As an athlete, you can only perform at your best if your body is functioning optimally. And our bodies can only function optimally when they get the nutrients that our cells really need. The image above shows what an athlete, regardless of the sport he or she takes part in, needs to function optimally. Fuel, building material, protective nutrients and hydration are 4 essential components that an athlete needs for this. If an athlete neglects 1 of these components, then his or her performance will suffer. The fuel and building materials are considered macronutrients; these are carbohydrate, fat and protein. Protective nutrients are the micronutrients that contain vitamins and minerals. Hydration obviously refers to liquids.
You can only exert physical effort when you body/muscles are getting enough fuel. This is logical, since physical effort requires muscular work, which is only possible when there is sufficient energy for our muscles to function. You could compare this to a car with an empty petrol tank. The car won’t get very far, and neither will an athlete if he or she has not filled up with enough fuel before or during activity. Carbohydrates (sugars) are the best source for delivering fuel and generating muscular work. Fats are also capable of supplying energy, and have the advantage of being able to supply more energy than carbohydrates. 1 gram of fat contains 9 kcal, while 1 gram of carbohydrate only contains 4 kcal. But fats suffer the disadvantage of not being viable as a fuel in every sporting scenario. An athlete can only use fat as an energy source if several requirements are met:
- Firstly, there must be sufficient oxygen supply to burn fat. Research has shown that the effective burning of fat requires that the heart rate does not exceed 60-70 per cent of the maximum heart rate.
- Carnitine is an important compound that is required for burning fat. Without carnitine, an athlete will burn fat less effectively. This is important information for vegetarians, since animal products are rich in carnitine.
- An athlete who is less well trained in the use of fat as an energy source will have trouble using fat when exerting effort. Training after fasting is the best way to train your body to use fat for energy. During training after fasting, our bodies are forced to use fats instead of carbohydrates. In doing so, the body produces fat burning enzymes that we need to convert fat into glucose. During a competition, an athlete who does not have these enzymes will have more trouble burning fat and will only be able to use carbohydrates.
Carbohydrates are an important energy source for our bodies, especially for muscles and our brains, and are therefore very important for athletes. In addition, they are a source of dietary fibre that assists in the development of healthy gut flora and numerous digestive functions. Carbohydrates, sugars, glucose, fructose, starch,... there are numerous types and denominations that can be classified as carbohydrates. In fact, carbohydrates are chains of monosaccharides like glucose, of varying length. The disadvantage of these chains of glucose is that they cannot simply be absorbed and used as energy. The glucose molecules must first be separated from each other, because single glucose molecules can be used as fuel or stored as glycogen. From this, we can conclude that all of the carbohydrates that we consume during the day are absorbed into our bodies as sugar and directly affect our sugar metabolism. Generally, the following applies: the more complex the carbohydrate, i.e. the more sugar molecules are bound to one another, the harder it is to digest and the healthier the carbohydrate is.
Just like the petrol tank in your car, your body can store carbohydrates in the liver and in the muscles. The disadvantage is that the storage of glycogen (carbohydrate reserves) is limited. A trained male athlete can store approximately 700 grams of glycogen, and a trained female athlete just 580 grams. This quantity is only enough for 90 minutes of intensive exercise. If your exercise takes longer, then you will have to continuously consume carbohydrates in order to prevent your body running out of fuel.
The various types of carbohydrates can be roughly divided into 3 categories. These categories relate to the structure and the speed at which certain carbohydrates are absorbed into the bloodstream (i.e. the glycaemic index) and can then be used.
- Slow carbohydrates (low Glycaemic index): oats, whole-wheat pasta, quinoa, unripe banana, apple, broccoli,...
- Half fast carbohydrates (moderate Glycaemic index): spaghetti, couscous, raisins, bread, ripe banana, dates,...
- Fast carbohydrates (high Glycaemic index): rice, chocolate spread, fizzy drinks, jam, cornflakes
As an athlete, it is important to avoid strong fluctuations in blood sugar levels throughout the day, since this can cause you to feel faint, tired and lethargic (hypoglycaemia). On the other hand, during exercise carbohydrates must be absorbed as quickly as possible, otherwise there is no point consuming carbohydrates when exercising. Another important fact to take into account is that it is inopportune for an athlete to consume fast carbohydrates on a day to day basis, because of the limited storage capacity. For this reason, the timing of consumption and the type of carbohydrate are 2 extremely important factors for athletes. The guidelines regarding the timing and type of carbohydrates are shown below.
- Day-to-day: Slow carbohydrates
- Day before exercise: Half fast carbohydrates
- During exercise: Fast carbohydrates
We need protein in our diet, not just for the growth of our bodies but also for their maintenance. For example, healing wounds, protection against pathogens, the replacement of old cells and the creation of new muscle tissue after exercise. At 22%, our muscles have the highest protein concentration of all tissue. For this reason, high quality sources of protein must be available as part of an athlete’s daily diet in order to maintain and build up muscles, ligaments and bones after exercise. Muscle growth allows us to store more carbohydrate reserves and causes a rise in the number of mitochondria, which allows more energy to be produced.
Animal products are the best sources of protein. A handy tip here is that the best sources of protein are animals that run, fly or swim fast. Some examples are fish, chicken, duck and hare,... However, this does not mean that steak does not contain any protein. Only that steak also contains high levels of saturated fat, so it is not the ideal source of protein. Further, nuts and legumes are 2 very good sources of protein. Of course, let’s not forget eggs. 1 egg contains 7 grams of protein.
The daily requirement for an athlete is between 1.5 and 2 grams per kilogram body weight. This is almost double the requirement of a non-athlete. So, a 70 kg marathon runner requires 112 grams per day. In case of injury it is important that this protein requirement is doubled to 3 to 4 g/kg body weight. This is because an injury involves physical damage that must be repaired using building materials (fat and protein). Below, you will find several situations during which additional attention must be paid to protein consumption:
- Start of the season or an intensive training period
- For strength training
- Athletes with a slim build
- Young athletes who are growing
Isotonic sports drink rich in carbohydrates, with a 2:1 (glucose:fructose) sugar combination and with electrolytes.
Magnesium 2000 AA
Magnesium supports normal muscle function.
30 effervescent tablets
Energy drink / a carbo loader for intense endurance events.
Modern day athletes are warned against anything that contains fat “Fats are bad and should be avoided”. Because of this, some athletes never consume fat, and this is detrimental to their health. Fatty acids are used as building materials by our body for, among other things, cell membranes (in our muscle cells for example) and for all kinds of active molecules that are required for various processes in our bodies. It goes without saying that these processes cannot occur optimally with a low-fat diet. In addition, fats are an extremely important source of energy for athletes, since the amount of energy that can be stored as fat is much higher than what can be stored as glycogen (carbohydrate reserves). Furthermore, we must not forget that the most important organ in our body, the brain, is made up of 50-60% fat.
Fat is an essential component for athletes and non-athletes alike. There is a wide variety of types of fats, each with their own functions, properties and health effects. A quick distinction can be made between saturated and unsaturated fats, whereby the unsaturated fats can be further divided into monounsaturated and polyunsaturated forms. The so-called industrially synthesised trans-fatty acids are another category, and have nothing but negative effects on your health, which is hardly surprising considering that these trans-fats are mainly found in fast food and other manufactured foodstuffs.
In particular, the polyunsaturated omega-6 and omega-3 fatty acids form the basis of an optimal fat metabolism. Omega-6 (mainly found in meat and vegetable oils) and omega-3 (found mainly in oily fish) are an essential part of our diet and affect our health through a variety of processes. These 2 fatty acids play key roles in inflammatory processes, whereby omega-6 has a powerful inflammatory effect, whereas omega-3 has a strong anti-inflammatory effect. The problem is the balance between the two fatty acids in our current diet, in which the consumption of omega-6 fatty acids is usually much higher when compared to the consumption of omega-3 fatty acids. Due to the imbalance, we are in a state in which inflammation is constantly stimulated, and the suppression and control of this inflammation is not strong enough. The solution? Strive for an optimal balance between omega-6 and omega-3 fatty acids by eating more oily fish, and eating less omega-6 fats which are found in all forms of butter, sunflower oil, palm oil, corn oil, evening primrose oil,...