Heart rate variability estimates ventilatory threshold regardless body mass index in young people

Abstract

Summary Objective To compare ventilatory threshold (VT) and heart rate variability threshold (HRVT) in normal weight (NW: 22.75 ± 1.66 kg/m2), overweight (Ov: 27.03 ± 1.48) and obese (O: 33.26 ± 2.39) young people (21.46 ± 2.06 years old). Methods The HRVT was determined at the first intensity with a SD1 index (HRVTSD1) and RMSSD (HRVTRMSSD) lower than 3 ms and with a visual deflection in the curve of intensity versus SD1 (HRVTSD1-v) and RMSSD (HRVTRMSSD-v) indexes. Results The HRVTSD1, HRVTSD1-V and HRVTRMSSD-V were identified in 100% of individuals and the HRVTRMSSD in 90.32%. The VT was identified at similar workloads (NW: 109.50 ± 36.09; Ov: 90.00 ± 16.20; O: 96.00 ± 25.69 W) and VO2 (NW: 20.52 ± 6.01; Ov; 18.01 ± 4.35; O: 15.14 ± 2.45 mL/kg/min), no differences (P > 0.05) among the HRVT and groups. Despite the correlations between VT and the diverse HRVT were from low to moderate for workload (r: 0.25 – 0.42) and VO2 (r: 0.38 – 0.62), there was a good agreement between them, mainly HRVTSD1. Conclusion The criteria and indexes of determination of VT by HRV, especially the HRVTSD1, can be used, in overweight and obese young people in the evaluation of aerobic fitness and in exercise prescription for this population.