On a physiological level, the characteristics of our "biological engine" (how our body works) are well defined and, essentially, unchangeable.
The biological engine, with respect to a mechanical engine, has a great advantage as it can function with different types of fuel (or in biological terms, substrate) in the forms of fats, sugars, proteins and alcohol.
If we ignore alcohol and only consider fats, sugars and proteins, we can see that the choice of ‘fuel’ is made independently by muscle cells based on:
Therefore, when addressing the problem of food in sport, we have to keep in mind the metabolic choices carried out independently by the body.
The field of physiology has clearly clarified how many calories each sporting activity burns and how many calories each type of energy source provides. The same goes for another aspect that characterises sports; our salt-water balance. It is a known fact that doing sport, especially in particular weather conditions, causes perspiration therefore the question is, how much and what to drink? This is hard to answer for all situations since some can be so extreme that the recommended amount is not appropriate. The basic rule is that, the more you work the more you should consume however it could be that, following the gradual decline in physical activity in everyday life, the basic rule of adapting our diet to the work load is no longer completely valid.
|It must be added, for reassurance, that the human race evolved as a race that
was essentially migratory and not sedentary and it has faced many endless and
tiring journeys in its time, trusting only in the strength of the legs and the
food available at the time.
Here is a list of some famous journeys:
... the crossing of the Bering Strait (who knows when!!!) by the Asian population on their way to what is now North America;
... Hannibal crossing the Alps in 218 B.C. (along with 58 elephants);
... the crossing of the Great St Bernard Pass by the Napoleonic army on the 20th May 1800;
... the climbing of Everest by Hillary and Tenzing in 1952.
Let us overlook the crossing of the Bering Strait and Hannibal’s journey for now as it is thought they did not take food or drink with them. It is known, however, that Napoleon sent food parcels to his emissaries in Valais which contained products that were chosen carefully to compensate for the brave soldiers’ fatigue, soldiers who had to drag (along with mules) pieces of artillery up to heights of 2,472m. They also asked villagers to prepare packages of biscuits and dried meat for them. The food eaten by Hillary and Tenzing in the mornings is also known, thanks to the notes written by Hillary; tinned sardines with honey and lemonade as a drink (maybe because they did not have anything else).
All of this shows that the biological motor’s metabolic resources are quite incredible and perhaps its most important characteristic is adapting itself to ever-changing conditions?
What we know about food today and what is available to us in terms of food made specifically for physical activity, would have helped Hannibal and his company and the Napoleonic soldiers immensely, as well as everyone who runs, climbs and cycles today, and people who are yet to do so.
In general, the diet recommended to us is based on the food guide pyramid:
||Going from the bottom of the pyramid to the top symbolises a progressive reduction in the consumption of certain foods. The base of the pyramid is filled with bread, cereals, rice and pasta, above this you can find a band that is equally split between fruit and vegetables and above this, another band, also equally split into two groups; meat and dairy products. The section at the top is smallest section and is filled with fats and sugars.|
Fundamentally, the pyramid says that our diet should be made up of:
Do not be shocked by the low amount of fats we should consume (30-40g); fats contain 9Kcal/g, whilst sugars and proteins only contain 4Kcal/g.
Of course, diets can vary according to a person’s individual characteristics, the physical activity they do and level at which it is practised.