Metabolic power and energy cost of mechanical work carried out by a sailor engaged in a solo ocean race: a case study

ABSTRACT The purpose of this case study was to find fundamental information, concerning changes in the metabolic power and energy cost, due to cardio-respiratory and metabolic adaption induced in an aged 52 élite sailor engaged in the solo Atlantic race Onestar from Plymouth (UK) to Newport (USA), in 17 days. While sailing the participant wore an armband device to assess energy expenditure. The sailor also carried out incremental cardiopulmonary tests by a cycle- ergometer just before and after the race. During sailing the metabolic power per body mass unit ranged from 3.4 to 3.9 W kg-1, while the corresponding metabolic cost to transport the body centre of mass inside boat ranged from 14.1 to 35.5 J kg-1 m-1. After race stopped, the cardiopulmonary test showed that, at each step of work load, the oxygen consumption did not reduced with respect to the race beginning. Moreover, the index of aerobic efficiency was 0.23 and approached the theoretic maximum value of 0.25 more than that assessed before the race that was 0.21. It was concluded that several days of very hard sailing can induce specific adaptations in the cardio-respiratory, metabolic and endocrine systems in such a ways of maintaining the previous acquired aerobic capacity, thus generating a physical conditioning aimed at sustaining the high demanding of metabolic power despite occurring higher peak of energy costs.