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

Summary Objective To compare ventilatory threshold (VT) and heart rate variability threshold (HRVT) in normal weight (NW: 22.75 ± 1.66 kg/m 2 ), 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 (HRVT SD1 ) and RMSSD (HRVT RMSSD ) lower than 3 ms and with a visual deflection in the curve of intensity versus SD1 (HRVT SD1-v ) and RMSSD (HRVT RMSSD-v ) indexes. Results The HRVT SD1 , HRVT SD1-V and HRVT RMSSD-V were identified in 100% of individuals and the HRVT RMSSD 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 VO 2 (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 VO 2 ( r : 0.38 – 0.62), there was a good agreement between them, mainly HRVT SD1 . Conclusion The criteria and indexes of determination of VT by HRV, especially the HRVT SD1 , can be used, in overweight and obese young people in the evaluation of aerobic fitness and in exercise prescription for this population.