In elite sport, travel is often discussed as a logistical problem: flight times, hotel arrivals, transport and training schedules. Once the team is home, the journey is assumed to be over.
Physiologically, it may not be.
A new study published in Sports Medicine – Open examined 3,489 regular-season Women’s National Basketball Association (WNBA) games across 18 seasons, from 2007 to 2024. Its findings offer an important reminder for coaches and sport scientists: the distance accumulated on the road and the circadian disruption created by crossing time zones are related but distinct performance challenges, and neither can be understood from location alone.
The study found that away teams performed worse as their recent travel accumulated, while home teams were negatively affected when returning from eastward travel without sufficient time to adjust. Put simply, playing at home did not necessarily mean being biologically back on home time.
What did the researchers examine?
Leota and colleagues set out to answer three questions:
- Has home-court advantage in the WNBA changed over time?
- Is the distance travelled during the previous seven days associated with team performance?
- Does the direction of travel, and the estimated jet lag remaining on game day, matter?
Team performance was assessed using points differential: the difference between points scored and points conceded. The statistical models accounted for several important contextual factors, including game time, the relative strength of the two teams, schedule congestion and performance in the previous game.
Travel distance and jet lag were also treated separately. Cumulative distance represented the miles travelled during the preceding seven days, while directional jet lag estimated the circadian misalignment remaining after eastward or westward travel. For the latter, the researchers assumed an average adjustment rate of one hour per day.
That separation is important. A team can accumulate considerable travel fatigue without crossing a time zone. Equally, a relatively short flight across multiple time zones can create a meaningful circadian challenge. Distance tells us about the journey; time-zone change tells us about the shift being asked of the body clock.
Finding one: home-court advantage has declined
Home teams won 64.3% of games in 2009, when home-court advantage was at its highest during the study period. By 2024, that figure had fallen to 52.3%.
The average home points advantage followed a similar pattern, declining from +4.0 points per game in 2009 to just +0.8 in 2024.
This decline coincided with major improvements in WNBA travel conditions. Players gained enhanced seating and individual hotel rooms under the 2020 collective bargaining agreement, while league-wide charter flights were introduced in 2024.
It is tempting to conclude that better travel caused the reduction in home advantage. The study cannot establish that, and factors such as crowd influence, league parity and structural changes may also have contributed. Nevertheless, the pattern raises an important practical point: improving the travel environment may reduce some of the burden associated with playing away.
More comfortable and reliable travel matters. But the other findings show that better transport does not remove the physiological consequences of repeated travel or rapid time-zone change.
Finding two: accumulated travel was associated with poorer away performance
Among away teams, greater travel distance during the preceding seven days was associated with a worse points differential. For every additional 1,000 miles travelled, teams conceded approximately 0.37 more points on average, after accounting for team strength, game time, jet lag and schedule congestion.
The effect per 1,000 miles was modest. Across a multi-game road sequence, however, the distances and potentially the effects can accumulate. In a league where close games are common, small average differences may still matter.
Interestingly, the association was driven by more points being conceded rather than fewer points being scored.
This does not prove that travel selectively impaired defence. Points conceded could also be influenced by turnovers, fouls, transition opportunities or other aspects of the game. However, the authors offer a plausible explanation: defensive execution frequently depends on sustained attention, rapid reactions, communication and repeated decisions in response to an opponent. These processes may be particularly sensitive to poor sleep and travel-related fatigue. Offensive play, by comparison, can sometimes rely more heavily on rehearsed structures and direction from the sideline.
For practitioners, the lesson is not simply to expect worse defence after travel. It is to recognise that travel-related impairment may become visible in reactive and cognitively demanding parts of performance, not necessarily in headline physical outputs or scoring totals.
Finding three: the return home can still carry a jet-lag penalty
Perhaps the most practically important finding involved home teams.
When teams played at home with estimated eastward jet lag, their average points differential was +0.69, compared with +2.55 when no jet lag was estimated. That represents a difference of 1.86 points per game.
No equivalent association was found after westward travel, or for away teams experiencing directional jet lag.
Eastward travel generally requires the body clock to advance. Athletes must fall asleep, wake and become ready to perform earlier than their current biological timing. Because the human circadian period naturally tends to run slightly longer than 24 hours, advancing is commonly more difficult than delaying after westward travel.
The fact that the association appeared in home teams is particularly interesting. One explanation proposed by the authors is that an away environment can be highly structured: meals, meetings, training, light exposure and sleep opportunities may all be organised around the team. On returning home, players disperse into individual routines, family responsibilities and social commitments, even though their circadian systems may still be adjusting.
This remains a hypothesis rather than a finding directly tested by the study. But it highlights an operational blind spot: teams often manage the outbound journey carefully and assume that returning home completes the recovery process.
Home is a location. Recovery is a physiological state.
The WNBA result is also consistent with the related 2022 NBA study provided alongside this review. That earlier analysis examined 11,481 games across 10 regular seasons and found that eastward jet lag was associated with a 1.29-point reduction in home-team points differential, alongside lower rebound differential and effective field-goal percentage differential. The estimated 6.03% reduction in winning percentage was marginal rather than conventionally statistically significant (p = 0.051), and no significant associations were found among away teams.
The two studies should not be treated as one dataset, and neither proves causation. However, the recurrence of a home-specific eastward association across both the NBA and WNBA strengthens the case for managing the return journey as carefully as the outbound trip.
What should coaches and sport scientists take from the study?
1. Monitor the travel block, not only the latest flight
The relevant exposure in this study was cumulative travel across seven days. Reviewing each journey in isolation can miss the load created by a sequence of flights, hotels, late arrivals and disrupted routines.
Travel should therefore sit alongside training and competition in weekly load discussions. Useful questions include: How far has the team travelled recently? How many transitions and late arrivals were involved? What sleep opportunities were lost? What demanding tasks are scheduled next?
2. Separate travel fatigue from circadian disruption
Distance and directional jet lag produced different associations. They should not be compressed into a single travel-risk label.
Travel fatigue can arise from the journey itself: prolonged sitting, delays, altered meals, unfamiliar environments and sleep loss. Jet lag reflects misalignment between internal biological time and the external time zone. Each requires different management decisions, even though they can occur together.
3. Treat the journey home as part of the performance plan
Returning players may still need structured guidance around sleep timing, light exposure, caffeine, activity and recovery. This is particularly important after eastward travel and when the next home game falls inside the likely adaptation window.
The home fixture should therefore be included in the travel plan, rather than treated as the point at which that plan ends.
4. Give eastward travel greater planning attention
Direction matters. When schedules allow, additional adjustment time after eastward travel may be valuable. When they do not, carefully timed light, darkness, sleep and activity can help move the body clock in the required direction.
Generic instructions such as “get morning light” are often not enough, especially when there is little understanding of circadian phase. Whether light advances or delays the circadian clock depends on its timing relative to the individual’s biological night.
5. Protect the most reactive elements of performance
Where cumulative travel is high, coaches may need to consider how they prepare and assess defensive communication, reaction, decision-making and tactical discipline. A player can complete a physical session while still being less sharp in rapidly changing situations.
This may influence the timing and content of training, tactical meetings and cognitive demands during congested travel periods.
6. Improve the journey, but do not stop there
Charter flights, better seats and improved accommodation can reduce travel stress and uncertainty. They are valuable performance interventions in their own right.
They do not, however, automatically realign the circadian system. Better logistics reduce part of the problem; they do not replace a sleep and circadian strategy.
Important context when interpreting the findings
This was a large and valuable analysis, particularly because research on travel in women’s professional sport remains limited. However, it was observational, so it identifies associations rather than proving that travel or jet lag caused the performance differences.
The researchers also worked from game locations rather than teams’ exact itineraries. Actual departure times, arrival times, training schedules and individual sleep behaviour were unavailable. Jet lag was estimated using a uniform adjustment rate of one hour per day, even though circadian adaptation varies considerably between individuals and trips.
Finally, points differential is a broad team-level outcome. Player-level monitoring and more granular basketball measures would help identify who is most affected and precisely where changes appear.
The reported effects were modest and should not be presented as the sole explanation for game outcomes. Their value lies in showing that travel variables remain meaningfully associated with performance across thousands of games, even after several important contextual factors were considered.
From travel logistics to travel performance
The biggest lesson from this study is not that every additional mile produces a predictable performance loss. It is that readiness after travel depends on more than where the team is playing.
Coaches need to consider the accumulated journey, the direction and timing of time-zone transitions, the recovery opportunity available, the demands of the next performance and the individual athlete’s response. “Home” and “away” are competition labels; they are not measures of circadian readiness.
This is the challenge Phaze is designed to make manageable. By combining team travel and performance context with personalised guidance around sleep, light, caffeine and activity, Phaze helps support athletes before, during and after travel, including the often-overlooked period after they return home.
Because the journey may end at the arrivals hall, but its effect on performance can continue well beyond it.
References
Leota, J., Miller, D. J., Czeisler, M. É., Cook, J., Mascaro, L., Smithies, T. D., Nelthropp, A., & Facer-Childs, E. R. (2026). Home-court advantage and the associations of travel and jet lag with team performance in the Women’s National Basketball Association (WNBA). Sports Medicine – Open, 12, 94. https://doi.org/10.1186/s40798-026-01067-0
Leota, J., Hoffman, D., Czeisler, M. É., Mascaro, L., Drummond, S. P. A., Anderson, C., Rajaratnam, S. M. W., & Facer-Childs, E. R. (2022). Eastward jet lag is associated with impaired performance and game outcome in the National Basketball Association. Frontiers in Physiology, 13, 892681. https://doi.org/10.3389/fphys.2022.892681
Disclosure: WNBA study co-author Dr Tim Smithies is Algorithm Lead at Phaze.