This 12-minute ab workout doesn't include crunches

1. 30-second single-arm sit-ups Start by lying on your back with your lower back pressed into the floor and your legs extended away from you; this is the starting position for a single-arm sit-up.

Raise a dumbbell above your head while holding it with one hand. Keep your arm outstretched and your core engaged as you lift your head, neck, and torso off the mat.

Your arm holding the dumbbell should be extended above your head as you sit tall at the top of the exercise. Maintaining a tight core, slowly and deliberately return to the beginning posture.

2. One-minute pull-through drive Stack your wrists under your shoulders, tighten your core, and hold a dumbbell at your side to begin this exercise in a high plank posture. Grab the dumbbell with your opposite hand from beneath your chest,

and then lift it and move it to the other side of the mat. Then switch hands and do it again. Following your second pull-through, perform two sets of mountain climbers by bringing your knee to your opposite elbow.


3. Dead bug pullover: 1 minute To perform this move, lie on your back with your legs bent and your arms extended above your head, gripping a dumbbell in each hand. Lower the dumbbell to the floor,

but don't let it touch the ground; do this by extending one leg away from the body and both arms behind the head. Reverse the motion while keeping your abs tight to return to the starting posture. Extend the other leg away from you and repeat the exercise.

 Keep alternating legs for a full minute, keeping your lower back flat on the floor the whole time.

4. Side plank reach: 30 seconds per side To perform this exercise, go into an elbow-supported side plank posture while keeping your hips and legs straight and your core tight. Put the bottom leg on the floor if that's too much of a challenge.

Raise a dumbbell above your head and hold it there. To perform this exercise, twirl the dumbbell under your body and then back above your head while engaging your core. For the whole 30 seconds, maintain this twisting motion before reversing sides.