Okonkwo has also shown that individuals who work out have greater brain quantity in areas of the mind associated with thinking as well as executive function. Also if you're not starving right now, you might want to consider having a snack to prevent being starving within the two-hour window before you work out. Scientists at UCLA found that subjects that exercised with partially absorbed food in their stomachs experienced as much as a 54 percent reduction in development hormone production. Topics who were fed purely carbohydrates prior to an exercise still experienced lower production of growth hormone by as much as 24 percent.