Variations in cardiovascular response accompanying differences in arm-cranking rate

Arm ergometry may be the only means of exercise testing for persons who cannot perform treadmill or bicycle ergometer testing. To determine the effects of arm-cranking rate on cardiovascular responses, ten healthy college students underwent maximal graded exercise testing on the arm ergometer. Each subject completed randomly ordered tests using 30-, 60-, and 70-rpm cranking rates at least seven days apart. Analysis of variance (ANOVA) indicated that both peak heart rate (HR) and rate pressure product (RPP) increased significantly with increases in cranking rate across the three tests (p less than .05). Peak systolic blood pressure (SBP) and oxygen uptake (VO2) for the 60- and 70- rpm tests was significantly higher than for the 30-rpm test (p less than .05). Peak work rate (WR) was significantly higher for the 70-rpm than for the 30-rpm test (p less than .05). Because RPP is an accepted index of myocardial oxygen consumption, the results indicated that the metabolic load on the heart was increased by increments in the cranking rate. The increases in RPP occurred as a function of the combined increases in HR and SBP as rpm increased from 60 to 70. Since increases in WR and VO2 did not occur as rpm increased from 60 to 70, the rise in HR and RPP may have occurred in response to factors other than the total-body oxygen demand.