Bicycle Crunches
Lie on your back with your hands (unclasped) behind your head and your knees bent. Engage your abs while lifting your upper back and shoulders off the ground. Now, move your right elbow towards your left knee so that they meet in the middle of your body. Next, switch your position so that you bring your left elbow to meet your right kneeKnee Drop
source: us.myprotein.com
Lie down with your abs engaged and back flat to the floor. Lift your legs into a table top position, with your calves parallel to the floor and knees aligned over your hips. Squeeze your legs together to engage your inner thigh muscles and lower abs. Drop your knees slowly to your right, keeping your abs tight and back flat to the floor. Exhale to bring your knees back to centre, and inhale to drop them to the other side.
Plank Up-Downs
source: symmetry4me.com
Get into the plank position, keeping your arms directly beneath your shoulders, your bum tight and your abs engaged. Lower one arm down onto your forearm, and then follow it down with the other arm. Move back up to the plank position, one arm at a time. Keep your core tight throughout and avoid rocking your hips.
Read More: