To perform V-Ups sit at the end of a bench, place the hands face down under the rear end for leverage, legs should be at 45-90 degree angles from the floor and the upper body at about a 45-90 degree angle from the bench.  Now bring the knees up to the chest while simultaneously bringing the chest towards the knees, repeat.  The legs and torso make a v-shape, thereby receiving the name V-Ups.

V-Ups are as effective for the lower abdominal muscles as any lower abdominal exercise in existence.  But if your goal of performing abdominal exercises is to rid the stomach area of its fat tissue then performing abdominal exercises are a waste of time as abdominal exercises only strengthen, tighten and tone the abdominal muscles.  There is no such thing as spot reducing.  If you desire to lose body fat tissue it is necessary to use a healthy fat burning program to achieve your goal.