heartrate

Heart rate, or pulse rate, is the number of heartbeats per minute (bpm). It reflects how hard the heart is working and how the autonomic nervous system regulates cardiac activity. At rest, adults typically have a resting heart rate of about 60 to 100 bpm, though well-trained athletes may have lower resting rates. Heart rate increases with physical activity and tends to fall during recovery. Pediatric normal ranges vary with age.

Measurement can be done by palpating a peripheral pulse (such as at the wrist or neck) or with electronic devices that monitor heart activity. Wearable devices, chest straps, and electrocardiogram (ECG) monitors provide continuous or periodic heart-rate data. Some devices estimate heart rate using optical sensors (photoplethysmography).

Factors influencing heart rate include age, fitness level, and autonomic balance. Sympathetic activation raises rate, while parasympathetic activity lowers it. Other influences include medications (for example, beta blockers slow the rate), caffeine, nicotine, temperature, hydration, altitude, illness, and emotional state.

Maximum and target rates are used for exercise planning. A common estimate for maximum heart rate is 220 minus age, though individual values vary. Target zones for training are often set as percentages of this maximum. Heart-rate recovery after exercise and heart-rate variability are additional measures sometimes used to assess cardiovascular fitness and autonomic function.

Clinical relevance: a persistently high resting heart rate (tachycardia) or low resting rate (bradycardia) without explanation can signal health issues such as arrhythmias, thyroid or electrolyte disorders, or heart disease. Changes in heart rate may prompt medical evaluation, particularly if accompanied by other symptoms.