Swimmers should eat 16 fluid ounces (or half a litre) of water or a sports drink two hours before workout to help hydrate them. Swimmers should bring a plastic water bottle to every training session. This allows them to fill up their bottle with clean drinking water and avoid buying expensive drinks on site. During exercise, your body loses water through sweating and urine. You need to replace these fluids by drinking appropriate amounts of water and other liquids. All types of fluids are important for keeping you healthy during exercise. Some people may get thirsty more easily than others. This is normal but it does mean you should try to drink up to 150 ml (5 oz/1 cup) of fluid per hour if you are feeling dry. You should only drink alcohol with meals or after a hard workout. Drinking it alone can cause serious problems with concentration and judgment while cycling. Alcohol also increases the amount of sweat you produce, which could lead to dehydration. As well as being unhealthy, drinking too much alcohol can also affect your performance. Research has shown that cyclists who drink any type of alcoholic beverage experience increased heart rates and blood pressures when riding. This is because alcohol affects the way your body responds to adrenaline. It is also possible to become dehydrated after drinking too much alcohol over a few hours. When this happens, you will feel dizzy and tired.