A standard bicycle ergometer test was performed on 60 male volunteers at the Canadian National Exhibition. Most were drawn from Toronto and its environs, and "white-collar" workers predominated. Ages ranged from 19 to 61 years. The Astrand nomogram was used to predict the oxygen uptake of the 45 subjects with a normal resting pulse rate. The older subjects had a lower oxygen uptake than Scandinavian office workers, particularly relative to body weight. This conclusion is subject to the limitations of a non-random sample, but seems independent of the professional-class bias. Almost all subjects exceeded the "ideal" body weight. Working capacity was 20% greater in subjects taking regular exercise than in those who were inactive.