You only do crunches.
Crunches only target the surface muscles of the abs, leaving the internal and external obliques at rest. It is better to incorporate some planks and wood chops into a regular ab strengthening routine. The larger movements of these exercises use more muscles in your abdomen.An even deeper muscle that affects the appearance of the abs is the transverse abdominus. This very deep muscle helps pull the abdomen inwards. In order to exercise this muscle, incorporate compound movements such as squat presses or dead lifts.
You fail to engage your back.
Your middle back is an important area to focus on when trying to get stellar abs. By strengthening the middle back muscles, you can improve your posture, which will help you to stand tall and show your confidence. By keeping your core engaged during the day, you will look and feel thinner. Try engaging your back muscles for spine-straightening and abs-tightening effects.
You are not building muscle.
If you move too quickly, lifting light weights, you are unlikely to build muscle. In order for muscle to be built for great abs, it is important to lift heavy weights. This decreases the number of reps to six to 12 or until exhaustion. Rest for about one minute between sets.
Learn the pelvic tilt.
When lower back aches during an ab workout, it means you are engaging your lower back muscles, rather than the front of your core. In order to engage your abs, tilt your hips forward so your back remains straight. Many trainers tell clients to imagine they are pushing their belly button into their spine to create a proper form.