Eating habits of female soccer players and consequences for sporting activity

With her PhD theses Ms Leyre Gravina wished to show that to be a good sportsperson, apart from having talent and being fit and in training, eating habits were also important. To this end she ventured into the dressing rooms of the top two female teams of the Athletic (Bilbao) football* club and observed what and how much they ate. She concluded that, just by changing one or two bad habits, the sportswomen could achieve a body that suffers less during matches, thus increasing the possibility of enhancing sporting performance.

Ms Gravina evaluated players from the first two Athletic teams (Superleague and National League), in order to observe their eating habits and where they could improve. The evaluation lasted a week and the studies were carried out on the days prior to the match, on the same day of the game and after the match.

Using this data she wrote her PhD thesis: Estudio nutricional en mujeres futbolistas de élite y su relación con los cambios hematológicos, de estrés oxidativo y daño muscular tras jugar un partido de fútbol (Nutritional study of top-class women footballers and the relation with changes in haematology, oxidative stress and muscular damage after playing a football match).

Playing football game triggers a whole series of reactions in the human body. With the leucocytes or white blood cells, for example, Ms Gravina was able to observe that, due to the physical exertion involved, those of the neutrophyle type increased in number while the lymphocytes diminished. Moreover, the resulting lack of lymphocytes facilitates infections. Also notable was the muscular and cell damage involved and the alterations in electrolytes and hormones.

At the same time, Superleague players have greater antioxidative capacity than those of the second team, meaning more effective muscular contraction, less risk of inflammation and greater capacity of organisms to combat the toxicity of free radicals. Nevertheless, it has to be taken account that the body receives greater punishment at matches than in the second team fixtures -- suffering greater cell damage, rupture of red blood cells, tiredness and dehydration.

Those in the Superleague, somewhat better

In order to carry out physical activity correctly it is essential to have the required nutrients for the body. According to Ms Gravina, this depends on eating habits and nutrition.

According to the researcher, the eating habits of the Superleague players are better than those of the second team. They ingest less protein and fat and more fibre. Moreover, the percentage majority of energy consumed due to physical exertion comes from carbohydrates and not fat. In any case, neither of the teams eat correctly. To start with, they do not ingest sufficient carbohydrate. Moreover, their hydration is insufficient and this causes an increase in heartbeat. The percentages of electrolytes are also inappropriate, as they ingest too little potassium and too much (double the required amount) of sodium and chloride. As Ms Gravina pointed out, potassium is fundamental to guarantee electrolytic equilibrium, essential for correct neuronal transmission and for the mechanisms in active transport.

Moreover, Ms Gravina also observed deficiencies in those substances that make metabolism possible. Players from both teams lacked folic acid, vitamin D, calcium, iodine and fluoride; moreover, those in the second team did not have sufficient magnesium. The researcher wished to underpin that these nutrients are highly important for sportspeople: vitamin D, calcium and fluoride for the bones, iodine for the metabolic process in general and magnesium for the various functions that affect muscular functions.

Enhancing performance by changing eating habits

Given all this, in the view of Ms Gravina, effective measures can be taken that affect nutrition and enhance sporting performance, and she makes a number of proposals to this end. For example, the number of red blood cells increases with greater ingestion of proteins, folic acid and vitamin C. To counteract the inflammation caused by physical activity, she points to vitamins, carotenoids and certain vegetable-source substances. In order to combat oxidation, on the other hand, she mentions carbohydrates and fibre and certain vitamins and vegetable-source substances. As regards reducing cell damage, she proposes, amongst other things, ingesting fibre and carotenes. With these and other examples, Ms. Gravina has tried to demonstrate that, through developing new eating strategies, body changes caused by sport activity can be reduced, thus enhancing performance.