It is good to retain the youth both in the body and the mind.  This is the desire of most of the people all over the world. There are special asanas and allied activities, which help a being to perform greater work with the body and mind until a very old age. One feels energetic and cheerful.  There are asanas and pranayama and some other disciplines specific for retention of youthful looks and explicit for this purpose.   These asanas assist in strengthening of body muscles, nerves and toning the skin and keeping the wrinkles away well past the prime of youth.   One can retain strength and a good figure for a very long time. These asana etc are not discussed here, as they are specific for each individual depending on tattva predominance, texture and tone of the skin, age and many other factors.    Since they can only be practiced under supervision with strict diet control it is no use discussing them here, as wrong performance may not get the desired results.