Dr. Stacy Sims: Female-Specific Exercise & Nutrition for Health, Performance & Longevity

623.324 - 647.635 Dr. Stacy Sims

And so when we're talking about overall stress, we're talking about cortisol increase, and they can't hit intensities high enough with no fuel to be able to invoke the post-exercise responses of growth hormone and testosterone, which then drop cortisol. So from an overall stress perspective, that fasted workout and holding that fast for a long period of time increases cortisol.