The truth about fitness and staying hydrated

Whether you're a seasoned athlete or you're just starting out in the wonderful world of physical fitness, we all need to stay hydrated when we exercise. Being aware of what you drink helps your body to get the most out of your activity, while it will also aid your recovery when you have finished.

The importance of hydration

Water plays a key role in every one of our bodily functions, and when we exercise we can lose up a litre an hour through breathing heavily and sweating. If we don't top these water levels back up again, our body is likely to become dehydrated. This can have a number of impacts on our general health, while it also makes it less likely that we'll get the most out of any exercise we choose to do. You're likely to feel tired more quickly than usual, and your body may also struggle to control your temperature.

Your muscles are reliant on water for fuel, so if you drink before, during and after exercise, you are likely to boost your energy levels, while it can also help you to avoid developing cramp.

Drinking before exercise

Many people can often forget about being hydrated before they exercise, but it is very important especially in warm weather.

If you aren't hydrated when you start exercising, your body temperature will rise faster and your heart will have to work harder, which will have a detrimental impact on your performance, and may also lead to heat stroke. You can avoid this by ensuring you drink enough before you exercise. The quickest way to test your hydration levels is to check your urine. If it is completely clear, you are fully hydrated and ready to start.

Fluids can take a while to absorb into your body, so drink steadily throughout the day. It can help to drink around 500 ml of fluid at least four hours before you exercise and another 250 ml in the 10 to 15 minutes before you start.

Drinking during exercise

When you are dehydrated, it is only natural that you will tire more quickly. Our bodies are made up of around 60% water, and our muscle cells are close to three quarters water, so a shortage of fluids makes things more difficult. Having drinks little and often during exercise, rather than a lot occasionally, will give you the best chance of getting the most out of your exercise regime.

Just how much you drink depends on how long you are exercising for, and how much you sweat. Your sweat levels can depend on a number of factors, such as your genetic make-up (some people sweat a lot more than others), your build (larger people sweat more than smaller people), your gender, your physical fitness, the conditions you are exercising in, and the intensity of your activity.

The best advice here is to listen to your body. If you feel thirsty, have a drink, and keep a bottle of water handy at all times where possible.

Drinking after exercise

After exercise, you'll need to drink to refresh yourself, but also to aid the recovery of your muscles. Drinking helps restore fluid levels around your muscles, and the quicker you start to replace these lost fluids, the sooner you'll recover.

Sometimes it is very tempting to have a beer after you have exercised, but drinking alcohol will remove water from your body as it increases the amount of urine your kidneys produce. This will slow down your recovery, not help speed it up.

Can you drink too much?

The short answer is yes. Drinking too much can cause hyponatraemia, a rare condition produced by drinking more fluid than your body loses. When this happens, the water in your body dilutes the salts in your system and can lead to swelling, which can cause a host of problems. How much you need to drink to develop hyponatraemia varies from person to person, but symptoms include headaches, feeling disorientated, nausea, vomiting, and muscle cramps. However, the condition is so rare because generally you would need to drink an awful lot for it to develop. It helps to be aware of it, but it should not put you off drinking before, during and after exercise.

Do I need to drink sports drinks?

The sports drink market has grown and grown over the last 20 years, so it is very easy to think they are a necessity for exercise. In reality, they are only really required for people who do a lot of strenuous training.

If you tend to moderately exercise for under an hour, you will be fine with water to hydrate yourself. If you exercise for any longer, sports drinks or even squash can help you keep going, as they replace lost fluid and contain both electrolytes and carbohydrates.

If you do use sport drinks, you should drink them after you have started exercising as you only start to use carbohydrates and lose electrolytes after you have started sweating.