In this video, Alex is demonstrating how to perform a Straight Leg Raise.
Lying on your exercise surface, bend your opposite knee up (leg not performing the exercise), placing that foot flat
Flex your foot, pointing your toes toward the ceiling on the leg to perform the exercise
Tighten the muscles on the top of the thigh
Keeping the knee straight, slowly lift the leg up 8-10 inches, not raising any higher than the opposite knee
While lifting the leg during this exercise, always make sure the knee remains straight as well as keeping the stomach muscles firm, not allowing your back to arch off of the exercise surface