Just curious as to what Lisa or Sean's thoughts are on constant HIIT sessions and adrenal fatigue. Especially with some of the longer sessions going closer to 40 minutes and doing them 5-6 times per week, could this be overkill or potentially cause serious adrenal issues? Have any of you guys had problems with this? Of course I know rest days are crucial but I thought I read somewhere (sorry, can't remember where exactly) that HIIT sessions should not be longer than 20 minutes due to this reason.