We are made up of over 60% water and every cell in our body requires water just to function. Even the smallest degree of water loss can impair both physical and mental function. If you go for a run and at the start weigh 72.5kg and then after 20 miles weigh in at 70kg then this equates to a 4% body weight loss.
A 4% body weight loss will mean that your exercise performance will be cut by about 25% – not something you need during a long race! There is no doubt that water is essential to life, but still there are many people that don’t drink enough.
The symptoms of dehydration range from mild such as dry skin, constipation, headaches and tiredness to more severe such as low blood pressure and organ failure. If the body loses 1% of water you will start to feel thirsty, but your body is already in dehydration mode at this stage and energy and performance will be deteriorating.
Benefits of drinking more water
Drinking more water will not only help with energy, but has other benefits too. Without adequate water our immune system cannot function correctly and we are more likely to suffer colds and infections. One of the most important functions of water is to flush out toxins through our kidneys and without adequate hydration they can become clogged and not as effective. Our brains contain 15 billion cells that hold 74.5% water and this is why we often feel sluggish if dehydrated. Our mitochondria, which are the powerhouse of our cells, also need water to work effectively and supply us with energy.
How much do we need?
The old 8 glasses a day is perhaps a rather out-dated one-size fits all approach. We are all different sizes and shapes and so our requirements are different. The reality depends not only on our size, but also on our level of exercise and the weather outside. On average you lose about 1 litre of fluid for every hour of exercise.
However if you consume lots of protein then your water requirements will be greater as protein breakdown requires more water. Also if you are stressed then you need more water.
A good indicator that you are drinking enough is the colour of your urine – you are looking for a pale, straw colour – and the frequency – about 7-8 times a day is considered healthy. Coffee, tea and alcohol act as diuretics and will tend to remove more of the precious water from our body than they supply. Herbal, non-caffeinated drinks are fine.
Try not to drink too much water at meal times – this dilutes the stomach acid and makes breaking down food that much more difficult. Aim to drink most of your water between meals instead. If you haven’t been drinking enough water then start to increase your water gradually, don’t overwhelm your body with too much water too quickly.
Can I drink too much water?
Yes, over hydration (hyponatremia) although rare, is fatal as levels of sodium in the body drop too low. If you are running a race and feel lightheaded or queasy or experience dry chills, then stop the race. No personal best is worth compromising your health for.
Getting children drinking enough
It’s important to make sure your children are drinking enough water. Young children often forget to drink water and are too busy playing and having fun. They also often misread a thirsty signal as being hungry. A good practise is to fill up a large bottle of water for them every day and make sure they are drinking it all.
Flavouring it with frozen fruit such as raspberries or blueberries often encourages them to drink it. Also make sure older children are taking a bottle of water into school. Although they have access to water at school the reality is that there’s either a queue for the water fountain and they don’t want to waste precious play time or in the case of my children they complain about the water not tasting very good at school and won’t drink any unless they take their own.
Katharine Bright is a Registered Nutritional Therapist with a clinic in Sevenoaks. To book an appointment call her on 07769 636352 or email firstname.lastname@example.org. She is co-founder of The Health Boost (www.thehealthboost.co.uk) – a website dedicated to providing a family friendly solution to healthy eating.