Playing tennis can be accompanied by profuse perspiration, which under warm climatic conditions can be a considerable amount. As a result, one always has to be careful to take enough fluid with the necessary mineral content, as well as vitamins and trace elements. Potassium, sodium, magnesium, and calcium are essential for controlling the function and sensitivity of the muscle and nerve cells.

Most tennis players have knowledge of foods rich in potassium (lentils, spinach, potatoes, fish, meat, bananas, cantaloupe, tomatoes, apricots, etc.), and iron (pork and beef liver, millet, soybeans, wheat germ, lentils, spinach, chocolate, etc.). However, most tennis players are not knowledgeable about sources in our diets for magnesium. The table below lists some good sources of magnesium. Keep in mind, like most tables, each food is listed in mg/100g. Therefore to provide sufficient amounts of magnesium, it is important to eatfoods that may be eaten in larger amounts, such as oatmeal or brown rice as opposed to cocoa powder.