Resumen de Noninvasive Determination of Anaerobic Threshold Based on the Heart Rate Deflection Point in Water Cycling

Stephanie Santana Pinto, Roxana Macedo Brasil, Cristine Lima Alberton, Hector K. Ferreira, Natália C. Bagatini, Joaquín Calatayud, Juan Carlos Colado Sánchez

• This study compared heart rate (HR), oxygen uptake (V[Combining Dot Above]O2), percentage of maximal HR (%HRmax), percentage of maximal V[Combining Dot Above]O2, and cadence (Cad) related to the anaerobic threshold (AT) during a water cycling maximal test between heart rate deflection point (HRDP) and ventilatory (VT) methods. In addition, the correlations between both methods were assessed for all variables. The test was performed by 27 men in a cycle ergometer in an aquatic environment. The protocol started at a Cad of 100 b·min-1 for 3 minutes with subsequent increments of 15 b·min-1 every 2 minutes until exhaustion. A paired two-tailed Student's t-test was used to compare the variables between the HRDP and VT methods. The Pearson product-moment correlation test was used to correlate the same variables determined by the 2 methods. There was no difference in HR (166 ± 13 vs. 166 ± 13 b·min-1), V[Combining Dot Above]O2 (38.56 ± 6.26 vs. 39.18 ± 6.13 ml·kg-1·min-1), %HRmax (89.24 ± 3.84 vs. 89.52 ± 4.29%), V[Combining Dot Above]O2max (70.44 ± 7.99 vs. 71.64 ± 8.32%), and Cad (174 ± 14 b·min-1 vs. 171 ± 8 b·min-1) related to AT between the HRDP and VT methods. Moreover, significant relationships were found between the methods to determine the AT for all variables analyzed (r = 0.57�0.97). The estimation of the HRDP may be a noninvasive and easy method to determine the AT, which could be used to adapt individualized training intensities to practitioners during water cycling classes.