Different types of diet
We will recall briefly the foundations of human diet, apart from vitamins and minerals such as calcium, iron, etc., which also have an essential role to play in our biological equilibrium :
- Proteins : indispensable as muscle building material, even if they are not normally used as a fuel during usual exertions.
- Fats or lipids : the fuel of our daily lives.
- Carbohydrates or glucids: source of muscular and hepatic glycogen and blood sugar.
It is the wonderful metabolism of all these elements which ensures our life and equilibrium. Relying, as we said at the beginning, on a study of numerous works, publications made at scientific congresses and recommendations made by specialists in the preparation of athletes (particularly for the next Olympic Games), we are going to attempt to describe certain types of diet, setting out the basic components (as percentages of the total number of calories). Normal balanced diet (according to level of physical activity) :
- Proteins 13 %.
- Fats 25-35 %.
- Carbohydrates : 52-60 %.
(It should be noted that the percentages given for proteins and fats are taken from the recommendations of the WHO and are in practice adopted by all countries. Such a breakdown cannot be really classed as a true athlete’s diet.)
Athlete’s diet (recommended in many countries. This is of course a diet to be used during
intensive training, i.e. twice a day) :
- Proteins 13 %.
- Fats 26 %.
- Carbohydrates 61 %.
High-carbohydrate diet :
- Proteins 17 %.
- Fats : 7 %.
- Carbohydrates 76 %.
High-carbohydrate diet (with previous exhaustion of stocks of glycogen) :
- Proteins 17 %.
- Fats 7 %.
- Carbohydrates 76 %.
“Scandinavian dissociated diet” type of diet
Lipo-protein phase :
- Proteins 20 %.
- Lipids 70 %.
- Glucids 10 %.
Carbohydrate phase :
- Proteins 17 %.
- Fats 7%.
- Carbohydrates 76 %.
IMPORTANT RECOMMENDATIONS
We give here some essential rules which are too often overlooked :
1. Simple sugars (table sugar, sweetened drink, glucose, etc) should never exceed 10 % of the total number of calories.
2. Special diets (high-carbohydrate or “Scandinavian dissociated”) should never constitute a normal diet, but be reserved for exceptional conditions (important competition). It is indispensable to experiment with them beforehand at less important events.
3. All the high-carbohydrate diets demand a greater intake of liquid (at least an extra 1 ½ litres).
Each gramme of carbohydrate fixes 3 grammes of water and it is therefore vital to provide this extra liquid. An easy way of checking this type of diet is by weighing oneself. Using this formula, one should put on 2-3 kilos. The excess of water will disappear during exertion. Moreover it constitutes a good reserve that can be used during a marathon, particularly in warm weather; it will limit dehydration, which is a important risk factor for our bodies and in diminished performance.
4. It is always recommended to have diet programmes drawn up by a doctor or a dietician to take into account vitamin and mineral trace requirements. There must be a correct division of requirements in calories between the different percentages (a foodstuff is not composed solely of glucids or carbohydrates, but also of fats, proteins).
5. There is no contra-indication for an insulin-dependent diabetic taking part in a marathon-type effort, but it obviously requires particular attention to be paid to certain dietary problems. It is therefore useful to discuss this beforehand with a medical specialist. In theory, it is preferable for a diabetic not to apply the formulae strictly which we have discussed, but complete treatment of this subject would be too involved.
6. For the last meal, the day before the race, it is possible to choose a breakdown of one’s own choice since it is no longer of any importance with respect to the storage of glycogen. However it is still a good idea to remain within reasonable limits. We have said absolutely nothing about what happens in respect of diet on the day of the competition. We will merely say that the last meal should be taken at least three to four days before starting, and should be extremely light.
7. We have not taken into account in the calorific breakdown of the various types of diets the part represented by alcohol in all its forms (wine, beer, etc.).
8. It is the “Scandinavian dissociated diet” which, in most cases (the physiology of man is very complex and certain subjects may react differently), gives the best results
It includes during the first “intense exertion + lipo-protein diet” phase psychological restraints which in some cases are considerable. They call for an effort of will; it is up to the athlete and the coach to decide by drawing up a balance of its positive and negative aspects.
9. There has been much talk of digestive or other problems which may arise in the use of some of these diets. We would recall that at the congress in Saint Etienne which was held in July 1979 and which covered all the problems of diet, the international experts who took part in this scientific meeting were unanimous in declaring that to their knowledge nothing serious had ever appeared in all the time it had been practised, which is more than ten years now. Costill even said that he knew some marathon runners in the United States who use a high-carbohydrate diet very regularly during the competition season when they are taking part in many marathons, and that they have not had any trouble of any kind.
SUMMARY
The author describes the athlete’s diet on the basis of the most recent scientific works, The athlete’s nutrition depends on the type of exertion, its duration, its intensity, and which muscular fibres are used. This study is limited to the needs of the long-distance runner in energy substrates during intense exertion (75 % of oxygen consumption) of long duration (longer than 60 minutes). The most interesting discoveries concern the role of the stocks of glycogen. The higher these are, the longer the exertion can be continued at a high speed. The reconstitution of the stocks of glycogen by means of a high-carbohydrate diet after exertion is an extremely favourable element for rapid recuperation, training or competitions at short intervals possible. The last important point concerns the breakdown of the different nutrients in man under exertion. It is considerably different from the diet consumed by the average Frenchman.
This breakdown gives a much larger proportion of carbohydrates :
- Proteins : 15 %.
- Lipids : 25 %.
- Glucids : 60 %.
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