Lie on your back and bend your knees, placing a Swiss ball across your hips. With your hands on top of the ball and your body crunched forward as demonstrated, push your arms down as hard as possible for six seconds. The harder you push, the more the ball will resist you, giving your abs an intense stimulus. Exhale, relax for a few seconds, and then repeat.
Regular cardiovascular exercise should be an essential part of your plan. I recommend you try and get in three to five cardio workouts per week. If you find you’re not losing as much fat as you’d like then shoot for five sessions a week. If your progress is good then you might be able to get away with just three sessions a week. Adjust appropriately based on your rate of progress.
Why it made the list: This harder version of the Russian twist works the obliques while requiring the upper abs to contract isometrically. To recruit the obliques, you either need lateral flexion (bending to your side), trunk rotation (twisting), or sucking in your belly. Doing your twists works the trunk-rotation function of the muscle, so really focus on the contraction. Try to get a little crunch on either side after the rotation to up the ante.
Elevate your lower body on a low box (preferably padded to protect your knees). This imparts better leverage to your arms and shoulders, an advantage that is especially important for women (usually women are proportionally weaker in the upper body than men). The correct start position is with your shoulders directly over the wheel and your abs pulled in and head down. Keep your shoulders in front of the wheel as long as possible. Inhale while rolling the wheel forward and exhale as you return to the start position. Arching your low back is wrong! This error occurs when the wheel is extended too far for your abdominal strength and performing the exercise like this can cause back injury and pain. You will be able to extend further out, as you get stronger – in fact; I have seen several athletes do this from a standing position!
Do it: Stand with your feet hip-width apart and hold a dumbbell in your right hand, palm facing inwards towards the torso. Keep your back straight, activate your core, and then bend to the side as far as possible—but only at the waist. Hold for one second at the bottom of your range of motion, and return to start for one rep. Do between 12 and 20 reps for one set.
Do it: Think of this as an upside-down dead bug. Start in a tabletop position, with your shoulders over wrists and hips over knees. Engage your core while simultaneously lifting your right arm and left leg. Your foot should be flexed as you kick back, and your palm should face in towards your body. Pause for one second when your arm and leg are at the same height as your torso, and then bring your elbow and knee to touch underneath the body. Repeat on the other side for one rep, and do five reps for one set.