Abstract
Joint effects of the Type
A behavior pattern and aerobic fitness were examined with regard to heart rate (HR) and blood
pressure (BP) changes elicited by laboratory challenges. Sixty-one college students were
classified as Type A or B using the Structured Interview (SI), and as physically fit or
sedentary using selfreports of activity level and estimated VO
2
max values obtained on a step test. Subjects were challenged with the
SI, presentation of a snake, mental arithmetic, a cold pressor task, and two competitive card
games. Significant A-B differences were found only on the SI and the card games. During the SI:
(a) As displayed significantly greater BP increases than Bs; (b) sedentary subjects showed
greater BP increases than fit subjects; and (c) sedentary As revealed greater BP increases than
either fit As, fit Bs, or sedentary Bs. In contrast, during the competitive games, physically
fit As showed reliably greater BP increases than either sedentary As, sedentary Bs, or fit Bs.
Since the physically fit subjects were almost exclusively varsity athletes and the sedentary
subjects were college students who reported following a sedentary lifestyle, the differences
between sedentary and fit groups may have been due to differences in aerobic fitness or to the
improved ability of competitive athletes or those engaged in fitness training to match arousal
level to task requirements.
