No mention of the adrenal glands which sit on top of the kidneys, passively diffusing 80+ hormones through the pumping of the kidneys and movement experienced f

No mention of the adrenal glands which sit on top of the kidneys, passively diffusing 80+ hormones through the pumping of the kidneys and movement experienced from exercise into the blood stream, some of which that last a fraction of a second, where adrenaline helps to shut off part of the immune system. So is this study, observing the effects of the adrenal glands and subsequently released hormones or not?