Yoga says.
As a concourse (SANGAM) is a union of three rivers (Ganga, Yamuna and Saraswati). So the Yoga is a union of three energies (Asan, Pranayam and Meditation).
As a bather get himself uplifted by the merit of this auspicious bath, so one who takes the initiative for the above Yoga Program get himself enlightened by this holy act.