In order to keep the inner goodness and mind’s total attention, mantras are repeated said by the Hindu devotees on the auspicious days of Ekadashi. Devotees also indulge in saying ‘Om Namo Bhagavate Vaasudevaaya’ which is a powerful Vishnu mantra. They try chanting this particular mantra for the whole day from early morning to mid-night.
According to the Hindu religious scholars and pundits, Lord Krishna and Lord Vishnu are the same so devotees also say or chant ‘Hare Krishna mantra’.
On the other hand, a powerful mantra that can be chanted with meditative attention on different areas of the body are ‘Om Damodaraya Namah’ for Lotus Feet, ‘Om Madhavaya Namah’ for Thighs, ‘Om Kamapataye Namah’ for Private Parts, ‘Om Vamanaya Namah’ for hips, ‘Om Padmanabhaya Namah’ for Navel, ‘Om Vishvamutaye Namah’ for Stomach, ‘Om Jnanagamyaya Namah’ for Heart, ‘Om Srikanthaya Namah’ for Throat, ‘Om Sahasrabahave Namah’ for Arms, ‘Om Paramayogine Namah’ for Lotus Eyes, ‘Om Urugayai Namah’ for Forehead, ‘Om Narakeshvaraya Namah’ for Nose, ‘Om Sarvakamadaya Namah’ for Hair and ‘Om Sahasrashirshaya Namah’ for head.
In the Sanskrit language, the word for fasting is “Upa-Vaas” that means staying very close to God. Devoting one day to introspection and deviation from the normal lifestyle is the original concept of fasting and chanting mantras wholeheartedly with great devotion and dedication on the auspicious day of Ekadashi.
There are many mantras related to Lord Vishnu that can be chanted or repeated on the days of Ekadashi. These mantras can be by-hearted or read from the text to a large extend in order to please the Lord.
‘Vishnu Sahasranama Stotram’, ‘Vishnu Ashtottaram’, Achyuthashtakam, Sri Krishnashtakam, Damodara Ashtakam, Sri Rama Raksha Stotram, etc are also chanted on Ekadashi.