The Hidden Danger of Dehydration – Don’t Let it Ruin Your Ride!

With the UK in the midst of a heatwave / warm summer where temperatures are reaching the very high twenties and low thirties, we thought this would be the perfect opportunity to help bikers make the most of it. Many will head off at a moment’s notice when the sun comes out, and why not? You’ve got to make hay while the sun shines. Especially in the usually wet-windy-rainy UK.

While that’s true, it’s also important to remember that the sun and heat can be a danger. As much as we all might like to jump on our bikes and dart off to the coast and dip our toes in the sea, it’s important to realise the risks we might be taking if we don’t keep ourselves properly hydrated before, during and after our ride. Some recent research has found that driving while dehydrated has the same effect as drink driving.

Dr Phil Watson – Free University, Brussels – says “The research has shown us the impact dehydration can have on our ability to control a vehicle, whether that’s a car, lorry or motorbike. It revealed the number of mistakes we make doubles when we’re dehydrated, the same margin of error as people who are at the drink driving limit – 0.08% blood-alcohol in England, Wales and Northern Ireland.”

Jane Holdsworth, Director of the European Hydration Institute (EHI), adds “Anecdotal evidence suggests that many drivers avoid drinking on long journeys to minimise bathroom stops, yet we know that even mild dehydration can cause symptoms such as headache, tiredness and lethargy.”

Darting out on a whim when the sun comes out might seem spontaneous and exciting, but riding while dehydrated is going to diminish your ability to control your bike and stay safe.

What is dehydration?

We become dehydrated when our bodies lose more water than they take in. This disrupts the balance of minerals (sugars and salts) in our bodies and affects how we function. Any reduction in our physical or mental capacity will naturally affect how well we’re able to ride and increase the chance of making a mistake or losing control.

Dehydration comes in three forms: mild, moderate and severe. The risk of accidents aside, avoiding and tackling any form of dehydration is always important because, if untreated, it can lead to much more serious and dangerous conditions like heat exhaustion and heatstroke.

Common signs of mild or moderate dehydration include:

  1. Thirst
  2. Dry mouth, lips and eyes
  3. Dark urine or strong smelling urine
  4. Passing urine less than three or four times a day
  5. Headaches, dizziness
  6. Lack of energy
  7. Feeling lightheaded
  8. Loss of strength and stamina

These symptoms can easily be reversed by taking fluids and resting in a cool, shaded place as soon as you become aware of them.

Severe dehydration – an emergency condition that needs immediate hospital treatment – can have these additional symptoms:

  1. Feeling unusually tired or confused, especially when you think you’re dehydrated
  2. Dizziness when you stand up that doesn’t go away after a few seconds
  3. Not passing urine for eight hours
  4. A weak pulse
  5. A rapid pulse
  6. Fits (seizures)
  7. A low level of consciousness

Related conditions

Dehydration is a main cause of heat exhaustion and can also lead to heatstroke.

Heat exhaustion results in a drop in blood pressure caused by being exposed to heat for too long. You might feel sick, faint and sweat heavily. This needs to be treated quickly by moving to a cool, shaded area and drinking more water and removing excess clothing. You should feel better in half an hour but if you don’t treat it early on it can lead to heatstroke – a very dangerous condition.

Heatstroke is also caused by overexposure to heat and results in the body’s core temperature rising to dangerous levels. If that happens, you’ll need to be treated immediately at hospital.

How to avoid and tackle dehydration

Drinking plenty of water regularly throughout the day is the best way to avoid dehydration because it contains no sugar or salts which can exacerbate dehydration or cause other complications. After water, natural fruit juices and organic smoothies are the next best choice. Always read the label so you understand how much sugar and salt are in the drink, and try to avoid drinks with lots of sugar or caffeine because these can lead to other health problems.

It goes without saying, not riding during the hottest part of the day is an easy way to avoid dehydration too. When exactly that time is can vary according to the weather conditions on any given day and the country you’re riding in.

Planning your route and stops, and taking water with you will definitely help you make the most of the summer. You’ll be able to regulate your food and water intake, use a proper toilet, and enjoy your ride without worrying about how dehydration could ruin your chances of a nice day out.

NHS Choices add “Heat exhaustion and heatstroke can often be prevented by taking sensible precautions when it’s very hot. During the summer, check for heatwave warnings, so you’re aware when there’s a potential danger. The government uses a system called Heat-Health Watch to warn people about the chances of a heatwave. This is a system of four different warning levels based on the expected temperature.”

But don’t be fooled by the temperature though, you can still be dehydrated in cold weather if you haven’t drunk enough fluids. Thankfully, whatever the weather, limiting the effects of dehydration is easy. We just have to drink enough water regularly throughout the day!


  • Water is best because it has no added sugar or salts
  • Water keeps your joints and eyes lubricated
  • Water maintains your strength and stamina

All essential for healthy living and healthy riding!

Dehydration Infographic
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August 8, 2023