In this study we compared cardiopulmonary responses to upper-body exercise in 12 swimmers, using simulation of the front-crawl arm-pulling action on a computer-interfaced isokinetic swim bench and arm cranking on a modified cycle ergometer. Subjects adopted a prone posture; exercise was initially set at 20 W and subsequently increased by 10 W. min(-1). The tests were performed in a randomised order at the same time of day, within 72 h. The highest (peak) oxygen consumption (VO(2peak)), heart rate (HR(peak)), blood lactate ([la(-)](peak)) and exercise intensity (EI(peak)) were recorded at exhaustion. Mean (SEM) peak responses to simulated swimming were higher than those to arm cranking for VO(2peak) [2.9 (0.2) vs 2.4 (0.1) l x min(-1); P = 0.01], HR(peak) [174 (2) vs 161 (2) beats x min(-1); P = 0.03], and EI(peak) [122 (6) vs 102 (5) W; P = 0.02]. However, there were no significant differences in [la(-)](peak) [9.6 (0.6) vs 8.2 (0.6) mmol x l(-1); P = 0.08]. Thus simulated swimming is the preferred form of dry-land ergometry for the assessment of swimmers.