In the Indian context, Upavasa is of immense importance. Fasting or abstinence from food is a part of Upavasa. Upavasa is much deeper term and involves living in association with Guru, God or Agni. Our mind generally is pulled towards the objects of the senses — sight, hearing, taste, touch and smell. An outward going mind is unable to perceive subtler aspects of life. And hence to make the mind perceive subtler aspects, the objects of the senses have to be temporarily taken away so that the mind is cleansed and clarity of mind dawns. Vrata is generally combined with Upavasa and is observed during important festivals, ceremonies (like marriage) and towards specific divinities. Vrata is a vow or a promise to oneself.
In the Vana parva of the Mahabharat, Arjuna was on a pilgrimage to the northern part of India. It is said that inorder to gain immense power, strength and blessings of the Gods, he undertook severe austerities. He ate withered leaves and passed the first month eating fruits once in 3 nights. The second month, he ate once in 6 nights and the third month by eating once in every 15 days. He went on complete fasting, consuming only air, since the fourth month. He stood with arms raised, leaning upon nothing and on his toes and performed penance. The amount of courage and clarity that Arjuna got after undertaking such a penance is immeasurable.