Invigoration, together with well-balanced diet and proper exercise, is very important to lead a long life in good health and prevent diseases.
   There are medicinal dishes good for middle-aged or elderly people to strengthen vigour, and for weak ones to restore health and enhance resistance to disease.
   Traditional medicinal stuffs include insam, astragalus, fruit of matrimony vine, pine nuts, yam, tuckahoe, honey, foxglove, Angelica gigas, Cnidium officinale, Solomon's seal, chrysanthemum, sesame and walnut.
   They are cooked with cereals, meats, fish, eggs, vegetables and other ingredients.
   Foods for invigoration should be prepared to soften the medicinal properties of the cooking materials and taken for a long period.
   The medicinal ingredients, no matter how excellent they are, cannot produce remarkable effects in a little span of time; instead, excessive use of them may produce negative effects in controlling overall functions of body.
   Therefore, it is necessary to set correct cooking methods and dosage, increase their portion, while paying attention to digestion, and vary dishes according to the health conditions.