Respiratory Sinus Arrhythmia

Respiratory Sinus Arrhythmia (RSA) is a natural phenomenon that gives an accurate indication of health and fitness. It is more noticeable in young, fit, and healthy, but tends to decline with old age and ill-health. It is as well a high-quality sign of strain levels. Heart Rate Variability (HRV) is also an indication of health … Read more