The scissors kick is similar to the common “six inches” but much more dynamic.
Start out lying on your back with your legs out straight. Place your hands under your lower back with palms facing down (to support your back.)
Now you’ll raise your legs and shoulders.
Raise your legs about 3-6 inches off the floor. Then raise your shoulders off the floor and push your elbows into the floor for support. Be sure to keep your abs tight.
The exercise involves taking one leg over the other and “scissoring” your legs. The left leg goes up and to the right while the right leg goes down and to the left. Then the left leg comes back and goes down while the right leg comes back and up. Then scissor your right leg up and to the left, and your left leg down and to the right.
This works your transverse abdominals and really works the thighs, even in ways cycling does not (to keep your legs balanced for a better pedal stroke.)