Not only does a well-developed set of abdominals add an aesthetic appeal to a physique unlike any other body part, but your abdominal muscles assist in virtuallyy every movement your body makes both during training and just about every other conceivable activity.
Abdominals should be treated as a major muscle group. They should not be trained as an afterthought at the end of a workout. They should be methodically trained as you would train your chest, back, legs, etc. It’s important to view your abs in the same manner as you do the fore mentioned muscle groups and apply the same intensity principles.
Like calves, but much more so, your abdominals are called upon for their strength all the time. From sitting to standing to running, your abs assist and help power each of these activities. When you lie down you use your abs. When you get up you use your abs. When laugh, sneeze, cough, burp, you name it, you use your abdominal muscles.
It’s very important to have well-developed and strong abdominals
A strong set of abdominals will help protect you from many common weight training injuries. In fact, most lower back injuries are due in part to weak abdominals. I would venture to say that 50 percent of all lower back injuries are related to underdeveloped and weak adbominals.
I recommend training abdominals once and sometimes twice weekly. And your abs can be trained with the Max-OT training principles. Understand that your abs are muscles and should be developed through overload.