Is There Agreement and Precision between Heart Rate Variability, Ventilatory, and Lactate Thresholds in Healthy Adults?

Figure 1. Represents an example of threshold identifications 1 and 2 on the CPxS (single participant). (A) represents the lactate threshold 1 and 2 (black line) and heart rate variability thresholds 1 and 2 (gray line). (B) represents the ventilatory threshold 1 and 2 (dark gray and black lines) and heart rate variability thresholds 1 and 2 (light gray line). Lactate thresholds 1 and 2 (LT1 and LT2), ventilatory thresholds 1 and 2 (VT1 and VT2), and heart rate variability thresholds 1 and 2 (HRVT1 and HRVT2).

Figure 2. Bland Altman plots for speed at thresholds 1 (A–C) and 2 (D–F). The dashed lines at the ends represent the limits of agreement (1.96 SD) and the dashed central lines (bias). Lactate threshold 1 (LT1), ventilatory threshold 1 (VT1), heart rate variability threshold 1 (HRVT1), lactate threshold 2 (LT2), ventilatory threshold 2 (VT2), heart rate variability threshold 2 (HRVT2).

Figure 3. Bland Altman plots for V̇O2 at thresholds 1 (A–C) and 2 (D–F). The dashed lines at the ends represent the limits of agreement (1.96 SD) and the dashed central lines (bias). Lactate threshold 1 (LT1), ventilatory threshold 1 (VT1), heart rate variability threshold 1 (HRVT1), lactate threshold 2 (LT2), ventilatory threshold 2 (VT2), heart rate variability threshold 2 (HRVT2).

Figure 4. Bland Altman plots for HR at thresholds 1 (A–C) and 2 (D–F). The dashed lines at the ends represent the limits of agreement (1.96 SD) and the dashed central lines (bias). Lactate threshold 1 (LT1), ventilatory threshold 1 (VT1), heart rate variability threshold 1 (HRVT1), lactate threshold 2 (LT2), ventilatory threshold 2 (VT2), heart rate variability threshold 2 (HRVT2).