). ...
Article
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Global, national and regional sport organizations heavily rely on logistics management practices in their operations. However, scientific research in sports logistics is in its infancy, with conceptu-alizations of the sport logistics domain proposed only recently. In response and by using a reoccurring professional sport event as a case, this study applies the Sports Logistics Framework (SLF) to systematically assess logistics activities, organizational structures, resources and components. Based on semi-structured interviews, unstructured participant observation, internal documents and additional secondary data, our findings not only provide insights into the logistics operations behind a matchday of one of the leading and most valuable sport competitions in the world, but also contextualize, illustrate and refine the logistical tasks of the SLF, thereby providing a template which can be used for further comparison and examination of logistics activities at similar sport events.
... By comparing metrics across time zones relative to travel within a time zone, and not just compared to the home arena, we were able to control for the general influence of travel and thereby examine potential circadian influences. Similar to previous reports, we observed that winning was impacted by westward travel 16,17 , however we can now hypothesize that this may be in part due to reductions in shooting accuracy by the away team. Moreover, examinations of home-advantage have identified increased points scored 18 at home versus away, which is related to shooting accuracy and is in accordance with our findings of increased defensive rating as compared to home. ...
... The sports league with the most similarities to the NBA schedule is the National Hockey League (NHL), which also consists of 82 regular-season games and an approximate 90% overlap in the actual months in which they play (October to June). The NHL also has other similarities to the NBA such as the indoor arena environment (in fact, many of the NBA teams actually share the same arena as the city's NHL team) and that teams also display a circadian disadvantage when traveling westward 16,22 . Thus, our findings may provide information that could be beneficial to teams beyond professional basketball when developing strategies for performing at the highest level when traveling. ...
Article
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On March 11th, 2020, the National Basketball Association (NBA) paused its season after ~ 64 games due to the Coronavirus 2019 (COVID-19) outbreak, only to resume ~ 5 months later with the top 22 teams isolated together (known as the “bubble”) in Orlando, Florida to play eight games each as an end to the regular season. This restart, with no new travel by teams, provided a natural experiment whereby the impact of travel and home-court advantage could be systematically examined. We show here that in the pre-COVID-19 regular season, traveling across time zones reduces winning percentage, team shooting accuracy, and turnover percentage, whereas traveling in general reduces offensive rebounding and increases the number of points the opposing (home) team scores. Moreover, we demonstrate that competition in a scenario where no teams travel (restart bubble) reduces the typical effects of travel and home-court advantage on winning percentage, shooting accuracy, and rebounding. Thus, home-court advantage in professional basketball appears to be linked with the away team’s impaired shooting accuracy (i.e., movement precision) and rebounding, which may be separately influenced by either circadian disruption or the general effect of travel, as these differences manifest differently when teams travel within or across multiple time zones.
... Previous studies have shown that the amount of sleep is largely influenced by training programs; both early morning workouts [3] and evening training alter sleep duration [4]. Competitions [5], travel [6], and psychological pressure have also been shown to impair athletes' sleep [7]. Additionally, individual sports athletes seem to obtain less sleep than athletes in team sports [8]. ...
... Categorical measures (lists of items and yes-no answers) are presented as counts and percentages. In univariate analyses, the 2-tailed Student test (t-test) for unpaired data, the Chi-square test of independency (two-tailed), and the 2-tailed Fisher's exact test for categorical data were used to analyze the association between the variables of 3 different groups (PSQI (0-5), (6)(7)(8)(9)(10)(11), (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)). A univariate association with p-value inferior to 0.2 was considered as the cut-off for including the variables in the multivariate analysis. ...
Article
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The COVID-19 pandemic has changed our lifestyle, sleep and physical activity habits. This study evaluated the prevalence of poor sleep quality, its disrupters, and the impact of the pandemic in collegiate athletes. We performed a cross-sectional study of collegiate athletes (N = 339, median age: 20 (IQR,19–21) years old, 48.5% female, 47% individual sports) who received a web-based questionnaire in April 2021. This survey included subject characteristics, chronotype, sleep disrupters, the changes due to the pandemic and sleep quality (Pittsburg Sleep Quality Index [PSQI]). A multivariate linear regression was performed to assess the relationship between sleep quality, gender, chronotype, sleep disrupters and the changes to training volume or sleep. Results showed a disrupted sleep quality in 63.7%. One in five students had a total sleep time under 6.5 h per night. Poor sleep quality was significantly correlated with nocturnal concerns related to the pandemic, evening chronotype, female gender, third year of study, caffeine consumption and lack of sleep routine (all p < 0.05). To conclude, poor sleep quality is common in collegiate athletes. Sleep disrupters remain prevalent in the lifestyle habits of this population and may have been exacerbated by changes related to the COVID-19 pandemic. Sleep hygiene should become a major aspect of sports education during the return to post-covid normality.
... 39 Performance decrements after travel across time zones also can be compounded by training or competition times that do not align with the typical circadian rhythms based on the athletes' home time zone. 40,41 In contrast, experiments of sleep extension by a few hours have demonstrated improved performance among collegiate basketball players. 42 In particular, the increment of total objective sleep time, including both nocturnal sleep and daytime naps (110.9 ± 79.7 minutes of additional sleep time) compared to baseline resulted in faster sprint times, increased free throw percentage by 9%, increased 3-point field goal percentage by 9.2% (P < .001), ...
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None: Frequent air travel and the condensed game schedule typical of a National Basketball Association (NBA) teams during the season, often results in accompanying sleep disturbances related to sleep length, sleep quality and sleep timing (with highly harmful impacts on health, both physical and mental). These issues are not only problematic for NBA players, but also the coaches, training staff and management support. In this narrative review, we summarize the detrimental effects that this travel and game schedule could have on NBA team member's sleep, as well as their physical and mental health. Multiple peer-reviewed articles address the role of sleep in athletic performance and health, however, to date, the literature focused on sleep-related issues that are unique to the NBA schedule is scarce. Firstly, this review addresses the impact of the NBA schedule, outlining the number of games, and the travel involved (number of flights, the timing of flights, timings of arrival at destination and hotel), we also outline a typical daily NBA travel schedule, providing the reader a glimpse of what this encompasses. Secondly, we provide a brief overview of sleep science and discuss specific applications related to the NBA. Finally, we provide comment on the unique current situation of the NBA "bubble". Based on this review, there appears to be considerable scope for further investigation of the acute and chronic effects of sleep disturbances concerning the NBA travel and game schedule. Sleep science recommendations need to inform practice, target sleep interventions and personalized protocols designed to enhance sleep health that can be incorporated at the organizational level.
... • Sleep banking between travels and games (Roy and Forest, 2018). ...
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The sentiments and feelings like the aforementioned may clearly affect the balance between happiness and wellness (Calleja-Gonzalez et al., 2018). In that way, coaches focus on respecting, valuing, involving, engaging in dialogue with, listening to, and supporting players, as well as treating them as human beings, giving them the confidence and feelings of responsibility to try (BarkerRuchti et al., 2014). There is a clear need for more research in this area, although some advances were already made by examining empathy using qualitative methods and identifying factors of empathy between athletes and coaches (David and Larson, 2018). Furthermore, a period of constructive reflection considering the relationship between performance analysis and recovery is strongly recommended (Calleja-González et al., 2018). Thus, there is a gap between research and reality (Buchheit, 2017), because players express that they are more fatigued from traveling than from training or competition, which is the focus of this letter.A shift in the approach to sports performance research seems to be necessary. For example, sleep quality and quantity (Gupta et al., 2017), burden associated to traveling (Fowler et al., 2014), chronobiological disturbance (Drust et al., 2005) are often cited as limiting factors of performance in high level sport, and their impact should be considered and assessed. Further, the additive effect or the means by which one factor influence another should be taken into account (Tobias et al., 2013).Elite athletes are exposed to substantial training loads , however, that is only a (small) part of the key determinants of performance. Current trends in expertise describe the concept as a dynamically varying relationship captured by the constraints of the environment and those of the performer of a task (RW.ERROR -Unable to find reference:4304). Using this approach, the context is key and should not be detached from the content, thus, the guidelines for designing and implementation of a training program will benefit from incorporating environmental information, integrated periodization, mental performance, skill acquisition, or nutrition (Mujika et al., 2018). In addition, using the aforementioned methods in combination with athlete monitoring of training, competition and psychological load, and pooled with assessments of recovery, well-being, and illness . It may enable the achievement of enhanced performance levels.Since extended traveling is common in elite sport (Flatt et al., 2019), it is recommended that coaches and applied sports scientists consider the following key points in order to minimize injury risk, enhance recovery, optimize performance and bring down the effect of traveling and sleep disturbance on performance (Vitale et al., 2019):-Monitor external training load (before, during and after competition) using tracking systems (Fox et al., 2017) with the least possible invasion.-Monitor Internal responses using heart rate measures and biomarkers in blood, saliva and/or urine before, during and after competition (Halson, 2014).-Monitor daily sleep quality, sleep duration, and player wellbeing to inform same day adjustments to training and competition workload (Fox et al., 2019).-Arrive early to competition destination in order to include sufficient time on-site to recover from traveling and adjust to new time-zones, altitudes, climates and environments (Lastella et al., 2019).-Avoid environmental changes because changing physical sleep environments may increase susceptibility to altered sleep responses, which may negatively affect performance (Pitchford et al., 2017).-Develop and apply consistent strategies (pre, during and post-traveling) that may help prevent or ease jet lag (Fowler et al., 2014).-Develop and apply an ad-hoc nutrition plan for traveling .Stress on the body is probably cumulative (Issurin, 2009). Therefore, the development of new variables, such as ratios, that might relate player's fatigue, training demands, match performance, environmental conditions, at home or away, could be an interesting open window to explore. Further, the creation and validation of a travel fatigue scale would enhance an understanding of the travelling effect. Also, a scale of mental fatigue (Russell et al., 2019) that informs about the stress derived from training, competition and environmental stress would be most useful.With the increasing popularity of sport, number of contests, and travel demands on the rise, the importance of athlete load monitoring in combination with nutritional programming, implementation of recovery methods, and proper sleep practices cannot be underestimated. Taking these steps will make for a more effective travel experience and support athlete health and playing career longevity. In the same page, rationalizing the use of measurement instruments and procedures seems also a need, as anecdotally suggests that "strict data-led regimes undermine trust and stifle creativity, shackling a player's natural empathy with the game", thus, "it is vital that those who oversee performance in elite sport consider the consequences on players of such intense surveillance". • Bus/plane traveling (seats ergonomic, number of disposable seats in bus/plane).• Seating positions/dangerous seating positions (players education and control).• Muscle activation during traveling.• Intellectual activity during traveling.• Problem with sleep medicaments (hypotonic effects).• Sleep banking between travels and games.• Designing individual players traveling profile.• Plane/bus vibration effect on athlete's bodies.• Plane/bus engine noise stressor effect.
... Recently, findings from Jones, Krischen, Kancharla & Hale 13 demonstrated that players who were tweeting between 11:00pm and 7:00am decreased their shooting success rate by 1.7% on average the following game. The first two studies[29][30] highlight the impact of circadian disruption as a possible detrimental factor on performance, whereas the last study 13 demonstrated that fatigued and sleep restricted players will sub optimally perform the following day. In addition,McHill and Chinoy 7 demonstrated during the 2020 NBA bubble that the typical travel impact was reduced, including the home-court advantage, shooting accuracy and rebounding. ...
Article
Impacts of travel distance and travel direction on back-to-back games in the National Basketball Association (NBA) Jonathan Charest1, Charles H. Samuels1, Celyne H. Bastien2, Doug Lawson1 & Michael A. Grandner3 1Centre for Sleep & Human Performance, Calgary, Alberta, Canada 2School of Psychology, Université Laval, Québec City, Québec Canada 3Department of Psychiatry, University of Arizona, Tucson, Arizona, United-States Introduction: Travel fatigue and circadian disruptions are known factors that can hinder performance in professional athletes. The present exploratory study focused on investigating the impact of travel distance and direction on back-to-back games over the 2013-2020 seasons in the National Basketball Association (NBA). Methods: Data from away and home games of back-to-back sequences, in two different cities, from the 2013 to 2020 seasons in the National Basketball Association were included in this study. Information from every selected game was retrieved from the official website of the NBA (www.nba.com). The outcomes were based on winning percentage with additional covariates including the direction of travel (eastward or westward) and the distance travelled (0-500km – 501-1000km – 1001-1500km – 1501km and more). If a team played both games of a back-to-back sequence on the road, they were considered Away-Away; if a team played the first game of a back-to-back sequence at home they were considered Home-Away; if a team played the first game of a back-to-back sequence on the road they were considered Away-Home. Results: The sequence Away-Home significantly increases the likelihood of winning compared to the Away-Away and Home-Away sequences 54.4% (95%CI: 54.4,54.5); 39.2% (95%CI: 37.2,41.2), and 36.8%, (95%CI: 36.7,36.8), respectively. Following a road game, when teams travel back home, every additional 500km reduces the likelihood of winning by approximately 4% (p = 0.038). Finally, after withdrawing the Away-Home sequence, travelling eastward significantly increases the chance of winning (p = 0.024) compared to westward travel but has no significant impact on the probability of winning compared to neutral time zone travel (p = 0.091). Conclusion: The accumulation of travel fatigue and the chronic circadian desynchronization that occurs over the NBA season can acutely disturb sleep and recovery. It appears that tailored sleep and recovery strategies need to be dynamically developed throughout the season to overcome the different challenges of the NBA schedule.
... Navarro et al. [19] examined the effects of concussions on individual players in the National Hockey League (NHL) by assessing career length, performance and salary. Other authors used positional comparisons to assess the impact of fatigue on movement patterns in hockey [20], the utility of using visible signs (VS) of concussion in predicting a subsequent diagnosis of concussion in players [21] and other aspects of the NHL, especially in terms of health impacts on players [22,23]. ...
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The presented research focuses on the commonly used Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), which is applied to an evaluation of a basic set of 581 national hockey league (NHL) players in the 2018/2019 season. This is used in combination with a number of objective methods for weighting indicators for identifying differences in their usage. A total of 11 indicators with their own testimonial values, including points, hits, blocked shots and more, are selected for this purpose. The selection of a method for weighting indicators has a major influence on the results obtained and the differences between them, and maintains the internal links within the ranked set of players. Of the evaluated methods, we prefer the Mean Weight method, and we recommend that the input indicators be considered equivalent when evaluating athletes.
... Furthermore, the majority of back-to-back situations consist of two away games, requiring travel, which may impair athletes' ability to recover between games. Previous research suggests that travel can affect NHL game outcomes (1). Also, data from professional basketball (2) and soccer (3) suggests between-game rest can affect game outcomes. ...
... Some empirical research supports the optimal timing hypothesis. For example, westward travel was negatively associated with winning percentages in the National Basketball Association (NBA) (McHill and Chinoy, 2020), National Hockey League (NHL), and National Football League (NFL) (Roy and Forest, 2018) and eastward travel was positively associated with winning percentages in MLB (Winter et al., 2009). However, individual variability in circadian phenotype has been shown to result in different diurnal physiological and performance profiles, which may skew results that do not account for these differences (Facer-Childs and Brandstaetter, 2015;Facer-Childs et al., 2018). ...
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Objectives: Elite athletes are often required to travel across time zones for national and international competitions, causing frequent jet lag. The aim of this study was to examine whether the direction of travel-related jet lag is associated with performance in the National Basketball Association (NBA), and if so, to explore potential mechanisms. Methods: Ten seasons comprising of 11,481 games of NBA data from the 2011/2012 to the 2020/2021 regular season were analyzed using multi-level mixed models with one fixed factor (three levels; jet lag direction: eastward vs westward vs no jet lag) and three random factors (team, opponent, game time). Predicted circadian resynchronization rate was accounted for, and home and away games were analysed separately. Mediation analyses were performed to examine potential mechanisms. Results: Among home teams, eastward (but not westward) jet lag was associated with reduced winning (Δ (i.e., change) = −6.03%, p = 0.051, marginal), points differential (Δ = −1.29 points, p = 0.015), rebound differential (Δ = −1.29 rebounds, p < 0.0001), and effective field goal percentage differential (Δ = −1.2%, p < 0.01). As the magnitude of eastward jet lag increased, home team points differential decreased (2 h Δ = −4.53 points, p < 0 . 05; 1 h Δ = −0.72 points, p = 0.07). No significant associations were found between jet lag and away team performance. Conclusion: Eastward jet lag was associated with impaired performance for home (but not away) teams. Sleep and circadian disruption associated with advancing phase following eastward travel may have significant adverse consequences on performance in the NBA, particularly when recovery time is limited. Sports organisations could consider chronobiology-informed scheduling and interventions to maximise recovery and performance of their athletes.
... In addition to the impact from the physical act of travelling, the effects of circadian misalignment and time zone changes are also an important consideration [5,38]. Indeed, negative associations between the number of time zones crossed and mood have previously been reported in elite athletes [39], while studies in the NBA found that westward travel negatively impacted winning percentages [26,40]. However, previous research has commonly separated travel-induced fatigue from jet-lag fatigue, with the main difference being that jet-lag fatigue comprises an effect of time zone change while travel fatigue is driven by factors such as regularity, duration and conditions of travel [41]. ...
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This study examined associations between cumulative training load, travel demands and recovery days with athlete-reported outcome measures (AROMs) and countermovement jump (CMJ) performance in professional basketball. Retrospective analysis was performed on data collected from 23 players (mean±SD: age = 24.7±2.5 years, height = 198.3±7.6 cm, body mass = 98.1±9.0 kg, wingspan = 206.8±8.4 cm) from 2018–2020 in the National Basketball Association G-League. Linear mixed models were used to describe variation in AROMs and CMJ data in relation to cumulative training load (previous 3- and 10-days), hours travelled (previous 3- and 10-day), days away from the team’s home city, recovery days (i.e., no travel/minimal on-court activity) and individual factors (e.g., age, fatigue, soreness). Cumulative 3-day training load had negative associations with fatigue, soreness, and sleep, while increased recovery days were associated with improved soreness scores. Increases in hours travelled and days spent away from home over 10 days were associated with increased sleep quality and duration. Cumulative training load over 3 and 10 days, hours travelled and days away from home city were all associated with changes in CMJ performance during the eccentric phase. The interaction of on-court and travel related stressors combined with individual factors is complex, meaning that multiple athletes response measures are needed to understand fatigue and recovery cycles. Our findings support the utility of the response measures presented (i.e., CMJ and AROMs), but this is not an exhaustive battery and practitioners should consider what measures may best inform training periodization within the context of their environment/sport.
... As an example, Fothergill, Wolfson, and Neave (2017) reported hormonal shifts in home versus away games in elite soccer, with home teams demonstrating higher cortisol levels (i.e., greater stress). Other psychobiological work by Roy and Forest (2018) examined the effects of a circadian disadvantage (i.e., playing in a different time zone) on the winning percentages in three major sport leagues in North America (i.e., NBA, NHL, and NFL). The results revealed an association between winning percentages and the number of time zones travelled for the away evening games, with a clear disadvantage for the teams travelling westward. ...
Article
Although researchers have offered insights across a range of topics (e.g., cohesion, leadership, roles, etc.), a recent review suggested that the field of group dynamics in physical activity has a strong potential for growth as an area of focus for research (Eys & Spink, 2016). The objectives of the present review are to (a) highlight the importance of group dynamics within physical activity contexts, (b) review progress made on select but key longstanding and emerging topics, and (c) provide suggestions for future research that will facilitate the progression of the field. To this end, a case is made for the necessity to understand group dynamics based on the prevalence of groups in sport and exercise contexts, in addition to the potential for satiating the fundamental need to belong (Baumeister & Leary, 1995). Finally, key topics and future research directions are embedded within four broad sections including (a) setting the stage (e.g., the group environment, team selection, and socialization), (b) structural issues (e.g., roles, leadership), (c) group processes and emergent states (e.g., cohesion), and (d) the application of group dynamics principles. Overall, there are tremendous opportunities for researchers to contribute to the theory, research, and practice of group dynamics in sport and exercise.
... Actually, athletes' sleep is often disturbed and it is seems challenging to reach optimal levels of sleep quality and quantity (Leeder et al., 2012). Indeed, long travels, different sleeping environments, anxiety, elevated training loads, and many other factors are able to negatively influence the nocturnal rest (Roy and Forest, 2018). Late-night competitions or training sessions could be tricky too for athlete's sleep but results are controversial: it was reported that late-night soccer training did not affect athletes' nocturnal heart-rate-variability (Costa et al., 2018) or sleep behavior (Robey et al., 2014) while, on the contrary, Vitale et al. (2018) showed that elite volleyball players worsened their sleep quality and perceived recovery following a night game. ...
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Purpose: The aim of this study was to investigate objective and subjective sleep quality, daytime tiredness and sleepiness in response to a late-evening high intensity interval training (HIIT) session in neither-type soccer players that habitually trained late in the day. This is the first study that considered both athletes’ chronotype and habitual training time as crucial factors when assessing sleep quality in relation to an evening physical task. Methods: In this longitudinal, prospective, observational study, 14 Italian soccer players were recruited (mean age: 26.1 ± 4.5 years; height: 1.81 ± 0.06 m; weight: 78.9 ± 6.1 kg) and performed an extra-routine 4 × 4-min HIIT session at 09:00 p.m. Players used to train always between 09:00 and 11:00 p.m during the competitive season. All subjects wore an actigraph to evaluate their objective sleep parameters and a sleep diary was used to record subjective values of sleep quality, daytime tiredness, and daytime sleepiness. All data were analyzed as: the mean of the two nights before (PRE), the night after (POST 1), and the mean of the two nights after (POST 2) the extra-routine HIIT session. The subjects’ chronotype was assessed by the morningness-eveningness questionnaire (MEQ). Results: All players were classified as N-types (mean MEQ score: 49.4 ± 3.7). None of the actigraph parameters nor the subjective values of sleep quality, tiredness, and sleepiness showed significant changes in PRE, POST 1, and POST 2. Conclusion: The results of our study added more information regarding sleep quality outcomes in response to a late-evening HIIT session. Athletic trainers and medical staff should always control for chronotype and habitual training time when assessing variations to sleep quality in athletes.
... A study that used recent data from the NBA and NHL confirmed that visiting teams that traveled westward had significantly lower winning percentages than did teams that traveled eastward. This phenomenon was more apparent in evening games and when visiting teams traveled across more time zones (Roy and Forest, 2018). These results indicated that, in addition to fatigue, travel results in a circadian disadvantage to visiting teams, which can be advantageous to home teams. ...
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A home advantage is present in most professional sports leagues. Spectators may be a major factor in home advantage, but empirical results have been mixed. Professional games were played without spectators during the 2020 season amid the COVID-19 pandemic. This study investigated home advantage in Major League Baseball (MLB) during 2020 as compared with the 2015–2019 seasons. A total of 13,044 regular-season games (898 in 2020 and 12,146 in 2015–2019) were analyzed. The sum of wins above replacement of all players was used as an indicator of team quality. The likelihood of a home-team win with spectators was not significantly different to that without spectators (odds ratio = 1.068; 95% confidence interval = 0.932–1.224, p > 0.05). The relative home advantage, percentage of home wins of total wins by a team in a specific season, was not significantly different across years, team quality, and attendance. Factorial analysis of variance models that included the variables of year, team quality, and attendance also revealed that none of these variables significantly affected the relative home advantage. The results suggest that spectators may not be an important factor of home advantage in MLB.
... The inclusion of the opponent's PIR and PTC scores in the analyses would help to conclude if these results can be extrapolated to all basketball players or if they are just a characteristic of the examined team. To the author's knowledge, only one study in basketball have included the game time (day and evening games) as a contextual factor to detect differences in winning probabilities during NBA games (Roy & Forest, 2018) and concluded a relationship between the winning percentages and the number of time zones traveled for the away evening games. ...
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The purpose of the study was to examine the relationships of different training load variables and wellness responses, with in-game basketball performance across playing positions (backcourt and frontcourt players). External load variables (e.g., total distance, accelerations, etc), internal responses (e.g., rate of perceived exertion [RPE]) and wellness status (e.g., Hooper index) were monitored during 7 consecutive in-season months on 15 professional male basketball players. Besides, game-related individual statistics (performance index rating [PIR], and player total contribution [PTC]) were used to assess the performance during competition. Although no positive relationship was found between training load variables and basketball game performance, some wellness questionnaire parameters were significantly associated to game-related individual statistics. In particular, we found that only competing against direct rivals, players that reported stable values of stress stability achieved significantly higher PTC and PIR scores than players with high variability in stress values (8.53 IQR [6.09, 14.8] vs 0.00 IQR [-0.46, 0.84], and 0.47 ± 0.40 vs 0.10 ± 0.50; respectively; P < 0.05). Similarly, players with variable values of stress managed to maximize PIR scores during losses compared to players that presented high variability in stress levels (0.42 IQR [0.27, 0.55] vs 0.00 IQR [-0.12, 0.37], P < 0.05). Regarding playing positions, backcourt players showed higher PTC scores compared to frontcourt players when the fatigue levels are stable during the microcycle (8.27 ± 5.75 vs 4.77 ± 4.42; P < 0.05). Because basketball teams tend to accumulate more backcourt players that frontcourt players, it would be advisable to control training load maintaining it stable and avoiding load spikes during microcycle to allow team performance optimization. In conclusion, the results suggest that the best performances during official competition are not associated with higher training external and internal loads. Nevertheless, the wellness status could provide useful information when assessing player’s training responses and approaching possible peak performance during basketball competition. This shows the necessity to assess basketball performance from a holistic approach and consider more than just physical and physiological parameters, such as decision-making and psychological capacities, to better understand player’s performance during basketball competition.
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Air travel requirements are a concern for National Basketball Association (NBA) coaches, players, and owners, as sport-based research has demonstrated short-haul flights (≤6 h) increase injury risk and impede performance. However, examination of the impact of air travel on player health and performance specifically in the NBA is scarce. Therefore, we conducted a narrative review of literature examining the influence of air travel on health and performance in team sport athletes with suggestions for future research directions in the NBA. Prominent empirical findings and practical recommendations are highlighted pertaining to sleep, nutrition, recovery, and scheduling strategies to alleviate the negative effects of air travel on health and performance in NBA players.
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During the National Basketball Association (NBA) playoffs, teams are required to frequently travel to different venues to play opponents in series of up to seven games. Despite playoff schedules allowing for some rest between games, it is still possible for teams to face circadian misalignment when playing. Thus, the current study serves as a replication and extension of previous research, which has indicated that there is an advantage for teams playing closer to their circadian peak and when they are traveling east. This study specifically investigates the effects of travel, as well as time of game on various performance indicators in professional basketball. We examined a series of box-score statistics (e.g., game outcomes, points scored, shooting percentages, rebounds, assists, steals, blocks, turnovers, and personal fouls) from a total of 499 postseason games played between the 2013–14 and 2018–19 NBA seasons. Findings from our study indicate that teams traveling eastward scored more points than teams traveling within the same time zone. We also observed that teams playing evening games had higher three-point shooting percentages than teams playing in the afternoon. Our study demonstrates an extended impact of travel and time of day on more specific performance indicators in the NBA. Future directions and implications for professional basketball and other sports are discussed.
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Background Particularly at the level of professional athletics, injury prevention is of critical importance. We hypothesized that elevated in-game statistics over a period of 3-10 games places increased cumulative stress on players’ joints and thus predisposes players to injury. Methods Utilizing a comprehensive database of National Basketball Association (NBA) player statistics, we identified 34 NBA players who suffered significant in-game injuries during the 2016-2019 seasons, leading them to miss at least ten consecutive games. We then assessed several potential markers of increased player workload during the cumulative one, three, five, and ten games directly preceding the injuries and compared them to season averages for each player. Results Increased minutes played per game over the cumulative three (4.9% increase, p = 0.04), five (5.8% increase, p = 0.004), and ten (4.0% increase, p = 0.02) games directly preceding injury were closely related to increased injury occurrence. In-game activity level as measured by statistics such as points scored and rebounds per game did not relate to injury occurrence. Conclusion In addition to injury mitigation practices currently used by NBA teams, maintaining players’ minutes played per game constant over time may be an additional effective strategy to be used by coaches and general managers in the future.
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ABSTRACT Elite athletes are particularly susceptible to sleep inadequacies, characterised by habitual short sleep (<7 hours/night) and poor sleep quality (eg, sleep fragmentation). Athletic performance is reduced by a night or more without sleep, but the influence on performance of partial sleep restriction over 1–3 nights, a more real-world scenario, remains unclear. Studies investigating sleep in athletes often suffer from inadequate experimental control, a lack of females and questions concerning the validity of the chosen sleep assessment tools. Research only scratches the surface on how sleep influences athlete health. Studies in the wider population show that habitually sleeping <7 hours/night increases susceptibility to respiratory infection. Fortunately, much is known about the salient risk factors for sleep inadequacy in athletes, enabling targeted interventions. For example, athlete sleep is influenced by sport-specific factors (relating to training, travel and competition) and non-sport factors (eg, female gender, stress and anxiety). This expert consensus culminates with a sleep toolbox for practitioners (eg, covering sleep education and screening) to mitigate these risk factors and optimise athlete sleep. A one-size-fits-all approach to athlete sleep recommendations (eg, 7–9 hours/night) is unlikely ideal for health and performance. We recommend an individualised approach that should consider the athlete’s perceived sleep needs. Research is needed into the benefits of napping and sleep extension (eg, banking sleep).
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Objectives Examine Australian Football League (AFL) results for evidence that game-day circadian misalignment or environmental temperature influence games with competing teams from each of Western Australia (WA) and Victoria (VIC). Design Retrospective observational study. Methods Data were obtained for games (n = 791) contested by WA and VIC teams; including game location, start time, and outcome. Start times were categorised as afternoon, twilight, or night. Game-day maximum temperature (°C) for afternoon games were obtained from the Australian Bureau of Meteorology. Mixed effects generalised linear models examined evidence for a circadian advantage to VIC teams in afternoon games, and to WA teams in night games. Models examined evidence for an advantage to WA teams as game-day temperature increases. Results Odds of winning and point margin for home games played in the afternoon, twilight, and night, were not different between VIC and WA teams (p > 0.05). For afternoon games, each 1 °C increase in temperature improved odds of WA teams winning by 11% (p < 0.001) and their point margin by 2.1 points (p < 0.001). For games played in VIC, each 1 °C increase in temperature improved odds of WA teams winning by 6% (p = 0.028) and their point margin by 1.7 points (p = 0.005). Conclusions There was no evidence that circadian misalignment between teams influenced game outcomes. For afternoon games, WA teams are more likely to win, and have improved point margins, as temperature increases. Improved outcomes for WA teams as temperatures increase may reflect the benefits of heat acclimatisation.
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Timing is everything. It allows us to anticipate the best time to conserve energy, identify the time of peak performance, recognise when attention may be sub-optimal, and find the most effective time for nutritional intake. The study of timing and cyclic phenomena in humans is termed human chronobiology (chrono= time) and has many implications for the elite athlete.
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Introduction Travel fatigue and circadian disruptions are known factors that can hinder performance in professional athletes. The present exploratory study focused on investigating the impact of travel distance and direction on back-to-back games over the 2013–2020 seasons in the National Basketball Association (NBA). Methods Data from away and home games of back-to-back sequences, in two different cities, from the 2013 to 2020 seasons in the National Basketball Association were included in this study. Information from every selected game was retrieved from the official website of the NBA (www.nba.com). The outcomes were based on winning percentage with additional covariates including the direction of travel (eastward or westward) and the distance travelled (0-500km – 501-1000km – 1001-1500km – 1501km and more). If a team played both games of a back-to-back sequence on the road, they were considered Away-Away; if a team played the first game of a back-to-back sequence at home they were considered Home-Away; if a team played the first game of a back-to-back sequence on the road they were considered Away-Home. Results The sequence Away-Home significantly increases the likelihood of winning compared to the Away-Away and Home-Away sequences 54.4% (95%CI: 54.4,54.5); 39.2% (95%CI: 37.2,41.2), and 36.8%, (95%CI: 36.7,36.8), respectively. Following a road game, when teams travel back home, every additional 500km reduces the likelihood of winning by approximately 4% (p = 0.038). Finally, after withdrawing the Away-Home sequence, travelling eastward significantly increases the chance of winning (p = 0.024) compared to westward travel but has no significant impact on the probability of winning compared to neutral time zone travel (p = 0.091). Conclusion The accumulation of travel fatigue and the chronic circadian desynchronization that occurs over the NBA season can acutely disturb sleep and recovery. It appears that tailored sleep and recovery strategies need to be dynamically developed throughout the season to overcome the different challenges of the NBA schedule. Support (if any):
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Travel across time zones may affect player scoring through circadian rhythm. We test how travel affects scoring for the US National Basketball Association from 2014–2018, a period featuring a new game scheduler. We also test whether a collective bargaining agreement that protected player rest changed how travel affects scoring. We find eastward travel increases scoring and point spread via three-pointers and field goals, with implications for point spread betting in sports gambling markets. The 2017 collective bargaining agreement mitigates the eastward travel benefit on scoring and increases scoring overall, suggesting improved fairness and potential benefits for players and fans.
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We hypothesized that professional football teams would perform better than anticipated during games occurring close to their circadian peak in performance. We reviewed the past 40 years of evening and daytime professional football games between west coast and east coast United States teams. In order to account for known factors influencing football game outcomes we compared the results to the point spread which addresses all significant differences between opposing teams for sports betting purposes. One sample t-tests, Wilcoxon signed ranked tests, and linear regression were performed. Comparison to day game data was included as a control. Academic medical center. N/A. N/A. The results were strongly in favor of the west coast teams during evening games against east coast teams, with the west coast teams beating the point spread about twice as often (t = 3.95, P < 0.0001) as east coast teams. For similar daytime game match-ups, we observed no such advantage. Sleep and circadian physiology have profound effects on human function including the performance of elite athletes. Professional football players playing close to the circadian peak in performance demonstrate a significant athletic advantage over those who are playing at other times. Application of this knowledge is likely to enhance human performance. Smith RS; Efron B; Mah CD; Malhotra A. The impact of circadian misalignment on athletic performance in professional football players. SLEEP 2013;36(12):1999-2001.
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The risk of adverse cardiovascular events peaks in the morning (≈9:00 AM) with a secondary peak in the evening (≈8:00 PM) and a trough at night. This pattern is generally believed to be caused by the day/night distribution of behavioral triggers, but it is unknown whether the endogenous circadian system contributes to these daily fluctuations. Thus, we tested the hypotheses that the circadian system modulates autonomic, hemodynamic, and hemostatic risk markers at rest, and that behavioral stressors have different effects when they occur at different internal circadian phases. Twelve healthy adults were each studied in a 240-h forced desynchrony protocol in dim light while standardized rest and exercise periods were uniformly distributed across the circadian cycle. At rest, there were large circadian variations in plasma cortisol (peak-to-trough ≈85% of mean, peaking at a circadian phase corresponding to ≈9:00 AM) and in circulating catecholamines (epinephrine, ≈70%; norepinephrine, ≈35%, peaking during the biological day). At ≈8:00 PM, there was a circadian peak in blood pressure and a trough in cardiac vagal modulation. Sympathetic variables were consistently lowest and vagal markers highest during the biological night. We detected no simple circadian effect on hemostasis, although platelet aggregability had two peaks: at ≈noon and ≈11:00 PM. There was circadian modulation of the cardiovascular reactivity to exercise, with greatest vagal withdrawal at ≈9:00 AM and peaks in catecholamine reactivity at ≈9:00 AM and ≈9:00 PM. Thus, the circadian system modulates numerous cardiovascular risk markers at rest as well as their reactivity to exercise, with resultant profiles that could potentially contribute to the day/night pattern of adverse cardiovascular events.
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The effect of travel on athletic performance has been investigated in previous studies. The purpose of this study was to investigate this effect on game outcome over 10 Major League Baseball (MLB) seasons. Using the convention that for every time zone crossed, synchronization requires 1 d, teams were assigned a daily number indicating the number of days away from circadian resynchronization. With these values, wins and losses for all games could be analyzed based on circadian values. 19,079 of the 24,121 games (79.1%) were played between teams at an equal circadian time. The remaining 5,042 games consisted of teams playing at different circadian times. The team with the circadian advantage won 2,620 games (52.0%, P = .005), a winning percentage that exceeded chance but was a smaller effect than home field advantage (53.7%, P < .0001). When teams held a 1-h circadian advantage, winning percentage was 51.7% (1,903-1,781). Winning percentage with a 2-h advantage was 51.8% (620-578) but increased to 60.6% (97-63) with a 3-h advantage (3-h advantage > 2-hadvantage = 1-h advantage, P = .036). Direction of advantage showed teams traveling from Western time zones to Eastern time zones were more likely to win (winning percentage = .530) than teams traveling from Eastern time zones to Western time zones (winning percentage = .509) with a winning odds 1.14 (P = .027). These results suggest that in the same way home field advantage influences likelihood of success, so too does the magnitude and direction of circadian advantage. Teams with greater circadian advantage were more likely to win.
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A home advantage in sport competitions has been well documented. The strength and consistency of the home advantage has made it a popular phenomenon in sport today. Very little systematic research has been carried out, however, and the home advantage remains one of the least understood phenomena in sport. It appears that much of the game location research has been arbitrary, and a clear sense of direction is lacking. The purpose of the present paper is to provide a conceptual framework to organize a comprehensive review of previous game location research and provide direction for future research. The review of literature indicated that the descriptive phase of inquiry has been completed, and it is time to address the underlying mechanisms responsible for the manifestation of the home advantage. Possible methodologies and areas of inquiry are highlighted and discussed.
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Athletes train and compete at different times of the day according to personal preferences, schedule of team training or timing of competition. Many human performance variables follow the circadian rhythm in physiological measures, in phase with the rhythm in core body temperature. This correspondence applies to components of performance, physiological determinants of performance with high power output, psychophysical loading and competitive time trials. There is evidence that circadian rhythms in exercise performance are, in part, endogenously driven. Human performance rhythms are disrupted when athletes travel rapidly across multiple meridians, or are engaged in nocturnal shift-work. Few sports participants maintain high-performance standards when operating shift-work regimens. In contrast, travelling across time-zones is a contemporary feature of competitive sport for sojourns and training camps and participating in international contests. Athletes like all travellers experience jet lag symptoms when crossing multiple time-zones. Symptoms are worse and last longer following flights to the east compared to flying westwards. Performance rhythms re-adjust to the new local time at about the same time as that of core temperature. Experience with Olympic athletes travelling between Europe and Australia is that adjustment may be by phase advance or phase delay depending on timing of departure and disembarkation, time of arrival and exposure or avoidance of natural light, and activity in the early days in the new time-zone. Adjustment can be assisted by means of a behavioural strategy that combines the body clock and the homeostatic drive to sleep. Exclusion of long naps, the diurnal timing of physical training and social events form part of this strategy, as do eating and drinking behaviour. Exercise is a potential resynchronising agent when utilised at the correct time of day. Pharmacological treatments, including use of melatonin, have found favour in some contexts but their phase response curves pose difficulties for their administration in athletes travelling on long-haul flights. In view of the national governing bodies' stances on use of pharmacological agents and supplements by athletes, the behavioural strategy to cope with jet lag has been advocated.
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To determine the effect of time zone and game time changes on NFL team performance, win-loss records from 1978-1987 were analyzed. Twenty-seven NFL teams were grouped by time zone and possible anti-jet lag adjustments. Among all intra-time zone rivals, home teams won 56.6%, away teams won 43.8%, for a home vs away winning percentage change of -12.8% (P < 0.001). West teams (N = 5) displayed fluctuations in home vs away team performance in association with trans-meridian travel. The change in winning percentage was found to be 0.0% vs West teams, -14.1% vs Central teams (N = 8) (P < 0.05), -16.3% vs East (N = 14) (P < 0.05) for West teams (N = 4) flying about 42 h pregame and +2.3% vs East for the one West team advancing practices 3-4 h to match East coast game time in addition to 48 h pregame flights. For night games within the same time zone, home vs away team winning percentage changed -23.8% (P < 0.01). West teams displayed uniformly high home winning percentages (75.0% and 68.4%) when playing Central and East teams, respectively, with little or no fall in away winning percentages (67.7% and 68.8%). For day games, a 3-h phase advance may decrease West coast team performance. In one small subset, anti-jet lag adjustments appeared to eliminate the expected decrement in performance. For night games, West coast teams, whether home or away, appear to be at a distinct advantage over East and Central teams.
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Circadian rhythms produce daily changes in critical elements of athletic performance. We explored the significance of performing at different circadian times in the National Football League (NFL) over the last 25 seasons. West Coast (WC) NFL teams should have a circadian advantage over East Coast (EC) teams during Monday Night Football (MNF) games because WC teams are essentially playing closer to the proposed peak athletic performance time of day. Retrospective data analysis was applied to all games involving WC versus EC teams playing on MNF with start times of 9:00 p.m. Eastern Standard Time (EST) from the 1970-1994 seasons. Logistic regression analysis of win-loss records relative to point spreads and home-field advantage was examined. West Coast teams win more often (p < 0.01) and by more points per game than EC teams. West Coast teams are performing significantly (p < 0.01) better than is predicted by the Las Vegas odds (the point spread). This apparent advantage enhances home-field advantage for WC teams and essentially eliminates the beneficial effects of home-field advantage for EC teams during MNF games. These results support the presence of an enhancement of athletic performance at certain circadian times of the day.
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This brief review is concerned with how human performance efficiency changes as a function of time of day. It presents an overview of some of the research paradigms and conceptual models that have been used to investigate circadian performance rhythms. The influence of homeostatic and circadian processes on performance regulation is discussed. The review also briefly presents recent mathematical models of alertness that have been used to predict cognitive performance. Related topics such as interindividual differences and the postlunch dip are presented.
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The effects of jet lag are transient and should not entail cessation of athletic training. Symptoms will not cause performers to desist because of exhaustion, as might occur with heat stress, but can hinder quality of training and performance. Rehydration is important, particularly if the ambient temperature in the new time zone is high, as heat stress may be compounded by fluid losses incurred during flight. Behavioral means of coping with jet lag should be sufficient provided the travelers arrive in time to allow the body clock to adjust by the first competition. Because pharmacology has not provided a panacea for overcoming jet lag, a behavioral strategy can be implemented by raising awareness of the issues and by setting guidelines as to the actions required on specific trips and the things to avoid. The educational program should be extended to support staff in addition to the active members of the traveling team. With this background information, the physician can tailor a coping program to the needs and characteristics of an individual athlete.
West coast teams of the NFL have a chronobiologic advantage in winning: assessment of game day travel, turnovers and injuries (abstract)
  • Brager
Brager, A. and Mistovich, R. West coast teams of the NFL have a chronobiologic advantage in winning: assessment of game day travel, turnovers and injuries (abstract). Sleep, 2016, A161.