Normal Heart Rate in Adults
A normal resting heart rate for adults is between 60 and 100 beats per minute. 1
Normal Heart Rate Ranges by Age
Heart rate varies significantly across the lifespan and is influenced by several factors:
Adults (age 20+): 60-100 beats per minute
- Adult females: average 74 beats/min
- Adult males: average 71 beats/min 1
Children and adolescents:
- Under 1 year: average 129 beats/min
- Age 5: average 96 beats/min
- Early adolescence: average 78 beats/min 1
Factors Affecting Normal Heart Rate
Several factors can influence what is considered "normal" for an individual:
- Age: Heart rate is inversely associated with age, decreasing from infancy through adolescence before plateauing in adulthood 1
- Sex: Women typically have slightly higher resting heart rates than men (74 vs. 71 beats/min) 1, 2
- Physical fitness: Well-trained athletes may have resting heart rates as low as 40-60 beats/min 3
- Time of year: Seasonal variations exist, with lower heart rates typically observed in summer (minimum in July) and higher rates in winter (maximum in January) 2
- Sleep duration: Longer average sleep duration is associated with lower resting heart rate 2
- Body mass index (BMI): Higher BMI is associated with higher resting heart rate 2
Clinical Significance
Bradycardia
- Defined as heart rate <60 beats per minute
- May be normal in well-conditioned athletes
- Clinically significant bradycardia is generally <50 beats per minute when symptomatic 4
- Prevalence of clinical bradycardia (HR <60 beats/min):
- 15.2% in adult males
- 6.9% in adult females 1
Tachycardia
- Defined as heart rate >100 beats per minute
- Prevalence of clinical tachycardia (HR ≥100 beats/min):
- 1.3% in adult males
- 1.9% in adult females 1
- Heart rates ≥150 beats per minute are more likely to cause symptoms of instability, particularly in patients with impaired ventricular function 5
Individual Variability
Research shows significant inter-individual variability in normal heart rate:
- Individual "normal" heart rates can differ from another person's normal by as much as 70 beats per minute 2
- Within individuals, resting heart rate remains relatively stable over time with small seasonal variations 2
- About 20% of individuals experience at least one week per year where their heart rate fluctuates by 10 beats per minute or more 2
Clinical Implications
- Elevated resting heart rate is an independent risk factor for cardiovascular disease and mortality in healthy adults 3
- Each 10 beats per minute increase in resting heart rate can substantially increase the risk of adverse cardiovascular outcomes 6
- When evaluating heart rate in clinical settings, consider the individual's baseline, age, sex, and other factors rather than applying a strict cutoff
Understanding normal heart rate ranges helps clinicians identify potentially concerning deviations that may require further evaluation or treatment.