I recommend you all take DHEA. DHEA is implicated in chronic fatigue syndrome...where melatonin and dhea fail to be produced or fail to be produced at the right time of day.
You will have more energy and your immune system will be stimulated. DHEA is a neurosteroid and low levels can be a result of hormone replacement therapy. I don't know what I'd do without DHEA as I have some degree of adrenal insufficiency. Night and day difference. I recommend EVERYONE take it to prevent neurotransmitter, immune, and premature aging issues. including depression
Also if you exercise you burn dhea hence you feel tired after...one of the reasons aside from electrolyte depletion.