The sport scientist's understanding of the biomechanics and physiology of sailing, together with its application to nutrition, training and injury prevention in the elite competitor, has continued to develop over the past decade. Very large mechanical forces are imposed in the vertical axis of the body, which give rise to frequent complaints to low back and knee pain and, occasionally, even to muscle rupture. Training programmes should emphasise the development of isometric endurance in the relevant muscle groups, such preparation continuing throughout the winter months. The oxygen cost of sailing is relatively light, and development of aerobic fitness should be advocated for reasons of general health rather than competitive success. Because of the intense muscle contractions that are developed during competition, heart rates and blood pressures are high in relation to oxygen consumption. However, during normal sailing, tacking and fluctuations of wind speed limit the development of muscle fatigue. In contrast to the operation of small craft, the crew of large ocean-going vessels may have a very high daily energy expenditure, probably related to difficulty in relaxing at any point of day or night. Windsurfers face similar physiological demands to the dinghy sailor and they also have frequent complaints of back pain. Knowledge of the relevant health issues remains limited, even among elite competitors, and there remains substantial scope for increased education of team members.