Fluids

Basic nutrition: fluids
The bottom layer of the sports nutrition pyramid contains basic nutrition. These are common products that you can buy in any supermarket: vegetables, fruit, dairy, nuts, fish, eggs, wholemeal bread, etc. These form the basis of healthy sports nutrition. This blog focuses on drinking fluids. How much drinking fluid should you consume per day, what happens if you don't drink enough and what are the best choices?

How much fluid should you drink per day?
The body needs fluids for many different processes such as temperature regulation, absorption of nutrients and transport of nutrients and waste products. The body consists of 40-70% water. The exact percentage depends on your age, gender and the amount of fat mass. Men consist of a slightly larger portion of fluid than women and the lower the fat mass, the more fluid your body contains. You lose around 2.5 litres of fluid per day via urine, feces, exhalation and via the skin (sweat). This number increases as you exercise more and therefore sweat more. To keep the body in balance, you need to consume an average of the same amount of fluid per day as you lose. If you do indeed lose 2.5 litres, this does not mean that you need to drink 2.5 litres of water. You get fluid from everything you drink, but food also consists largely of water. For example, most vegetables consist of more than 95% water and fruit and dairy products, such as milk and yoghurt, also contribute significantly to fluid intake. Drinking 1.5 litres of fluid is a good guideline to use. This is equivalent to about 6 large glasses of water.

What happens if you do not drink enough?
If you do not drink enough fluid, your body will dehydrate. Your body can go without food for a long time (weeks), but only a few days without fluid. If you lose more than 7-8% of your body weight in fluid, you will slowly lose consciousness. Especially if you exercise, it is a good idea to continue drinking enough, because losing more than 2% of your body weight in fluid can have a negative impact on your performance. So if you weigh 75kg before your effort and you weigh 72kg after your effort, then you have lost 3kg of fluid and this amounts to 3kg/75kg x 100% = 4% of your body weight. That is actually too much and therefore you would do well to take in fluids during your next effort. Weighing yourself before and after your effort is a great way to determine your personal fluid loss. The fluid loss is very individual and depends on the circumstances, such as altitude and temperature. What you lose in fluid, you have to replenish one and a half times. So if you weigh 1kg lighter after an effort, you actually have to drink 1.5 litres. This is because not all the fluid is absorbed and you also lose some of it through the urine. A clear symptom of a fluid deficiency is dark-coloured urine. Make sure that the urine is always light-coloured, especially when you start your effort.

What are the best choices to drink?
Water, tea and coffee are great choices to drink throughout the day. Coffee, especially when consuming 3-4 cups per day, does not have a diuretic effect and can therefore be counted as drinking fluid. During efforts lasting longer than 1.5 hours, it can be useful to use (isotonic) sports drinks to replenish fluids and carbohydrates. For efforts lasting less than 1.5 hours, water is sufficient. Athletes who drink a lot of sports drinks, just like people who drink a lot of soft drinks and juices, run a greater risk of tooth erosion. Limit the use of sports drinks, soft drinks and juices to the moments when you actually need them. Although low-calorie drinks, such as diet soft drinks, do not contain sugar, these are also not an optimal choice because the acids still attack the tooth enamel.