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 (V˙O2peak), heart rate (HRpeak), blood lactate ([la−]peak) and exercise intensity (EIpeak) were recorded at exhaustion. Mean (SEM) peak responses to simulated swimming were higher than those to arm cranking for V˙O2peak [2.9 (0.2) vs 2.4 (0.1) l · min−1; P = 0.01], HRpeak [174 (2) vs 161 (2) beats · min−1; P = 0.03], and EIpeak [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 · l−1; P = 0.08]. Thus simulated swimming is the preferred form of dry-land ergometry for the assessment of swimmers.