“…Instead of measuring catecholamines in the blood, investigators are increasingly measuring cumulative levels of free epinephrine and norepinephrine in the urine, using 15-hr and 24-hr cumulative samples (Baum & Grunberg, 1997; Janicki-Deverts, Zilles, S. Cohen, & Baum, 2006). Urinary measures of epinephrine have been most closely linked to cumulative psychological stress and anticipation of threat (see Baum, Lundberg, Gruenberg, Singer, & Gatchell, 1985; Dimsdale & Moss, 1980). In contrast, urinary measures of norepinephrine do not appear to be as strongly coupled with stress, likely due to the confounding effects of norepinephrine’s sensitivity to changes in physical activity (Rogers et al, 1991), and the constant slow release of norepinephrine from sympathetic nerve fibers into circulation, among other factors (for reviews, see Steptoe, 1987; Weiner, 1992).…”