Physiological responses to 90 min of simulated dinghy sailing

Abstract

A dinghy sailing race protocol was developed from video analysis of elite Laser class sailors competing in fairly windy (> 12 knots) national level races. A dinghy sailing ergometer was constructed for use with a 90 min protocol. Subjects watched a video of a Laser dinghy skipper sailing (on‐water) according to the protocol while themselves hiking (leaning out) from the ergometer and simulating their normal on‐water movements in tandem with the video. This simulation was used to examine physiological responses to dinghy sailing and factors correlated with hiking performance in 10 of Australia's top 30 Laser dinghy sailors. Simulated dinghy sailing elicited a large blood pressure response but a low rate of aerobic and anaerobic metabolism. During the 20 min upwind legs, the mean ( ± S.E.M.) systolic and diastolic blood pressures were 172±18 and 100±14 mmHg respectively, and mean arterial blood pressure (MABP) was 123±14 mmHg. Oxygen uptake during the simulated upwind legs was 1.12±0.22 1 min^‐1. Both blood pressure and VO₂ were significantly lower during the 12 min reaching legs. The mean of the blood lactate concentrations measured 1 min following each of the upwind legs was 2.32±0.81 mM. Isometric knee extension strength (at 130°) and the length to which subjects set the hiking strap on the ergometer were moderately related to upwind hiking performance (knee extension strength and upwind hiking strap tension, r=0.62; hiking strap length and upwind righting moment, r=0.66; both P<0.05). Thus, a number of factors, including strength, hiking strap length and cardiovascular fitness, apparently determined righting moment and hiking strap tension during Laser sailing. It is suggested that it is only the discontinuous nature of hiking which allows dinghy sailors to sustain the isometric contractions for extended periods.