Improving the validity of clinical exercise testing: the relationship between practice and performance.

Abstract

Many studies involving exercise testing fail to address the issue of practice. Those that do vary considerably with respect to the parameters of practice used. We evaluated the effect of two standardized practices on a horizontal submaximal exercise test performed on a treadmill. Healthy men (n = 20) with no previous treadmill exposure were alternately assigned to the experimental (practice) or control (no practice) group. Heart rate (HR), systolic blood pressure (SBP), rate pressure product (RPP), step cadence (CAD) and perceived exertion (PE) were recorded at the end of each work load of the practices and/or tests. We observed no significant differences in these variables over the common work loads for the first practice session in the experimental group and the exercise test in the control group (p greater than 0.05). The two groups were homogeneous with respect to fitness and magnitude of arousal on initial exposure to the treadmill. During the submaximal test, HR, SBP, RPP, CAD, and PE were systematically lower for the experimental group than for the control group. The SBP and RPP were significantly lower in the experimental group (p less than 0.01). The CAD tended toward statistical significance (p less than 0.07), whereas HR and PE were not significantly different for the two groups (p greater than 0.05). When the four common work loads were compared over the two practices and the exercise test for the experimental group, SBP and CAD were significantly higher for practice 1 than for practice 2 and the test (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)