Dingy sailing has traditionally been thought of as a static sport, with hiking, involving considerable . isometric muscle action in the quadriceps and to a lesser extent the abdominal muscle groups, the major physiological challenge. Relatively high heart rates (HR) have been reported in on-water studies, but as these were often mirrored with low values for oxygen consumption, little importance has been placed on .-«: aerobic training. Low oxygen consumption rvo 2) during isometric exercise is well documented, but"if . the action is purely isometric, the elevated heart rates are difficult to explain. This thesis set out to investigate the physiological demands of elite single-handed dinghy racing by using a combination of onwater measures and simulations in the laboratory using sports specific sailing ergometers. The end goals were to establish the physical demands of the sport and the anthropometric and physiological characteristics required for success at the elite level, and offer appropriate assessment and training regimens. This work is aimed at changing practice based on scientific evidence rather than on belief. On-water data, reported in chapter 4, was unanimous in establishing that the physical demands increased as wind speed increased and that upwind sailing was more strenuous than downwind sailing. Heart rates and blood lactates (Labl) averaged 84% HRmax and 4.64 mmol.l" and 78% HRmaxand 3.53 mmol.l" for Laser and Finn sailing in strong (9-15 m.s") and moderate winds (5-9 m.s") respectively. It has been suggested the elevated heart rates are caused by the isometric contractions involved with hiking, and is a misleading indicator of the overall energy demands. Chapter 5 investigated the physiological responses to a static 30 minute laboratory simulation of hiking. Blood pressure (BP) was markedly elevated peaking at 166/95 mmHg and hyperventilation was evident. But in spite of significant muscular discomfort, with rates of perceived exertion peaking at 15.3, HR and vo 2 remained low and peaked at 101 ± 9 beats.min" and 7.1 ml.kg'i.min" respectively. These results replicate the responses of isometric exercise reported in the sailing literature, and suggest that other mechanisms are responsible for the elevated values reported on the water. Chapter 6 describes 30 minutes of simulated upwind sailing, on a purpose built Laser sailing ergometer, and was designed to mimic the dynamic movements of competitive sport. The main findings saw mean HRpwof160 beats.min" (87.4% Hrmax), a mean V02 of32.2 ± 3.0 ml.kg'l.min" (58.1% V02max),final L~I of 4.47 ± 0.23 mmol.l", Ventilatory equivalents for oxygen were higher than those obtained during a maximal cycle ergometer test, providing evidence of hyperventilation. This hyperventilation may indicate that even a dynamic simulation of single-handed sailing has an underpinning isometric contraction of the quadriceps and/or abdominals on which are superimposed a range of dynamic movements that typifies elite sailing. These results have been confirmed in a recent on-water study of elite French Laser sailors (Castagna and Brisswalter, 2004) when peak values of78.5% HRmaxand 68.4% vo 2max after 30 minutes of hiking were reported. It is argued that these elevated values indicate that the sport has elements of both aerobic and anaerobic metabolism. However, it seems that the competence level of the sailor and the duration of the hiking action are important factors considered. The main findings reported in this thesis show that elite single-handed dinghy sailing is not a static sport as the majority of the previous scientific literature suggests, and oxygen uptake is taxed considerably. Thus, relevant aerobic training to facilitate both recovery and to underpin the dynamic activities of sailing are warranted as part of a training regimen. A sport-specific assessment of the sailors' physical characteristics by a coach and applied sports scientist with knowledge of the physiological demands of competitive single-handed dinghy sailing, together with an appropriate battery of fitness tests and a combination of aerobic and anaerobic training exercises would allow the sailors' physiological strengths and weaknesses to be evaluated. Based on this information data-base appropriate training programmes can be introduced that maximise sailing performance.