When high-performance teams travel, it is possible to log nine hours of sleep and still underperform. The issue isn’t always total sleep loss or travel fatigue; it’s often when that sleep occurred relative to the state of the body clock – our circadian clock that influences alertness, coordination, decision-making, and athletic output. In travel, timing, not just quantity, determines readiness. Phaze coaches that timing so teams arrive in sync, as well as rested.

 

The practical problem 

• Jet lag traditionally means ≥3 time zones crossed.
• Travel fatigue is the acute stress from the flight and travel (stress, cabin environment, sleep loss).
• Social jet lag is a mismatch between biological preference (chronotype) and imposed schedule.
• Person-to-person variance is the spectrum of chronotypes and sleep behaviours that exist amongst us all. 

 

In the real world, in the days after arrival, these blend into one operational issue: circadian misalignment. Circadian rhythms and time of day strongly influence athletic, physical, and cognitive performance [1;2]. Misalignment can mean performing at the wrong biological time for the task.

 

Proof it affects outcomes

Across sports, performance markers move with the clock:

• Groups of NBA players crossing time zones saw reduced free-throw accuracy (P = .002). [3]
• MLB team’s defensive performance was significantly impacted following eastward travel (P < 0.05). [4]
• Strength, sprint, and jump outputs can decline post-travel (P < 0.05). [5;6;7]

 

Where plans break

Most protocols rely on simple rules: get eight hours, seek bright light in the morning, avoid overnight flights. Sometimes that’s enough. But more often, these broad strategies backfire, re-anchoring the circadian clock to the wrong time.

Take a common example: a team flies five time zones west, from London to New York. The pre-plan is solid; light exposure carefully timed, sleep on the flight, meals set to the destination time. But on arrival, a group heads to bed at 21:00, wakes at 05:00 feeling refreshed, and heads out into the bright morning light for a jog and coffee. That single timing slip locks them back onto London time. By late afternoon, when sharpness is needed most, they crash. And the effect lingers for days.

With the circadian system, near compliance is rarely enough. Small timing mistakes can undo days of preparation.

 

It all starts at “home”

Circadian misalignment isn’t just a long-haul problem. Many people aren’t living on “local time” even before they travel. The issue gets exposed on the road when routines are disrupted and schedules are tight.

Common scenarios:

• A staff member works late into the evening when at home, so even a 1-hour flight, with an eastward shift, may incur jet lag-type symptoms via what is typically labelled as social jet lag.

   

• A squad is never aligned in the first place; several players are habitual late sleepers, already running out of sync with the local zone.

It’s not “classic” jet lag – the shift is fewer than three time zones, but it can feel almost identical. This mix of mild time-zone travel and social jet lag produces the same cocktail of symptoms: fatigue, poor sleep, and reduced performance. Sleep logs can gloss over it. Workload data won’t flag it. But mis-timed rhythms steadily erode output. That’s the invisible tax of travel.

 

Consider Chronotype

Our innate preferences for being a “morning” or “evening” person is rarely factored into team travel planning. Variance exists not just between individuals, but within the same person across their lifetime, making it easy to overlook.

Research has suggested that chronotype and time of day influence performance. Evening types, in particular, tend to perform worse in the mornings compared to morning types, across most physical and cognitive domains [8;9]. The relationship is not absolute; performance depends on both the type of task and the time of day. A recent well-controlled study highlighted this clearly: when controlling for chronotype, raw 10 km running performance varied by up to 10% depending on the time of day, with peak performance occurring in the early evening [10]. While further research is needed to fully understand the interaction between chronotype and time of day, current evidence points to these as important factors to take into consideration..

Yet competition rarely bends to personal rhythms. Matches, games, or even important meeting times are fixed by schedules, not by competitors. Still, preparation can adapt. With evidence-based profiling, it’s possible to combine chronotype preference with actual sleep–wake behaviour to plan accordingly.

In the past, this was seen as too cumbersome, too impractical. But ignoring it comes at a cost. Sleep timing, shaped by both chronotype and current behaviour, no longer needs to be left out of the travel equation.

 

Coach the clock 

Sleep timing can be approached much like strength training or nutrition: personalised. This means aligning light exposure, darkness, sleep, naps, caffeine, and activity with an individual’s chronotype, sleep data and personal context, while keeping actual travel and performance windows at the centre of the plan. The schedule can then be adjusted if flights shift or schedules change.

 

How Phaze makes this coachable

Phaze is a circadian performance system built for teams who travel. We align the body clock to critical performance windows – at scale.

• Personal schedules for individuals (athletes, coaches, execs) based on chronotype, sleep data and personal information, direction/size of shift, performance windows, and non-negotiable team timings.
• Live oversight for performance staff to see who’s in sync, who needs help, and where schedules need adjusting.
• Adaptive by default if flights slip or kick-off moves, schedules can update.
• One system, bundled: Coaching Hub (insight + oversight) plus App (personalised guide of what to do and when). Not “another wearable” and not “just a dashboard” – a system designed for readiness.

 

Beyond sport

The same biology that shapes travel performance for athletes, pit crews, referees, and analysts on game day also applies to business travellers crossing time zones for presentations, pitches, negotiations, or reviews. Performance is universal to professionals. And if performance is time-bound, timing becomes a critical lever. In high-performance travel environments, it remains one of the least exploited advantages.

Sleep isn’t only a recovery tool – it’s a timing tool. If you wouldn’t give the same meal plan to every individual, don’t give them the same travel and sleep schedule.