Developing a well-defined abdominal profile is challenging. While clean diet, cardio, and genetics play important roles, many factors must be in balance for a well-sculpted set of abs to emerge. Yet, the impact of one important factor, namely, cortisol, is usually underestimated. Cortisol has an important role to play in abdominal (visceral) obesity. Here's how.
Cortisol, a steroid hormone of the adrenal glands, performs two important functions in the body. The first is energy regulation via selection of appropriate macro-nutrients for the body's needs. The second is energy metabolization via relocation of triglycerides (body's fat stores) to satisfy energy demand by needy tissues like working muscles.
Under stressful conditions, more cortisol than normal is secreted. Before this stage, the body would have released norepinephrine (noradrenaline), epinephrine (adrenaline), and then cortisol. If this is temporary, no damage is created. If stress conditions are sustained, however, cortisol ensures 1) that adipocyte cells (young fat cells) grow into mature ones, and 2) that adipocyte stores are relocated to fat cell deposits deep in the abdomen.
So, under stressful conditions, cortisol directly affects fat storage and weight gain. Tissue concentration of cortisol is regulated by an enzyme, located in adipose tissues, that converts inactive cortisone to active cortisol. The higher the amount of this enzyme in the deep fat cells surrounding the abdomen, the higher the amount of cortisol produced at the tissue level. Furthermore, deep abdominal adipose cells have much greater blood flow and much more cortisol receptors compared to subcutaneous fat cells. This influences cortisol's capacity to accumulate fat and enlarge the size of fat cells.
To summarize, any programme of abs-sculpting should not ignore the role of cortisol in reaching the desired result.