It is important that athletes consume sufficient building materials to help build up cells. A muscle consists of thousands of cells, which can be damaged by exercise. This damage must be repaired in order to prevent muscle degradation and facilitate muscle growth. Fat and protein are important sources of building materials, and are therefore essential for athletes.

In general, athletes require more protective nutrients in the form of vitamins and minerals. Due to overworking and excess fertilisation, our agricultural land has been degraded, so that fruit and vegetables now contain less vitamins and minerals than roughly 50 years ago. This lower level of vitamins and minerals, combined with lower consumption of fruit and vegetables in general, means that athletes have to pay extra attention to consuming sufficient fruit and vegetables in their diets. Variety is also very important here.

Our level of performance is directly proportional to our loss of moisture. With this in mind, it is important that we pay enough attention to hydration. Drinking enough before, during and after exercise is of crucial importance to preventing dehydration and loss of performance.

1 Hydration

We can live for 30 days without food, but only 3 days without water. This is because our body is 70% water. Our muscles are even 75% water, and that is the reason why an athlete may suffer a loss of performance if he or she does not drink enough. Studies have shown that as much as 2% sweat loss already has a noticeable effect on performance. Hydration has a directly proportional relationship with exercise tolerance, so we can simply deduce that drinking enough improves performance.

It is important to drink enough before exercise. Pre-hydration starts the day before exercise, and mainly involves drinking water. 3 hours or 10 minutes before the exercise, you could drink a sports drink. One way to see whether you are hydrated enough is to check the colour of your urine. Dark yellow urine is a sign that you have not drunk enough fluids. A light yellow colour indicates that you are well hydrated. In addition to losing moisture, athletes also lose salts (electrolytes like sodium, potassium, calcium & magnesium) while sweating. These are crucial to retain moisture in the body. These electrolytes must therefore also be consumed.

There are a great deal of different sports drinks, but they can be divided into 3 types based on osmotic pressure:

Hypotonic sports drink:

In a hypotonic drink, the concentration of dissolved particles per 100 ml of sports drink is lower than in the blood. This allows the fluid in a hypotonic drink to be absorbed faster and more effectively by the body. It therefore provides a lot of moisture but not much carbohydrate. An example of a hypotonic sports drink is water.

Isotonic sports drink:

In an isotonic drink, the concentration of dissolved particles per 100 ml of sports drink is approximately the same as in the blood. Because of this concentration, the fluid can be absorbed into the body faster compared to a hypotonic sports drink. So, the drink supplies a lot of fluid, as well as energy. An example of an isotonic sports drink is Etixx Isotonic.

Hypertonic sports drink:

In a hypotonic drink, the concentration of dissolved particles per 100 ml of sports drink is higher than in the blood. These sports drinks have the highest osmotic pressure. The moisture in hypertonic sports drinks is absorbed slower than water. The purpose of these sports drinks is not hydration, but rather the supplementation of lost energy. An example of a hypertonic sports drink is Etixx Carbo-Gy.


Since we need both hydration and energy during exercise, an isotonic drink like Etixx Isotonic is preferable. If you are exercising heavily for a long period of time, you could choose to consume a hypertonic sports drink like Etixx Carbo-Gy.

The amount of moisture that you lose during exercise depends on duration, intensity, genetics, body size and various environmental factors such as humidity and temperature. It is therefore not entirely clear how much you should drink while exercising. A general guideline is half a litre of isotonic sports drink per hour. During hot weather, this amount can even be doubled.  A very good way to determine how much moisture you need to consume is to use some scales on a day during which you will be training. Weigh yourself before and after training, and multiply the lost weight by 1.5. The outcome is the quantity of fluid that you need to consume in order to compensate for what you lost as sweat.