Ahead, doctors explain how to identify a dangerous heart rate vs. a normal one. , director of Women’s Translational Cardiovascular Research at the Emory Women’s Heart Center and member of the Women’s Heart Alliance Scientific Advisory Board. Some common causes of a low heart rate are athletic conditioning, certain medications like beta blockers, or infections, Mamdani says. Below, cardiologists explain what constitutes a normal heart rate vs. a dangerous one, techniques for regulating your heart rate, and how to tell if a low or high heart rate is an emergency. Yoga , meditation , and breathing exercises also stimulate the parasympathetic nervous system and can lead to an overall lower heart rate.”