This is because it recognises that stress management is ultimately brain governed - by weighing up the demands of stress upon the system and allocating energy resources, the brain is in charge of how much we adapt to a training stimulus. (rugbystrengthcoach.com)
The first stage of adrenal activity is called the alarm reaction where the system becomes hyperactive to increase cortisol levels to adapt to the demands of stress. (drjockers.com)
This means that if stress is always high, it «steals» pregnenolone from progesterone to make cortisol in order to meet the demands of stress. (drflannery.com)