Article by Dr Ali Hill, Sport and Wellbeing
WALKING ON THIN ICE
You’ve all heard “you are what you eat”. But did you know that what you drink can affect you too? Loss of only 2% of your body weight due to dehydration significantly reduces your physical and mental performance*, affecting your ability to think, react and respond. Headaches and dizziness are signs you’ve not drunk enough**.
WATER UNDER THE BRIDGE
The Department of Health recommends you drink 1.2 litres of fluid a day**. But this is just a guideline and your needs will vary. If you’re exercising, you need to make sure you replace all the fluids you lose in sweat. This is pretty easy to work out. If you weigh yourself before and after exercising, you want to be about the same weight. For every ¼ kg you lose, you should have drunk an additional 250 ml of fluid.
WATER, WATER EVERYWHERE
You also need to make sure you don’t drink too much as this can be as dangerous as drinking too little. If you’ve gained weight during exercise, don’t drink as much next time.
TAKING THE PEE
You can tell how hydrated you are by comparing the colour of your urine to a pee chart.
- Aim to drink enough fluid so that your urine is the colour of numbers one, two or three.
- If your urine is the colour of numbers four to eight, you need to drink more fluids.
- If you’ve had a multivitamin, your urine can become bright yellow, and using a pee chart will be difficult - the colour is caused by the high levels of vitamin B2. Try testing later in the day!
POURING OIL ON TROUBLED WATERS
Here are some top tips to help keep you hydrated:
- Drink before you get thirsty – when you’re thirsty you’re already dehydrated.
- Drink little and often throughout the day. This can help stop that full feeling you get from drinking too much.
THROWING THE BABY OUT WITH THE BATH WATER
Water is a great way to rehydrate if you’re exercising for up to an hour. After this, you’ll need to think about refuelling too. One of the easiest ways to do this is with sports drinks, which give you fluids to rehydrate, sugars to fuel your sport, and sodium to replace salts you lose when sweating. Many sports drinks available are isotonic; they have a similar carbohydrate concentration to body fluids and are good for rehydrating after training. Other drinks you can get are hypertonic; they have a higher carbohydrate concentration than body fluids and are good for refuelling after training.
Sports drinks needn’t be expensive. You can make your own at home for a fraction of the price of shop-bought drinks.