ENGLISH VERSION dium, and maybe due to the fact of this trend is relatively recent, procedures for prescription and load control of aquatic activities which can be applied to health clubs routine, especially for aerobic activities developed in aquatic bicycle, are still scarce.In the trial to present a simple method for identification of the anaerobic threshold (Lan), Conconi et al. (6) , presented a continuous running protocol with growing velocity in which the heart rate (HR), represented in Cartesian axis, presented a linear initial phase followed by a second curvilinear one. The authors verified that the transition point between these phases called cardiac deflexion point (HRDP), corresponded to the Lan. From its release on, the Conconi test has been successfully applied to different activities such as: swimming, canoeing, skiing, cycling, skating, rowing and athletic marching (7)(8) . In the conventional cycle ergometer, the developed power is a product of the velocity (circumference x wheel rotation) by the resistive load applied over the wheel. On the aquatic bicycle, since the resistance is imposed by the water resistance, the workload manipulation occurs by alterations in the pedal rotation (RPM). Once the water resistance is proportional to the wheel velocity (in the aquatic bicycle, with paddles), the increase in RPM causes both increase in wheel velocity and resistance applied over it. Martins and Lima (9) used a protocol with increases of 10 RPM, at every 2 min. and observed that the HR curve, after an initial phase relatively linear with increases of approximately 23 BPM at each stage, presented in higher loads a tendency to curvilinear behavior similar to the one proposed by Conconi et al. (6) . The findings by Martins and Lima (9) , who observed a HR nonlinear behavior in aquatic bicycle point to the possibility of HRDP identification in this kind of ergometer, as proposed by Conconi et al. (6) . Considering the need to reach simple aerobic exercise prescription method which is able to be applied in practical situations, the aim of the study was to adapt the Conconi et al. test (6) for identification of the HRDP in aquatic bicycle.
METHODOLOGYSubjects -27 subjects were evaluated (24 ± 6 years, 171 ± 8 cm, 66 ± 12 kg): 15 males and 12 females. All individuals signed a consent form for studies involving humans. After weight and height measurements, all participants were submitted to the progressive test, performed in a swimming pool at least 1.2 m deep and water temperature ranging from 25 to 28 o C.Aquatic bicycle -the test was performed in an aquatic bicycle HIDROCYCLE ® brand name. The used model had seat height regulation in relation to the pool bottom, so that it was possible for all individuals to perform the test with water at the umbilical scar level.Pilot study -In the study by Martins and Lima (9) , with increment of 10 RPM at every 2 min., HR increase of approximately 23 BPM was observed. Conconi et al. (10) suggest that, for identification of the HRDP, the HR increases are not ...