On this auspicious day of Rathasapthami, also called Surya Jayanthi, the Sun is believed to transmit high positive energy. Offering Sun Salutations (or Surya Namaskar) to Surya Narayana (Sun god) on this day is a way for the human body to energetically and consciously receive this positive energy. As a result, each cell of the human body becomes more powerful to fight any disease.
