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In trail running, hydration and nutrition are very important.

Failure to do either can have negative consequences on performance.

But how to hydrate well in a tropical country like Vanuatu, specially in hot season!


During a day without particular physical activity, our body needs around 2 to 3 liters of water minimum in Port-Vila (tea, coffee and of course alcohol are not included in this account!) .

If you work outside or play sports, you will need to increase this water intake even more.

Hydratation when trail running

But how to measure it? It is very simple.

Before your workout, step on the scale completely undressed. Record your weight (P1).
Then go to train (dressed of course!). Drink according to your thirst during this session, but note the quantities of water drunk (reminder: 1 liter of water = 1 kg).

As soon as you return from your session, undress and weigh yourself again (P2). You will inevitably have lost weight, water in fact!

How much ? Small calculation: P1 – P2 + water drunk = water lost through perspiration, that is to say your water needs during an effort of an equivalent duration.


I weigh 72 kg before my 1.5 hour run. During my run, I drink 500 ml of water (i.e. 500 g = 0.5 kg).
On the way back, I only weigh 69.5 kg. 72 – 69.5 + 0.5 = 3 kg of sweat lost!

Thus, in 1 hour 30 minutes of running, my water needs are 3 liters, or 1 liter per 1/2 hour of running.

If you do not take this test to assess your personal case, you must drink at least 1 liter of drink per hour of running.

What to drink

Perspiration is not just water, but mineral salts as well. This loss of mineral salts is one of the reasons for the appearance of cramps in some athletes.

Drinking only pure water will not be enough to hydrate you properly.

Your sports drink should contain sugar but also salt.

You will find sports drinks in the shops in Vila, usually expensive!

Here are 2 very simple recipes:

In your race bottles:

Recipe 1: fill half water, half fruit juice + a few pinches of table salt + juice of a lemon.

Recipe 2: fill half water, half Sprite + juice of a lemon.

Tip: test your drink during a workout to make sure your digestive system tolerates it.

Warning ! no need to binge on sugar during a race, your body can only use about 50 g per hour of effort.

When to drink

Good hydration already begins the days before the race. Make sure your urine is clear.

Before departure, prepare a slightly sweet drink and drink at least 1 liter, in several doses.

During the race, do not wait to be thirsty, it will be too late!

It is better to take small, very regular doses (every quarter of an hour) rather than drink 1 liter at once.

Warning !

The decrease in sports performance is proportional to the water loss: a loss of 2% leads to a decrease in performance of 20%! (Or for an athlete weighing 70 kg a loss of 1 liter to 1.5 liters of fluid mass).
This reduction in performance is considerably aggravated by the increase in ambient heat: a fluid loss of 4% at 18 ° C leads to a reduction in exercise capacity of 40%, which drops to 60% at 41 ° C…

Finally, we are two weeks away from the race.
It is no longer time to force yourself in training to make up for lost time or compensate for incomplete preparation.
Take stock of your abilities and do not hesitate to register at a distance less than that of your first objective.

Take part in Le Trail Pacific 2021.
It will be a great day with your family, friends, colleagues…!

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