From baking in the sun on holiday to sitting at a desk all day without taking a break, modern life offers up plenty of opportunities to forget to drink enough water.

Antje Gahl, a spokeswoman for the German Nutrition Society, explains how we can make sure we stay hydrated.

Can I stay hydrated by drinking water in advance?

No. People have no reservoir of water.

If we drink more liquid than our body needs, it will simply be excreted through the kidneys.

Still, it is wise to heed feelings of thirst. They are a reliable sign from the body to protect us from dehydration.

How often should I drink water?

The Mayo Clinic recently has found that, depending on certain conditions, men need about 3 litres of water a day while women should have 2.2 litres.

Gahl says, “Under certain conditions, such as very warm, damp or extremely cold weather, or when the person is suffering from an illness that is causing fever, vomiting or diarrhoea, we need more liquid. The same happens when we do demanding physical work or sport, which can require an additional 0.5-1 litres of water per hour”.

Depending on different conditions, such as sports, weather and so on, your water needs may be different.

Can I wait until I get thirsty?

Feeling thirsty is a clear warning sign indicating a fluid deficiency, which means that we should always try to drink regularly before it happens.

Elderly people in particular tend not to feel thirsty, which increases the risk that they may not be drinking enough.

If you do not feel thirsty very often, you should be particularly careful to make sure you are drinking enough -at least 1 litre per day.