Sit-ups tighten and tone the abdominal muscles that run from beneath the sternum to above the pelvis. This results in a flatter stomach and, if practised along with plenty of aerobic exercise ...

Sit-ups require you to lift all the way up ... like your triceps and shoulders, while you hold the pose. Still, all of these ab exercises can be part of a healthy, effective workout regimen.

Place your hands by your temples, with your elbows pointing out to the side. Lift your left knee, and at the same time, bend ...