Myth 1: You must do abs exercises every day for your abs to show
No, you should not do abs every day. The abdominal muscles are no different from other muscle groups and therefore need at least one day of rest between workouts.
Myth 2: You must do (at least) 100 repetitions to show your abs
There is no need to do 100+ reps to get your abs in shape. Since you would not do 100 pushups or exercises for biceps or shoulders, why would you do 100 and more reps for abs? To obtain the six pack you wish and tone the muscle area you should gradually increase the weight carried, adding more weight on equipment used or using either dumbbells or elastic bands in exercises such as crunches and leg deadlifts.
Myth 3. Doing abs will burn the fat
Doing abs will in no way get rid of the fat in the abdomen area. Just as with other muscle groups, their exercise does not mean that the fat covering them will disappear. The only way to “burn” fat is to increase training intensity thus burning more calories and follow a healthy diet.
Myth 4. Ab exercises hurt the back
The abdominal workout will not worsen your problem (if you have) on your back. On the contrary, the abdominal will help and stabilize the muscles of the waist and back.