Catecholamine levels in fit and nonfit males when exposed to an emotional stress

Abstract

The primary purpose of this investigation was to determine the difference in catecholamine (CA) excretion levels and perceived anxiety levels between physically fit and nonfit human subjects when exposed to an emotional stress. Secondary purposes were to determine the differences in heart rate responses between physically fit and nonfit subjects, as well as the difference in CA excretion levels and perceived anxiety levels between individuals classified as introverts and extraverts. The subjects were 12 college-age male volunteers who were classified as "high" fit (N = 6) or "low" fit (N = 6) according to Åstrand's (1960) age adjusted fitness tables, and classified as introverts (N = 6) or extraverts (N = 4) by The Eysenck Personality Inventory. Two subjects scored at the midpoint of the scale--not being classified as introverts or extraverts. Rock climbing was selected as the experimental stress factor, and subjects were required to have had no previous rock climbing experience. Four three-hour urine samples were collected in order to establish CA excretion levels: baseline, anticipatory, first rock climbing experience, and third rock climbing experience. The Spielberger State Anxiety Inventory (SSAI) was given at each of these four times in order to measure perceived anxiety levels. Pre and post heart rates were recorded for belaying, climbing, and rappelling for the first and third climbing sessions. The results of the analysis for the fit and nonfit classifications indicated significant differences in epinephrine (E) excretion levels and responses on the SSAI between treatments, as well as a significant groups x treatments interaction for norepinephrine (NE) excretion levels. For the dependent variable of heart rate, significant groups x treatments x times and treatments x times x activities interactions were found. Analysis for the introvert and extravert classifications revealed significant differences in NE excretion levels and SSAI responses between treatments, as well as a significant groups x treatments interaction for E excretion levels...