Rowing competitions for males are performed over a distance of 2000 m and last 5.8-7.4 min. This time is being improved by 0.01 min per year. Races are most often carried out with an initial spurt in order to increase the total aerobic metabolism. Large individuals have an advantage partly because of a larger anaerobic metabolism, but also because the almost constant weight of the boat, oars and coxswain becomes relatively less for oarsmen with larger body dimensions. Oxygen uptake during rowing increases with velocity to the power 2.4. It is estimated that the metabolic cost of rowing at racing speed corresponds to 6.41 O2 min-1. The most successful oarsmen have a weight of 93 ± 2.6 kg (± s.e.) and a maximal oxygen uptake of 5.9 ± 0.08 1 min-1 (± s.e.). A direct relationship is demonstrated between the average maximal oxygen uptake of the crew (y) and their placing (x) in an international regatta, y=6.15-0.08x (r=0.87). In contrast, measures of muscle strength do not separate the good from less qualified oarsmen except that the best oarsmen can develop a larger force in a simulated rowing position (2000 N). Maximal oxygen uptake is greater during rowing than during running or bicycling, probably because of the intensive involvement of a larger muscle mass. The capacity of the oxygen transporting system is shown to be dependent on the local (muscle) blood flow. Thus metabolic, circulatory and strength measurements indicate that training for rowing should simulate rowing in the boat as much as possible.