Drafting is the term used in sports physiology and biomechanics to describe the achievement of a more shift and protected position, and can be defined as a technique / strategy in which the competitors are aligned in a group with the aim of reducing the effect of drag force. In this sense, the increasingly common use and successfully effect of the Drafting raised new questions in terms of features and mechanisms that regulate the human displacement in sports such as athletics, cycling, swimming and triathlon, The aim of this study was to evaluate the oxygen consumption during Drafting in swimming using different distances between swimmers and compare this condition with single swimming. Methods: A group of 7 trained male subjects (63.85 ± 9.33 kg, 173.72 ± 6.87 cm; 15.0 ± 0, 81 years; personal record in the 200 meters freestyle = 133.98 ± 4.76 seconds) were evaluated. The swimmers performed the following protocol: i) swam individually two hundred meters freestyle at a constant speed, ii) swam immediately behind a swimmer (0m), iii) swam 3m behind a swimmer, iv) swam 6m behind a swimmer. Swimming in Drafting was performed at the same speed of the first bout. The VO2 was measured by a gas analyzer (K4b2, COSMED, and Italy) coupled to a valve (Aquatrainer, COSMED, and Italy). In data analysis we perform an "averaging" of 10 seconds for every subject, a "smoothing" of 3 points and performed a further filter of the number of breaths per minute (rpm), setting up the ceiling of 55 rpm. Results: With regard to the values of oxygen consumption, the differences between the free swim and swim in different situations of Drafting were not significant and only on condition 0 m there was a decrease in VO2, compared with the single swim. Therefore, our results contradict the current tendency shown in the literature, which seem to indicate a reduction in energy consumption in a state of Drafting. Conclusions: The hydrodynamic drag coefficient of a swimmer that follows behind increases gradually with the distance between the swimmers but this is not matched by an increased oxygen consumption.
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