POSITION STATEMENT
Coping with jet-lag: A Position Statement for the European College of
Sport Science
THOMAS REILLY
1
, GREG ATKINSON
1
, BEN EDWARDS
1
, JIM WATERHOUSE
1
,
TORBJO
¨ RN A˚KERSTEDT
2
, DAMIEN DAVENNE
3
, BJO
¨ RN LEMMER
4
, &
ANNA WIRZ-JUSTICE
5
1
Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK,
2
Department of Public
Health Sciences, Karolinska Institute, Stockholm, Sweden,
3
Centre de Recherches en Activite´s Physiques et Sportives,
University of Caen, Caen, France,
4
Institute of Pharmacology and Toxicology, Ruprecht-Karls-Universiteit Heidelberg,
Heidelberg, Germany, and
5
Centre for Chronobiology, Psychiatric University Clinics, Basel, Switzerland
Abstract
Elite athletes and their coaches are accustomed to international travel for purposes of training or sports competition.
Recreational participants are similarly, if less frequently, exposed to travel stress. Transient negative effects that constitute
travel fatigue are quickly overcome, whereas longer-lasting difficulties are associated with crossing multiple time-zones.
Jet-lag is linked with desynchronization of circadian rhythms, and its impact depends on the duration and direction of flight,
flight schedule, and individual differences. Athletes’ performances are likely to be affected for some days until the body clock
is readjusted in harmony with local time. Knowledge of the physiological characteristics of the body clock can be used to
develop behavioural strategies that accelerate readjustment, in particular the timing of outdoor or bright light exposure,
perhaps melatonin ingestion, meals, and exercise. Attempts to promote sleep by use of drugs that adjust the body clock,
induce sleepiness or promote wakefulness are relevant but discouraged in travelling athletes. Support staff should develop
appropriate education programmes for their athletes who can then make informed choices about their behaviour and
minimize the transient effects of jet-lag on their well-being and performance.
Keywords: Chronobiology, circadian rhythms, fatigue, sleep, travel
Introduction
Contemporary elite athletes are frequent travellers
across multiple time-zones. These journeys are
undertaken to participate in club or international
competition in single engagements or for more
prolonged sojourns when tournaments are involved.
In other instances, groups of athletes or members of
sports teams take advantage of altitude or seasonal
differences in weather conditions to attend training
camps in other parts of the world where the climate
is more conducive to strenuous exercise. Professional
athletes based in Europe, such as soccer players, may
incur a competitive schedule that includes interna-
tional representation for their country on another
continent (Asia, America or Australia) in between
important domestic contests for the club. Such
itineraries place a physiological and psychological
burden on those athletes who have to adjust to a
different time-zone and a different climate and then
have to re-adjust back to their home time-zone after
the return journey.
Irrespective of the mode of transport, travelling
can cause discomfort and fatigue. The passenger
may become stiff as a result of being in a cramped
posture for too long during an air flight or a journey
by car or omnibus. There may be stresses associated
with the journey, delays, unplanned stops or detours.
With flights there are also the problems caused by
hypoxia. The fatigue and dehydration that result are
transitory and can be remedied on arrival by
rehydration, a rest or light exercise, and a shower
or bath. This form of tiredness or ‘‘travel fatigue’’
Correspondence: T. Reilly, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, 15
Á21 Webster Street,
Liverpool L3 2ET, UK. E-mail: t.p.reilly@ljmu.ac.uk
European Journal of Sport Science, March 2007; 7(1): 1
Á7
ISSN 1746-1391 print/ISSN 1536-7290 online # 2007 European College of Sport Science
DOI: 10.1080/17461390701216823
(see Table I) is experienced when flying directly
northwards or southwards, for example from main-
land Europe to South Africa or from Canada to
South America.
Travel fatigue accompanies any long journey, but
a unique syndrome known as jet-lag is induced when
long-haul flights entail crossing multiple meridians.
Symptoms (see Table II) are due to a mismatch
between ‘‘body clock time’’ and the new local time.
The body clock gradually adapts to local time in the
new environment and when this process is complete
the symptoms of jet-lag disappear (Lemmer, Kern,
Nold, & Lohrer, 2002; Reilly, Atkinson, & Water-
house, 1997). Since jet-lag can have a negative
influence on exercise performance (Waterhouse,
Reilly, & Atkinson, 1997), and on the mood and
performance of accompanying support personnel
(Waterhouse et al., 2002a; Waterhouse, Minors,
Waterhouse, Reilly, & Atkinson, 2002b), the provi-
sion of travel guidelines to sports participants is
worthwhile.
In these guidelines, we first explain the nature of
circadian rhythms that are controlled by the body
clock. This outline is necessary for an understanding
of the behaviour of the body clock when rhythms are
desynchronized, which occurs in nocturnal shift-
work as well as time-zone transitions. Methods
commonly promoted for alleviating jet-lag and
hastening adjustment to the new time-zone are
considered and evaluated. Strategies designed to
help deal with itineraries depend on the direction
of flight, times of departure and arrival, and mission
objectives. Advice can also be given regarding sleep
loss. These strategies need to be translated into
compact recommendations to be of practical benefit
to athletes and their medical and scientific mentors.
The body clock
The body clock is located within the suprachiasmatic
nuclei (SCN) of the hypothalamus. The retino-
hypothalamic tract and the intergeniculate leaflet
provide input pathways from the retina (photic
signals) and other regions of the brain (non-photic)
to the timekeeping cells of the SCN. These act as
‘‘Zeitgebers’’ or synchronizing agents for the endo-
genous rhythmicity that is usually somewhat longer
than 24 h. A multi-synaptic pathway from the SCN
leads to the pineal gland, where melatonin is
secreted at night and suppressed by light.
Natural light is the predominant Zeitgeber for the
body clock, though less bright, artificial light also
exerts an effect. This means that light in the morning
can advance circadian rhythms to earlier, and light in
the evening can delay circadian rhythms to later.
This concept, that of a ‘‘phase-response curve’’,
provides the practical basis for timing light exposure
to attain more rapid shifts across time zones going
east (advance) or west (delay). Melatonin receptors
are found on the SCN, which means that exogenous
melatonin can also act as a Zeitgeber to shift the
biological clock. The phase-response curve to mel-
atonin is opposite to that for light: melatonin in
the evening can advance circadian rhythms to ear-
lier, whereas melatonin in the morning can delay
circadian rhythms to later (Cajochen, Kra¨uchi, &
Wirz-Justice, 2003). Additionally, melatonin has
direct effects on thermoregulation, which may be
the mechanism by which it induces sleepiness
(Atkinson et al., 2003; Kra¨uchi, Cajochen, & Wirz-
Justice, 2005). Vasodilation in the hands and feet
occurs rapidly after melatonin ingestion during the
day, or at the natural time of melatonin secretion
onset in the evening, and warm hands and feet are
the physiological ‘‘gate’’ promoting sleep onset.
Conversely, the direct effects of light to inhibit
melatonin secretion also lead to distal vasonconstric-
tion, with a concomitant increase in alertness
(Kra¨uchi et al., 2005). Light also promotes wakeful-
Table I. Checklist for travel fatigue (based on Waterhouse et al.,
2002b).
Symptoms
Fatigue
Disorientation
Headaches
‘‘Travel weariness’’
Causes
Disruption of normal routine
Hassles associated with travel (checking in, baggage claim,
customs clearance)
Dehydration due to dry cabin air
Advice
Before the journey
Plan the journey well in advance
Try to arrange for any stopover to be comfortable
Be clear about documentation, inoculations, visas, etc.
Make arrangements for activity at your destination
During the flight
Take some roughage (e.g. apples) to eat
Drink plenty of water or fruit juice; avoid tea, coffee, and
alcohol
On reaching your destination
Relax with a non-alcoholic drink
Take a shower
Take a brief nap, if feeling exhausted
Table II. Symptoms of jet-lag (based on Waterhouse et al., 1997).
.
Feeling tired in the new local daytime, and yet unable
to sleep at night
.
Waking in the new night, and unable to get back to sleep
.
Feeling less able to concentrate or to motivate oneself
.
Decreased mental and physical performance
.
Increased incidence of headaches and irritability
.
Loss of appetite and general bowel irregularities
2
T. Reilly et al.
ness, not only through this mechanism but also
directly through the sympathetic nervous system.
Circadian rhythms and the sleep
Á
wake cycle
While the rhythm of core body temperature is
regarded as a good marker of the circadian system,
many other physiological functions exhibit such 24-h
cycles. However, in addition to the body clock, many
measures are also affected by the duration of prior
time awake. This phenomenon is called the ‘‘sleep
homeostat’’, and it is the interactions between the
two processes that are important for behaviour.
Performance measures tend to follow closely the
rhythm in core body temperature.
Drust and colleagues (Drust, Waterhouse, Atkin-
son, Edwards, & Reilly, 2005) pointed out that many
indices of sports performance had both a 24-h
component (which would be parallel to the rhythm
in core temperature) in addition to a component
synchronous with the sleep
Áwake cycle. These two
components are desynchronized after travelling
across multiple time-zones, so that a deterioration
in exercise and any other performance is likely to
accompany this disruption of the body clock with
respect to sleep timing. Besides, the symptoms of jet-
lag (particularly those due to loss of sleep) are likely
to have a de-motivating effect that will in turn impair
performance.
Factors affecting jet-lag
The severity of jet-lag depends on the number of
time-zones crossed and on the direction of travel.
Symptoms are felt more acutely after travelling
eastwards than after travelling westwards due to
the greater ease of effecting a phase delay (i.e. to
follow the longer-than-24-h endogenous rhythmicity
of the body clock by drifting later). Allowing one day
for each time-zone crossed for travellers to adjust
seems to accommodate most people irrespective
of the direction of travel (Waterhouse, Reilly, &
Edwards, 2004), in particular where strategies to
accelerate the readjustment are respected.
Although there are differences between individuals
in their sensitivity to jet-lag, these differences appear
to be small. Physical fitness may be beneficial, due
either to its sleep-promoting effects or its association
with mental toughness to cope with subjective
discomfort. Younger individuals (notably athletes)
may have a capability to cope better with circadian
desynchronization, while older travellers (notably
support personnel) derive benefit from experience
of previous trips. Surprisingly, the young experience
greater sleepiness and performance deficits with
sleep deprivation than the old
Á who are already
slower during the day (Blatter et al., 2006). Habitual
female travellers may experience secondary amenor-
rhoea but the lifestyle of female athletes entails
frequent but not habitual travelling. Morning-
type individuals would have a theoretical advantage
in
adjusting
to eastward
travel, and evening-
types to a westward flight, but the majority of
athletes are intermediate in chronotype (Waterhouse
et al., 2004).
For time-zone transitions approaching 12 h (to-
wards the antipodes), there is some evidence that
splitting the journey into 2 days with an overnight
stopover can lessen the subjective symptoms experi-
enced (Reilly & Waterhouse, 2005). Such stopovers
may not be feasible in the case of sports groups for
logistic and financial reasons, or because of losing
training opportunities. While travel strategies can be
designed to deal with itineraries that are imposed on
the athletes concerned, it is preferable to have a
choice of departure and arrival times, and alternative
carriers. Coping strategies are easier to implement
Table III. Recommendations for the use of bright light to adjust
the body clock after time-zone transitions (from Reilly et al.,
2005).
Bad local times for
exposure to light
Good local times for
exposure to light
Local time
Local time
Time zones to the west (h)
3
02:00
Á08:00
a
18:00
Á24:00
b
4
01:00
Á07:00
a
17:00
Á23:00
b
5
24:00
Á06:00
a
16:00
Á22:00
b
6
23:00
Á05:00
a
15:00
Á21:00
b
7
22:00
Á04:00
a
14:00
Á20:00
b
8
21:00
Á03:00
a
13:00
Á19:00
b
9
20:00
Á02:00
a
12:00
Á18:00
b
10
19:00
Á01:00
a
11:00
Á17:00
b
11
18:00
Á00:00
a
10:00
Á16:00
b
12
17:00
Á23:00
a
09:00
Á15:00
b
13
16:00
Á22:00
a
08:00
Á14:00
b
14
15:00
Á21:00
a
07:00
Á13:00
b
15
14:00
Á20:00
a
06:00
Á12:00
b
16
13:00
Á19:00
a
05:00
Á11:00
b
Time zones to the east (h)
3
24:00
Á06:00
b
08:00
Á14:00
a
4
01:00
Á07:00
b
09:00
Á15:00
a
5
02:00
Á08:00
b
10:00
Á16:00
a
6
03:00
Á09:00
b
11:00
Á17:00
a
7
04:00
Á10:00
b
12:00
Á18:00
a
8
05:00
Á11:00
b
13:00
Á19:00
a
9
06:00
Á12:00
b
14:00
Á20:00
a
10
Can be treated as 14 h
to the west
c
11
Can be treated as 13 h
to the west
c
12
Can be treated as 12 h
to the west
c
a
Denotes promotion of a phase advance.
b
Denotes a delay of the body clock.
c
Reflects that the body clock adjusts to large delays more easily
than to large advances.
Coping with jet-lag: A Position Statement
3
when arrival times at destination are in the late
afternoon or evening (Waterhouse et al., 2002a). In
these cases, individuals have the opportunity to take
a full sleep at night in the new time-zone sooner after
arrival. Cultural differences in the country of desti-
nation do not affect jet-lag but the climate encoun-
tered may do so. A high environmental temperature
can accentuate the dehydration following a long-haul
flight due to the dry cabin air, and hypoxia at altitude
could compound subjective discomfort for athletes
travelling across time-zones to training venues at
altitude.
Dealing with jet-lag
The trip should be planned so as to arrive a number
of days before the competition. This period will vary
in accordance with the number of time-zone transi-
tions experienced. Strategies for minimizing the
effects of jet-lag embrace activities pre-flight, while
on board the aircraft, and following arrival in the
new destination. Pre-flight factors include planning
details of the journey and adjustment of the sleep
Á
wake cycle in accordance with the direction of flight.
Adjustment of more than 2 h in retiring to bed is
counterproductive since this change is liable to cause
rhythm disturbance and impair the quality of train-
ing undertaken before departure (Reilly & Maskell,
1989). Planning the trip can include the times
during flight when sleep is attempted (see below)
and what meals are taken and/or missed.
It has been suggested that once the aircraft is
boarded, the travellers should set their watches and
begin to live (eat and sleep) in agreement with the
local time at destination (Waterhouse et al., 2004).
The dry air on board the aircraft can cause a gradual
dehydration that is not perceived by the body.
Passengers are therefore advised to drink more
than expected to counteract this added fluid loss.
Water and fruit juices are recommended, and
diuretics such as alcohol and caffeine discouraged.
Periodically getting up to walk in the aisles, or do
light stretching exercises, will alleviate joint stiffness
and safeguard against deep vein thrombosis (House
of Lords Select Committee, 2000). Compression
stockings also have a protective effect against deep
vein thrombosis. Sleep and naps during the journey
should be attempted only if it is night at the final
destination; if this is not the case, then conversation
or investigating the in-flight entertainment is ad-
vised. Sleep may be assisted by wearing eye-shades
and ear plugs and wearing loose-fitting clothing.
The more appropriate behaviour on arrival at
destination will depend on the direction of flight,
the number of time-zones crossed, and the time of
arrival. Separate strategies can be devised for east-
ward and westward travel. Generic therapies such as
massage may have transient value in reversing the
effects of having been sitting in a cramped position
but have no direct impact on the body clock.
Similarly, there is little evidence for feeding pro-
grammes that promote protein intake in the morning
and mainly carbohydrate in the evening to hasten
adjustment to the new time; the timing of the meal to
fit in with habitual routines in the new environment
is more likely to help readjustment of the body
clock than is the macronutrient content (Reilly &
Waterhouse, 2005). However, carbohydrates in the
morning appear to advance circadian rhythms com-
pared with carbohydrates in the evening meal
(Kra¨uchi, Cajochen, Werth, & Wirz-Justica 2002),
so more research on this theme of food as Zeitgeber
is required. Adequate fluid ingestion is recom-
mended and caffeine can help in combating sleep-
iness when experienced during the day. Although
this arousal effect of caffeine is beneficial during the
day while the body clock is being readjusted, there
can be unwanted effects of evening ingestion on
recovery sleep (Beaumont et al., 2004). Exercise,
especially outdoors if it is a sunny day, can also have
a positive effect on arousal, but morning exercise
should be avoided for a few days after an eastward
flight when it could induce a counter-productive
phase-delay response (Edwards, Waterhouse, Atkin-
son, & Reilly, 2002). In any case, exercise training
should be taken at the time of day of the future
competition, the sooner after the flight the better.
During the first training sessions, maximal exercise
and risky manoeuvres should be avoided to prevent
injuries. Exercising outdoors also helps the body to
adjust to the new environment (especially when
temperature and humidity are high).
Although benzodiazepines and non-benzodiaze-
pine soporifics have been advocated for inducing
sleep, and some benzodiazepines may act as chron-
obiotics (change the phase of the body clock), their
benefits are not universally confirmed. Jet-lag re-
ported by British Olympic athletes after a 5-h time-
zone transition westward was unaffected by ingestion
of temazepam (Reilly, Atkinson, & Budgett, 2001).
A similar ineffective treatment using zopiclone was
reported for a French group making a westward trip
of the same phase-shift to Martinique (Daurat,
Benoit, & Buguet, 2000). Moreover, these drugs
have myorelaxant effects that can last longer than the
hypnotic effects and might be dangerous when
exercising.
Melatonin is a special case. Its vasodilatory effects
do promote sleep without having any marked effects
on the sleep EEG (in contrast to benzodiazepines)
(Cajochen et al., 2003). However, the purity of
melatonin bought ‘‘off-the-shelf ’’ and without pre-
scription (where available) cannot be guaranteed.
It can also have unwanted side-effects in some
4
T. Reilly et al.
individuals (Reilly, Maughan, & Budgett, 1998).
The position is complicated in so far as melatonin,
and possibly some benzodiazepines, can act as
chronobiotics. While such an adjustment using
melatonin could be beneficial, it must be in the
required direction (a phase advance or delay follow-
ing a flight to the east or west, respectively).
For any chronobiotic drug, the direction in which
the body clock is shifted depends on the time of
ingestion. In practice, ingestion is normally in the
evening in the new time-zone (to promote sleep), so
this is appropriate for adjusting the body clock only
after some flights. Experimental data as to a phase-
shifting role in field conditions are lacking. In other
words, the chronobiotic
Á as opposed to the sopori-
fic
Á value of these substances is unclear.
Athletes must be protected against the ingestion of
drugs on the banned list of the International
Olympic Committee and sports governing bodies.
Hence, drugs such as modafinil, methylphenidate,
and pemoline that are viable antidotes to fatigue in a
civilian or military context have no place in treating
the effects of sleep loss due to jet-lag.
Bright light also can adjust the body clock and it
opposes the action of melatonin. Therefore, seeking
exposure to natural daylight and avoiding bright light
at the appropriate times is important in determining
the rate of readjustment to the new time-zone. Again
the timing of such behaviours is crucial and the
phase-response curve to light should therefore be
taken into consideration. Guidelines for the best and
worst time for exposure to light are shown in Table II
according to the direction of travel and the number
of time-zones crossed. The availability of artificial
indoor lighting should also be considered where
these guidelines are being implemented; sitting
near a window amounts to exposure to bright light,
whereas sitting in a dimly lit room away from
windows amounts to avoiding bright light.
Recommendations
The following recommendations are based on ob-
servations on elite athletes and other travellers
(Reilly, Waterhouse, & Edwards, 2005; Waterhouse
et al., 1997, 2002a). While travel strategies are best
designed for specific journeys and activity schedules,
general principles can be applied based on the
direction of flight and the number of meridians
crossed. A checklist for planning purposes was
presented by Waterhouse et al. (2004) and is
updated in Table I. Adherence to such forward
planning should ensure that the individual arrives
in good time at the point of departure, rested, and
free of anxieties about the trip.
During the flight
Travellers are encouraged to prepare for their own
comfort, as far as possible, in advance of boarding
the flight. Tall persons flying economy class might
enquire at check-in on the most suitable seats
available for them. For all passengers, wearing
appropriate loose-fitting clothing should contribute
to comfort on board. Relaxation can be planned for
the hours between meals and, depending on the
timing of the flight, some meals can be missed.
Emphasis needs to be placed on fluid intake,
avoiding diuretics such as coffee and alcohol.
‘‘Travellers’ thrombosis’’ is now recognized as a
risk when individuals are in a cramped position
without activity for a prolonged period. Periodic
activity, approximately every 2 h, can include iso-
metric exercises, walks along the aisles or stretching
exercises. Compression stockings have been advo-
cated for preventive purposes. Drugs such as aspirin
have anti-thrombotic properties but are not univer-
sally prescribed due to the possibility of side-effects
in some individuals.
After travelling westwards
On long-haul flights westward, a short nap may be of
benefit. The theoretical value of this short sleep is
that it reduces the homeostatic drive towards sleepi-
ness that initially occurs with an extended first day of
travel.
A flight westwards requires a phase delay of the
body clock. It is important to remain active during
the daytime and avoid long naps. Napping can
contrive to anchor the body clock to the time-
zone departed and have a counterproductive effect
(Minors & Waterhouse, 1981). Light exercise can
have a positive benefit, help to maintain arousal, and
offer transient relief of jet-lag symptoms (Edwards
et al., 2002). Social activity and fitting in with local
time can facilitate exposure to Zeitgebers, particu-
larly the light
Ádark cycle, supporting the readjust-
ment of the body clock and the restoration of normal
circadian rhythms.
It is acceptable to retire to bed 1
Á2 h earlier than
normal according to local time. Conversely, waking
up may occur earlier than normal in the new time-
zone. The changes in sleep
Áwake cycles are transient
and normal sleeping patterns tend to be restored
before
the rhythm in internal body tempera-
ture returns to its normal circadian phase (Reilly
et al., 2001).
After travelling eastwards
When travelling through the night, a period of quiet
is scheduled by airlines to allow possibilities for
Coping with jet-lag: A Position Statement
5
sleep. Typically, flights eastwards from Europe to
Asia and Australia are overnight. The most likely
times for sleep coincide with night in the time-zone
just left, but the most appropriate time is during
darkness in the time-zone at destination. On long-
haul flights eastward that total 20
Á22 h, travelling
athletes tend to obtain about 4 h sleep in total
(Waterhouse et al., 2004). Although the duration of
sleep during flight is not correlated with jet-lag
symptoms subsequently experienced, it does have a
recuperative value (the homeostatic component) and
possibly begins the process of adjustment to the new
time-zone.
Adherence to the phase-response curve to light is a
key to resynchronizing circadian rhythms after flying
eastwards. In this instance, a phase-advance of the
body clock is required. The strategy therefore is to
exploit the positive effects of natural light, but only
after the trough of the body temperature is reached.
The problem arising after crossing many time-zones
(e.g. 6
Á9 h) to the east is that a morning arrival may
coincide with body clock time that precedes this
trough. In such instances, use of light shades in the
plane and dark glasses en route to the immediate
accommodation can minimize light exposure and
allow the traveller to retire to bed until late morning
if necessary after arriving, having hurried to the new
accommodation to do so. As Table II indicates, light
exposure in the new afternoon is beneficial.
Based on the same chronobiological principle,
morning
training
should
be
avoided
for
the
first few days under these circumstances. In con-
trast, exercise in the late afternoon would be
beneficial.
In flights eastwards over nine or more time-zones,
it is possible that the body clock adjusts by means of
a phase delay rather than a phase advance (Water-
house et al., 2002a). This is more likely if there is
exposure to bright light in the morning and/or the
traveller is ingesting melatonin in the evenings before
bedtime. For such eventualities, a behavioural and
concerted light exposure/avoidance strategy can be
implemented (see Table II). It must be realized that,
on the day of arrival, minimum temperature and
performance will be in the late afternoon (about
05:00 h by time in the departure zone). Adjusting
the body clock by phase advance will cause this nadir
to advance through the afternoon and morning. In
contrast, if the body clock adjusts by delaying, then
the nadir soon moves to the later afternoon and
evening. These differences due to the direction of
adjustment have implications for training and pre-
paration for matches. They should be borne in mind
when considering the timing of the scheduled
competitive engagements.
Overview
These guidelines are designed to help travelling
athletes and any accompanying support staff to
adjust quickly to new locations after long-haul
flights. They are based on chronobiological princi-
ples and an understanding of how the body clock
operates. Knowledge of the underlying physiology
provides an insight into the impact of travel on
circadian rhythms, well-being, and exercise perfor-
mance. To ensure quality of performance, travel
strategies must be actively managed and sports
organizations should recognize the likely negative
effects of jet-lag on the performance of athletes. An
effective education programme would enable travel-
ling athletes to make informed choices about their
travel plans and adopt appropriate behaviours to
minimize discomfort. Modification of behaviour to
suit the progressive adjustment to the new time-zone
is preferred to using chronobiotic or soporific drugs.
Since there is no physiological adaptation on repe-
titive time-zone transitions, each long-haul journey is
unique and requires its own specific travel strategy,
based on direction of travel, duration, and times of
embarkation and disembarkation. Most important of
all for competitive sport, is to allow a sufficient
number of days in the new time zone to attain re-
entrainment and thus facilitate peak performance.
References
Atkinson, G., Drust, B., Reilly, T., & Waterhouse, J. (2003). The
relevance of melatonin to sports medicine and science. Sports
Medicine , 33 , 809
Á831.
Beaumont, M., Bate´jat, D., Pie´rard, C., Van Beers, P., Denis,
J. B., Coste, O., et al. (2004). Caffeine or melatonin effects on
sleep and sleepiness after rapid eastward transmeridian travel.
Journal of Applied Physiology, 96 , 50
Á58.
Blatter, K., Graw, P., Mu
¨ nch, M., Knoblauch, V., Wirz-Justice,
A., & Cajochen, C. (2006). Gender and age differences in
psychomotor vigilance under differential sleep pressure condi-
tions. Behavioural Brain Research , 168 , 312
Á317.
Cajochen, C., Kra¨uchi, K., & Wirz-Justice, A. (2003). Role of
melatonin in the regulation of human circadian rhythms and
sleep. Journal of Neuroendocrinology, 15 , 432
Á437.
Daurat, A., Benoit, O., & Buguet, A. (2000). Effects of zopiclone
on the rest/activity rhythm after a westward flight across five
time zones. Psychopharmacolgy (Berlin) , 149 , 241
Á245.
Drust, B., Waterhouse, J., Atkinson, G., Edwards, B., & Reilly, T.
(2005). Circadian rhythms in sports performance: An update.
Chronobiology International , 22 , 21
Á44.
Edwards, B., Waterhouse, J., Atkinson, G., & Reilly, T. (2002).
Exercise does not necessarily influence the phase of the
circadian rhythm in temperature in healthy humans. Journal
of Sports Sciences , 20 , 725
Á732.
House of Lords Select Committee on Science and Technology
(2000). Air travel and health . London: The Stationery Office.
Kra¨uchi, K., Cajochen, C., Werth, E., & Wirz-Justice, A. (2002).
Alteration of internal circadian phase relationships after timed
CHO-rich meals in humans. Journal of Biological Rhythms , 17 ,
364
Á376.
6
T. Reilly et al.
Kra¨uchi, K., Cajochen, C., & Wirz-Justice, A. (2005). Thermo-
physiologic aspects of the three-process-model of sleepiness
regulation. Clinics in Sports Medicine , 24 , 287
Á300.
Lemmer, B., Kern, R.I., Nold, G., & Lohrer, H. (2002). Jet lag in
athletes after eastward and westward time-zone transition.
Chronobiology International , 19 , 743
Á764.
Minors, D., & Waterhouse, J. (1981). Anchor sleep as a
synchronizer of rhythms in abnormal routines. International
Journal of Chronobiology, 7 , 165
Á188.
Reilly, T., Atkinson, G., & Budgett, R. (2001). Effect of low-dose
temazepam on physiological variables and performance follow-
ing a westerly flight across five time zones. International Journal
of Sports Medicine , 22 , 166
Á174.
Reilly, T., Atkinson, G., & Waterhouse, J. (1997). Biological
rhythms and exercise . Oxford: Oxford University Press.
Reilly, T., & Maskell, P. (1989). Effects of altering the sleep
Áwake
cycle in human circadian rhythms and motor performance.
In Proceedings of the First IOC World Congress on Sport Science
(p. 106). Colorado Springs, CO: US Olympic Committee.
Reilly, T., Maughan, R., & Budgett, R. (1998). Melatonin: A
Position Statement of the British Olympic Association. British
Journal of Sports Medicine , 32 , 99
Á100.
Reilly, T., & Waterhouse, J. (2005). Sport, exercise and environ-
mental physiology. Edinburgh: Elsevier.
Reilly, T., Waterhouse, J., & Edwards, B. (2005). Jet lag and air
travel: Implications for performance. Clinics in Sports Medicine ,
24 , 367
Á380.
Waterhouse, J., Edwards, B., Nevill, A., Carvalho, S., Atkinson,
G., Buckley, P., et al. (2002a). Identifying some determinants
of ‘jet lag’ and its symptoms: A study of athletes and other
travellers. British Journal of Sports Medicine , 36 , 54
Á60.
Waterhouse, J., Minors, D., Waterhouse, M., Reilly, T., &
Atkinson, G. (2002b). Keeping in time with your body clock .
Oxford: Oxford University Press.
Waterhouse, J., Reilly, T., & Atkisnon, G. (1997). Jet-lag. Lancet ,
350 , 1611
Á1615.
Waterhouse, J., Reilly, T., & Edwards, B. (2004). The stress of
travel. Journal of Sports Sciences , 22 , 946
Á966.
Coping with jet-lag: A Position Statement
7
Dostları ilə paylaş: |