Table 2 Effect of physical training on heart rate variability

Older people [14]

Training protocols were subdivided according to their frequency and duration

SDNN 0.721 (0.184–1.257), P = 0.008, I² 41.72%

Hypertensive women [15]

Aerobic and resistance training

SDNN + 54.3%, P < 0.001;

HFnu + 66.8%, P < 0.001;

RMSSD + 37.3%, P < 0.001;

LF/HF  − 68.6%, P < 0.001

Type 2 diabetes mellitus [13]

General training

SDNN 0.59 (0.26–0.93), I² 69.5%;

RMSSD 0.62 (0.28–0.95), I² 60.8%;

LF/HF  − 0.52 ( − 0.79 to  − 0.24), I² 61.1%;

LF -0.37 ( − 0.69 to  − 0.05), I² 78.9%

Endurance

SDNN 0.65 (0.19–1.10), I² 68.4%;

RMSSD 0.66 (0.21–1.11), I² 66.5%;

LF/HF  − 0.49 ( − 0.74 to  − 0.24), I² 18.4%;

LF  − 0.55 ( − 0.95 to  − 0.15), I² 79.6%;

HF  − 0.56 (0.18–0.94), I² 72.8%

Resistance

LF − 0.93 ( − 1.56 to  − 0.3), I² 0%;

LF/HF  − 0.96 ( − 1.59 to  − 0.33), I² 0%

Endurance combined with resistance

–

High-intensity interval training

RMSSD 1.26 (0.78 – 1.94) I² -;

LF/HF − 1.63 ( − 2.64 to  − 0.62), I² 65.2%