The cardiopulmonary response to 1-minute incremental cycle exercise in a population of 77 sedentary middle-aged men provides an opportunity to develop typical values that may prove useful in assessing impairment and disease. Maximal oxygen uptake can be predicted from age and height, using standard predicting formulas. Patterns of change in ventilation, anaerobic threshold, heart rate, oxygen pulse, and arterial blood gases during exercise are similar to those previously reported, although the magnitude of changes may be different.