Lie on your back with your legs bent and feet flat on the floor.
Your knees and feet should be hips distance apart.
Tighten your buttock and abdominal muscles and lift your hips up into a bridge.
Keeping your hips level and high, raise your heels off the floor a little.
Straighten one leg out in front of you so that it is in line with the rest of your body.
Next, rapidly kick the other leg out in front of you whilst simultaneously bringing your first foot back to the floor.
Continue alternating legs for a count of 3, and then hold.
1-2-3-hold.
1-2-3-hold.
Continue.