Maximal aerobic power and related variables during submaximal work were determined on the bicycle and on the rowing ergometer in 9 oarsmen and in 9 control subjects. During submaximal work, heart rate and pulmonary ventilation were similar with the two exercise procedures in each group, but the oarsmen had lower values than the control subjects. Oxygen uptake at a given workload was higher on the rowing ergometer than on the bicycle ergometer for both the oarsmen and the control subjects. During maximal exercise, the control subjects reached significantly lower values on the rowing ergometer than on the bicycle ergometer for maximal oxygen uptake and maximal oxygen pulse. The oarsmen however attained practically the same values on the two ergometers, with a rank difference correlation coefficient of 0.94. The difference between the results obtained in control subjects and in oarsmen supports the concept of training specificity.