I think the word "exercise" is used a bit loosely in this context and not all exercises are equal. What happened with me was that I tried strength training whil

I think the word "exercise" is used a bit loosely in this context and not all exercises are equal. What happened with me was that I tried strength training while going through a brief, stressful period, and it shot up my cortisol levels and/or caused adrenal fatigue in the worst kind of way : I could not sleep at all and was pacing around the house like a rat in a cage. I suppose I should have done running or cycling instead, which would have calmed me down.