Arjuna penance

1. (the first) month subsisting on fruit and roots. 
2. I spent the second month, subsisting on water. 
3. in the third month I totally abstained from food. And 
4. in the fourth month I remained with upraised arms. And a wonder it is that I did not lose any strength.

http://www.sacred-texts.com/hin/m03/m03166.htm