In Andy Cutler's book he mentions that severe fatigue after a workout is called an ACTH response. Which means the reverse reaction to exercise, instead of being energized one is wiped out and attributes this to adrenal fatigue. He suggests using coritsol supplementation. Recently, I began cortisol supplementation and take it when going into stressful situations. I am unable to work out still because I am 3 months post amalgam removal and was diagnosed with adrenal fatigue, but the coritsol supplementation has helped me get things done. My doctor and I are following Andy's protocol to start out small (2.5 mgs). So far some days I need just the 2.5 other days need 5.0, and a couple of days needed the 7.5. Only recommended under a doctor's supervision.