content may be followed by a feeling of drowsi-
ness. Thus, what and when an athlete eats may
influence the severity and duration of jet-lag
symptoms, and it has been suggested that high-
protein foods should be eaten at breakfast time
and high-carbohydrate meals taken at night
(Reillyet al. 1997b). Central nervous system
stimulants, such as the caffeine in tea and coffee,
may be beneficial when taken in the mornings
on arrival at the new destination, but are best
avoided in the later part of the day. Drinking an
adequate amount of fluids is also recommended,
as dehydration can aggravate the symptoms of
fatigue and jet lag. This implies a need for care in
the use of caffeine-containing beverages and
alcohol because of the possible diuretic effects.
Where a single major event involving long-
distance travel is scheduled, there may be advan-
tages for some individuals in preparing before
departure. If this is to be attempted, it might be
suggested that, 3 days before travel, athletes
should begin training, sleeping, eating and
drinking according to the time of their destina-
tion. It should be recognized, however, that
attempts at preadjustment by changes in lifestyle
have generally been found to be ineffective
because of the difficulty in controlling all the
factors involved.
In recent years, melatonin has been used by
some athletes to avoid jet lag (Grafius 1996).
Melatonin is a hormone derived from the pineal
gland that affects the body’s sleep–wake cycle.
Research has shown that low doses of melatonin
taken in the evening can help induce sleep
(Zhdanovaet al. 1995). Oral doses of melatonin
(0.5–3 mg) taken 1 h before bedtime appears to be
safe and effective (Grafius 1996). However, as
with any substance, melatonin may be tolerated
differently by each athlete. Morning grogginess
and vivid dreams have been reported with use
of melatonin. For the athlete who wants to try
melatonin, experimenting with it prior to travel
or competition is recommended. Melatonin is
not included on the list of prohibited substances.
The purity of commercial preparations is uncer-
tain, and melatonin content of some preparations
may be less than the stated dose.
488 practical issues
Traveller’s diarrhoea and
other infections
Once an athlete arrives in a new country, one of
the greatest fears is becoming ill just prior to
or during competition. Although there is little
recent information, one report suggests that
up to 60% of athletes travelling abroad may be
affected by some form of gastroenteritis
(Grantham 1983). Food-borne illnesses and
gastrointestinal distresses of other aetiology can
prohibit participation or diminish performance.
Traveller’s diarrhoea is a concern to athletes irre-
spective of the country of origin or destination.
Traveller’s diarrhoea can be caused by food or
water that contains bacteria, viruses or parasites.
It is estimated that bacterial enteropathogens
cause at least 80% of traveller’s diarrhoea with
Escherichia coliandShigellabeing the two most
common agents (DuPont & Ericsson 1993).
Clinical features of traveller’s diarrhoea include
frequent loose stools and abdominal cramps,
sometimes accompanied by nausea, vomiting or
the passage of bloody stools. Since contaminated
food and water can cause traveller’s diarrhoea,
athletes need to be cautious of what they eat
and drink and to apply stringent food hygiene
rules. Prevention of the problem involves
selecting eating establishments that are well
known or recommended by coaches or other
individuals who have been to the area before and
who are aware of the food safety issues. Contact-
ing your country’s embassy in the country of
your destination to identify in advance potential
problems can also be of value. Information on
immunization requirements and recommended
prophylactic precautions should also be estab-
lished well in advance of travel, and this advice is
readily available from travel agents, airlines and
embassies.
Foods such as fruits that can be peeled and
vegetables that have been thoroughly washed
with boiling water are generally safe food
choices. For the most part, athletes should drink
only bottled water, juices or soft drinks from
sealed containers. The following list provides
guidance for foods and beverages generally con-