Five Ab Exercises To Warm Up

If you want to take your workouts to the next level, start with your middle. Your core contracts first in every exercise and then the energy is transferred to the limbs.  In order to prime your core muscles, so they fire better during your other workout, you need to train your core first. By training your torso when your muscles are fresh, you will achieve the fastest gains.
Performing classic ab moves like crunches and knee-ins at the beginning of your workout to warm up the muscles, you will be able to lift more weights, work more muscle and burn more calories later on.
Sharing four ab warm-up exercises that you can do on a bench.

Elevated Bicycle Crunch

Lie on the bench with face up, place your hands by your ears. Keep your legs out straight and elevated. Bring one knee up as you bring the opposite elbow to touch that knee. Contract your abs tightly as you come up with an exhale. Alternate with the other side. Alternating shoulder to knee crunches work all the major ab muscles but focus more on the obliques.
Muscle worked:  obliques & lower abdominals

Fifer Scissor

Lie flat on your back with arms by your side and legs straight. Lift your left leg in the air so that your foot is directly above your hip. Lift your right leg one inch off the bench. Switch legs simultaneously so now the right leg is above hip and the left leg is above the bench.
Muscle worked:  hip flexors & the transverse abdominis

Knee in

Sit with your legs bent and feet slightly raised off the bench. Find a balanced position with your hands grabbing the bench. Stretch your legs slightly and at the same time bend body backwards into a reclining position. With a greater contraction of the ab muscles, bring the knees closer to chest while returning to the original position.
Muscle worked: lower abdominals

Reverse crunch

Lie faceup with lower back pressed into the bench with your hands grabbing the bench. Lift your legs and drive your thighs up to your chest. In the top position, rotate your hips upward and then Lower to the bench and repeat.
Muscle worked: lower abdominis & intercostals

Side Plank

Place your legs on the bench, either stacked or staggered for more stability. Lay on your side with your forearm flat on the floor, bottom elbow lined up directly under your shoulder. Form a straight line from your head to your feet. Hold for 15 to 30 seconds. Your top hand can be on side of hip (easier) or reaching up to the ceiling (harder).
Muslce worked: transversus abdominis, rectus abdominis, obliques & quadratus lumborum