The aim of the present study was to develop a snorkel (SNK) with low cost for cardio respiratory parameters measurement in swimming. So, a mask of gas analyzer VO2000 (MASK) was adapted to a SNQ developed by man craftwork form with dead space of 250 ml. Eight subjects were submitted to two incremental tests (IT) on cycloergometer using the MASK and the SNK. The IT(s) occurred until voluntary exhaustion and it was composed per stages of 3 min and with initial load and grade increment of 35 W. In both situations, gaseous samples were collected in intervals of 10 s for determination of the amount of oxygen (VO2), of carbonic gas (VCO2) and of ventilatory volume (VE); heart rate (HR) measurement was done with monitor frequency heart (Polar). The comparison of the cardiorespiratory parameters (VO2, VE, VCO2) and HR measured with a SNK and a MASK was performed with the Student's t test of dependent samples, while the Pearson's correlation test and graphic analyzer of Bland and Altman were performed to verify the associations and agreement among parameters. In all cases the level of significance was P < 0.05. The appropriate equations of the correction of values originating from SNK was verified by systematic error (bias), aleatory (precision) and accuracy (ac). It was not found significant differences among the values of VO2, VCO2 and HR obtained with the MASK and SNK. The values of VE measured with SNK were found significantly higher than the obtained with the MASK. However, all parameters presented high agreement and correlation (0.88 to 0.97). Besides, low values of bias (VO2 = 0.11 L/min; VE = 4.11 L/min; VCO2 = 0.54 L/min; 8.87 bpm), precision (VO2 = 0,24 L/min; VE = 11.02 L/min; VCO2 = 0,18 L/min; 7.42 bpm) and accuracy (VO2 = 0,27 L/min; VE = 11.76 L/min; VCO2 = 0.56 L/min; 11.56 bpm) were verified. Thereby, we could conclude that the SNK developed in this study allow a validate measurement of cardiorespiratory parameters in swimming.
Swimming; Snorkel; Oxygen uptake; Ventilatory volume; Heart rate
