The Scientific World Journal

Research Article

Changes in Cardiac Tone Regulation with Fatigue after Supra-Maximal Running Exercise

Table 1

Biochemical and heart rate variability parameters measured during the postexercise recovery.
1 min recovery4 min recovery7 min recovery
400 m300 m400 m300 m400 m300 m
Biochemical parameters
 Lactate (Mm) 1 6 . 5 ± 1 . 0 1 4 . 6 ± 1 . 5 ∗ 2 1 . 2 ± 2 . 3 1 6 . 6 ± 1 . 3 ∗ 2 2 . 1 ± 2 . 0 1 6 . 8 ± 1 . 5
 pH 7 . 1 ± 0 . 1 7 . 2 ± 0 . 0 ∗ 7 . 0 ± 0 . 1 7 . 2 ± 0 . 1 ∗ 7 . 0 ± 0 . 1 7 . 2 ± 0 . 1 ∗
  H C O 3 − (Mm) 1 0 . 0 ± 1 . 6 1 3 . 5 ± 1 . 9 ∗ 6 . 5 ± 1 . 1 1 0 . 5 ± 1 . 7 ∗ 5 . 5 ± 1 . 4 1 0 . 0 ± 2 . 2 ∗
 PO2 (mmHg) 1 1 4 . 0 ± 1 2 . 3 1 0 4 . 6 ± 1 7 . 8 1 2 4 . 1 ± 1 4 . 7 1 1 5 . 4 ± 1 4 . 2 1 2 9 . 4 ± 2 0 . 5 1 1 7 . 6 ± 1 0 . 6
 PCO2 (mmHg) 3 2 . 8 ± 3 . 7 3 4 . 8 ± 3 . 5 ∗ 2 4 . 5 ± 5 . 2 2 9 . 1 ± 2 . 6 ∗ 2 3 . 0 ± 3 . 7 2 6 . 9 ± 4 . 0 ∗
 SaO2 (%) 9 5 . 9 ± 1 . 7 9 6 . 0 ± 1 . 7 9 5 . 4 ± 2 . 1 9 6 . 9 ± 1 . 2 9 5 . 8 ± 1 . 7 9 7 . 4 ± 0 . 5
HRV index
 Amplitude(beats.min−1) 7 4 . 3 ± 8 . 0 7 4 . 7 ± 1 0 . 6
 HRRτ(s) 1 8 3 . 7 ± 1 1 . 6 1 3 2 . 1 ± 9 . 8 ∗
 RMSSD(ms) 1 . 8 ± 0 . 0 1 . 8 ± 0 . 1 2 . 4 ± 0 . 2 2 . 1 ± 0 . 4 ∗ 3 . 3 ± 0 . 3 3 . 1 ± 0 . 1
 HF(ms²) 1 1 . 9 ± 2 1 . 9 2 0 . 6 ± 2 0 . 6 1 5 . 3 ± 1 6 . 1 3 3 . 8 ± 2 0 . 7 ∗ 1 3 . 1 ± 1 2 . 6 3 9 . 7 ± 2 7 . 8 ∗
 LF(ms²) 9 . 3 ± 7 . 8 4 9 . 4 ± 3 9 . 3 ∗ 2 4 . 9 ± 3 5 . 9 1 2 1 . 0 ± 1 1 7 . 1 ∗ 1 0 . 7 ± 6 . 2 7 0 . 8 ± 6 1 . 9 ∗
HRRτ was the time constant of heart rate recovery and RMSSD, root mean square of the sum of successive differences between adjacent NN intervals. HF and LF represent high- and low-frequency bands, respectively. *Significant difference was less at P level <0.05.