Exercise impacts cortisol levels. Over-exercising can wreak havoc on the sympatho-adrenal system. A story of an ultra-marathoner using cortisol to self-medicate is a good example of this. Nickademus de la Rosa He had a troubled childhood, and for this reason likely had low cortisol during adolescence.He became one of the most accomplished ultramarathoners at the age of 19. After 10 yrs of elite competition and prizes, he was diagnosed with bipolar personality disorder.