Validity of self-reported exercise-induced sweating as a measure of physical activity among patients with coronary artery disease.

Background: In several epidemiological studies, self-reported exercise-induced sweating has been used as a measure of physical activity (PA). Among healthy subjects it is moderately well associated with other measures of PA and physical fitness, but its validity among patients with coronary artery disease (CAD) has not yet been established.

Methods: In a self-administered questionnaire, 233 patients undergoing coronary angiography replied to the question 'In the past 4 weeks, how often have you exercised vigorously enough to work up a sweat?" Patients also gave the frequency and duration of different PA.