My amount of the catabolic hormone cortisol decreased. As cortisol competes with testosterone and intensifies muscle breakdown, keeping it at a lower level boosts up your Testosterone Booster. That permits your muscle to achieve maximum growth and strength. But don't just take my word for the program! A Brazilian research showed an almost immediate decline in blood cortisol levels by people who has been given a sole doze of zinc. Another study conducted by Justus Liebig University (Germany) indicated low variety of cortisol amongst athletes who took a magnesium supplement.