Hydration and exercise
Before exercising always start every exercise session well hydrated. Drink 300-500ml of fluid in the 15 minutes prior to your workout.
During exercise aim to drink 150-250ml every 15 minutes to offset fluid losses - drinking smaller volumes more frequently minimises stomach discomfort. Remember, the more you sweat, the more you need to drink.
After exercise how much fluid you need depends on how much you lost, but you'll probably need at least 500ml. Try to drink 1.5 litres of fluid for every kg of weight lost during exercise, or keep drinking until you pass light-coloured urine
Which fluid you opt for depends on how hard you exercise, and for how long. However, choose a flavour you like to encourage you to drink more.
If you're exercising at a low-to-moderate intensity for less than an hour, then water is great.
If you find it difficult to drink large quantities of plain water, try adding some juice or squash, which will also provide you with some carbohydrates to help restock glycogen stores.
If you work out continuously for more than an hour, then a sports drink would probably be a good idea.
Sports drinks help maintain better fluid levels, plus the added carbohydrates provide vital glucose to help avoid fatigue. Most sports drinks are five to eight per cent carbohydrate, which makes them 'isotonic' - a similar concentration to blood - and, therefore, quickly absorbed.
In addition, sports drinks contain sodium to stimulate sugar and water absorption, and replace the sodium lost in sweat. This added sodium is particularly useful if you're a 'salty sweater' - where your sweat is opaque, tastes salty, and leaves white marks on your clothes. The sodium has the added benefit of encouraging you to drink more.
In fact, the drive to drink is present for several hours following exercise (it stops when you eat). However, when your mouth is moistened with fluid, your body automatically signals your brain to stop drinking. This inhibition can happen before the body's fluid levels have been completely restored. This means that even if you don't feel thirsty, you're not necessarily well hydrated, so it's important to keep drinking fluid throughout the day.
Although alcohol in moderation is fine, it's not a good idea to drink it just before exercise. You also need to rehydrate properly before drinking alcohol after exercise. Alcohol before exercise not only has a detrimental effect on co-ordination skills and exercise performance, but also increases the risk of injury. Furthermore, alcohol can cause dehydration and slow down recovery from injury.