Correlation of the break point of the double product and the ventilatory thresholds
Lara-Vargas, Jorge A; Reza-Orozco, Marco A; Pineda-Juárez, José A; Salgado-Solorio, Catalina; Citalán-Jiménez, Antonio; Leyva-Valadez, Eduardo A; Arteaga-Martínez, Rodolfo; Ávalos-Ríos, Javier Miguel
ABSTRACT
Introduction: during physical exercise with incremental load, the double product is increased by sympathetic stimulus, and its increase presents a positive inflection called the double product breaking point or break point of double product (BPDP). Commonly, there is a correlation between this and the lactic threshold (LT), but we do not know its association with the ventilatory thresholds that are usually used to prescribe training.
Objective: to determine the correlation of the BPDP with the ventilatory thresholds.
Material and methods: a descriptive, prospective, analytical, non-randomized study was carried out in which patients with heart disease who underwent maximal cardiopulmonary exercise tests were included. The PD was obtained and plotted as a function of time (every minute) to establish the BPDP by line drawing. The correlation was made with the ventilatory thresholds obtained from the CPET gas analysis using the ventilatory equivalents method.
Results: twenty-one patients between 49 and 59 years old (14.3% women) were studied. The Spearman correlation coefficient was applied, and it was found that there is a strong-moderate positive correlation between BPDP and VAT-DP with statistical significance (p = 0.004, r = 0.60) and in the same way between BPDP and moderate correlation with VT2-DP (p = 0.005, r = 0.59).
Conclusion: determination of PD is a reproducible and easily accessible method for determining ventilatory thresholds. The BPDP correlates with the aerobic-anaerobic ventilatory threshold (VAT), determining training intensity in patients with heart disease.
