© G.Mondelli Studio - Italy

THE NUTRITIONAL VALUE OF PASTA (II)

 

Pasta, basic food for the pre-competition meal of sportsmen

Man has always, through diet manipulation, tried to improve his physical performance, however, the nutritive question of sportsmen has usually been discussed without a scientific basis, because of research in this field being scarce and insufficient, with no real experience.
Very recently, on the nutritive question of sportsmen, a little clarity has been given even if many prejudices not supported by precise specifications still dominate the field, not so much at professional sport level, usually controlled by highly qualified medical and technical staff, but rather than at level of youths or, more generally, of sport amateurs.

 

Nourishment, fuel for the human machine

Nourishment is our fuel: to obtain an optimal performance of the human machine it is consequently necessary to know both fuel and machine very well. Nourishment is to be distinguished into energy-giving (that is able to supply mechanical or caloric energy by transformation of chemical binding energy through the oxidation process) and non energy- giving foods. As well known, energy-giving foods are lipids, supplying 9 Kcal/g, proteins and glucides, supplying 4; non energy-giving foods are water, vitamins and minerals, not able to supply caloric or mechanical energy, but nevertheless necessary, in suitable and adequate quantities, for the human machine functioning (like water for a radiator and oil for motor lubrication). The human machine needs to employ fuel for its maintenance, but its needs change in relation to the physical activity (that can be work, amusement or sport) and to its duration. It is estimated that, on average, for the motionless maintenance of the human machine about 1,700 Kcal are necessary, to which we must add additional calories proportional to the type and length of muscular work. In case of sport activity, the additional calories needed can be considerable: for example, the energetic needs during swimming activity carried out for pleasure is 10 Kcal/m' (Travia-Fidenza and Liguori-Topi); equal to 600 Kcal/h, but if swimming is carried out at competition level, when the factor "speed" is required, the energetic cost rises to 25 Kcal/m', that is to 1,500 Kcal/h: almost 3 times more! Practically speaking, consumption is not only tied to distance and length, but also to speed.

 

Fuel for muscolar activity

How is it possible then to meet these fuel increased needs of the human machine when muscular activity becomes intense and protracted and the energetic request is so high? Essentially by supplying energetic nourishing principles, such as glucides, lipids and proteins and keeping a balance in the additional share according to a report of 4-2-1, that is the additional energy will be supplied respectively for 55-60% by glucides, for 30% by lipids and for 15% by proteins, and not only by sugar as some still erroneously suggest.

The nourishing principles supplying energy for muscular contraction are essentially represented by glucides and lipids which can then be considered as the real fuel for the human machine and, particularly for its "muscular engine"; such use changes though according to the length and strength of the exercise the "engine" must do, while proteins contribute only a little, with glucogenetic and lipogenetic aminoacids, especially when activity is strong and protracted.
"Muscular engine" for its mechanical activity employs glucides and lipids as fuel; for example, in conditions of rest our muscles take energy for 87% from fatty acids and only 13% from glucides. For slightly heavier work or for a short athletic activity, the energetic needs are covered for 50% by sugar. For very intense work and/or with a duration of 3 hours or more, again fats are mainly used, at the rate of 70%, to supply the muscular engine with energy (Fox, Proja, Creff and Berard, Topi). And here comes the first important point about protein contribution: in fact proteins are not necessary as fuel and in sportsmen the protein daily need is constant and equal to almost 1 g per kg of body weight, it can raise to a maximum of 2 g/kg/day, when it is necessary to develop muscular masses, as during the training period, or during developing age, when a growing process is in action.
An increased protein contribution is not useful at all, especially in a pre-competition meal. Actually, in the meal preceding a sport performance a prevalent consumption of proteins can even be dangerous!
Contrarily to common belief, a similar meal (such as the classic steak & salad) causes a series of harmful consequences on the sportsman's performance. Firstly because it involves a considerable digestive trouble with consequent subtraction of blood at the level of the splanchnic or visceral vascular bed prejudicing the muscular supply. Then a hyper protein meal also needs the draining of catabolic products from the nitrogenous metabolism, which must be eliminated through the renal duct, when it is well known that during a very taxing athletic performance the kidney is ischemic due to a 90% reduction of the renal plasmatic flow. So, with a hyper protein meal the renal work is made heavier, when it is already under stress due to the contemporaneous presence of toxic substances from the "muscular work".

 

The pre-competition meal

The pre-competition meal must then be mainly gluco-lipidic in all aerobic sports, that is of duration, because glucides and lipids are the two fuels employed when muscular exercise exceeds 20-30 minutes. Naturally food must be taken almost 3 hours before the competition, it must neither be particularly rich nor abundant: composed with complex sugar (starch) produced by common foods (bread, pasta, potatoes, etc.), added with lipids and with a reduced portion of proteins to modulate the muscular employment of glucides (Siliprandi, Creff and Berard, Topi, Proja, Ticca).
Among lipids, the short chain fatty acids are more quickly mobilized and metabolized and have a turn-over 40 times higher than glucose and equal to less than 3 minutes, especially if with Carbon atom chain lower than 12; therefore vegetable oils or butter fats are to be preferred (Siliprandi; Creff and Berard).

Particular behaviour is given by the oleic acid that is a preferential energetic tonic for the muscle particularly if training for resistance sports (!), so olive oil is recommended as such (Arrigo and Rondinone). A portion of pasta, normally served with tomato sauce and olive oil or butter, would be ideal, as reported in the table from which it is clear how much the percent distribution of calories, derived from proteins, lipids and glucides, respects the suggested proportion of 1-2-4. The attempt to improve athletic efficiency with overdoses of "complex" and, even worse, "simple" sugars just before the effort, is completely illusory and often dangerous, since it may induce hyperglycaemia, insulin and secondary hyperglycaemia responses, worsened by the effort (Fink and Costill, Wootton and Coll., Sherman and Coll.).

 

Good balanced diet to play sports

To conclude, those who play aerobic sports need a good balanced diet (Creff and Berard; Topi; Stordy). The greatest energetic help must be obtained always respecting the proportion of the three energetic principles according to the ratio of 4-2- 1 (60% of Kcal from glucides, 25-30% from lipids and 15% from proteins), as already stated. Special food as well as special integrators are only necessary in extraordinary circumstances and always under the cautious control of a doctor, taking into account the sportsman's health above all, rather than the exaltation or the exasperation, not completely harmless and often dangerous, of his athletic performance.
Only in some cases vitamins and hydrosaline supplements may be permitted, especially in the "pre-competition" or "recovery" phase (Turchetto, Topi, Creff and Berard).

from magazine "PARMA, food valley heart", by Andrea Strata, 1993


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