According to a Yoga Instructor, These Are the 56 Most Essential Yoga Poses

Sanskrit Name: Navasana

English Translation: Boat Pose

• Begin sitting on your mat. Bend your knees and lift your feet off the floor, balancing on your tush. Keep the spine long and straighten the legs as much as you can without rounding the back. If this is too hard, keep the knees bent — you're still working your core.
• Hold for five complete breaths.

In Ashtanga Yoga, Boat Pose is traditionally repeated five times, with lifts in between each one to really work your abs.