Food

Sources of energy: The most important fuel for our muscles are carbohydrates. Carbohydrates can be found, among others, in bread and potatoes. After they are absorbed by the body they are transformed into glucoses. Glucose (stored in the muscles) is used to let a muscle contract. Fat particles can also be used as a source of energy. For us they are of less importance. For some of us they are even annoying. You only use fat particles during long duration runs. The disadvantage of fat burning is that less energy will be released. I.o.w. fat burning causes you to do a sport in a less active way, hence, you run less fast. These 2 energy systems are simultaneously active, by the way. At training sessions with a maximum of 75 minutes you can get all your energy from the glucose present. With races of 5 till 10 kilometres too, there will be enough energy readily available within the body. With a half marathon it might be the case that your glucose source might get depleted during the race. How to prevent this?

The average food pattern of the Dutch population consists of: 15% proteins, 40% fat and 45% carbohydrates. Check this out for yourself!

During a training/race: Try not to eat when you?re right before an intense training session or a race. It?s important that your stomach-intestine tube isn?t too full. A full stomach can give cause for pressure on the stomach, vomiting tendencies or even actual vomiting. Moreover, the blood will retreat itself significantly from the digestion organs (stomach, intestines and the pancreas) during running. This leads to a relative shortage in the blood level of the stomach-intestine tube. And that?s exactly the place where the blood is needed in order to digest food. The higher your running velocity, the bigger your chance to experience stomach and intestine complaints. Long slow duration runs give less cause for stomach and intestine complaints compared to intense interval training exercises. Stress and tension before a race will also increase the chance of this kind of complaints. You only have to think about marathon runners who end up at the toilet halfway the marathon after they?d prepared for three months. So, eating when you?re right before a training session or a race can cause problems. It can cause dizziness too. Because there?s a double ?insulin working? there won?t be enough glucose flowing towards the brains. What you can do is consuming an isotonic energy drink 1 minute before the starting shot. Then you won?t be bothered by this. Most of our food can?t be used as a source of energy or as fuel before some sort of digestion process has been taken place. After a ?diminishing treatment? the nutrition?s will be able to get absorbed into the blood via the intestine tube. The emptying of the stomach depends on several factors: -consistency of the food: liquid faster than solid food. Well chewed better than big chunks. ?the composure of the food: carbohydrates faster than fat. (this indicates, among others, whether carbohydrates are slow or fast).

Furthermore, we have slow and fast carbohydrates. When you consume fast carbohydrates (like energy drinks, dextrose, cornflakes and rice-waffles) right before a race this can cause, as mentioned earlier, trouble. Slow carbohydrates can work out positively. Slow carbohydrates (nuts, pure chocolate, prunes, grapefruits and milk) stimulate the use of fat burning. By this carbohydrates will be saved and your energy supply will last longer. You will notice this at long(er) duration runs. Longer than one and a half hour. Try to experiment with this, but don?t do this before a race. This won?t have any effect for short distances. It only might have effect on distances of 16k or longer. But only consume small quantities. It will take care of a constant, moderate release of glucose to the blood. And by doing this, saving the glucose supply.

Save the fast carbohydrates for after a training and race. This way your energy shortages will be replenished faster.

What should you do in order to prevent that your energy supply (supply of glucose within the body) will get exhausted during a half marathon?

-Take care of a well-trained fat burning system (see the information in the article ?duration run?). By this ?sugars? will be saved.

-Eat a couple of days before the race more carbohydrates and less fat. By doing so you will create a bigger supply within the body.

Take some extra energy during the race. Liquid food is more easily digestible than solid food. Squeezie and other brands of liquid food are available at Runnersworld which is located on the Vijzelgracht. You can take this jelly 1 or 2 times at least 20 minutes before the end of a race. With the help of some water you flush this energy boost inside. By doing this you?ll feel after 10 minutes that you got something extra again. But when you start doing this then don?t start during a race but first try to experiment at long distance runs or interval exercises. When a half marathon takes you at least 90 minutes, it is advisable to start experimenting with this. People who finish the Dam tot Damloop within 90 minutes, they don?t have to eat during the race. Drinking is important for races longer than 45 minutes, especially when it?s warm.