What is resting heart rate?

Resting heart rate (RHR) is a measure of the average number of times your heart beats per minute (bpm) while you are in a state of rest (i.e., seated in a quiet place for at least five minutes). In other words, it is a way to quantify the work rate of your heart during rest. You may come across the term basal heart rate, which refers to the same thing, as it is considered a base or lowest value.

‍

Is there a difference between normal and healthy RHR?

According to American Heart Association (AHA) guidelines, a resting heart rate range between 60 and 100 bpm is considered “normal”. This might seem like a wide window, so other factors should be considered when interpreting this value. To minimize the window, we can simplify it to the concept that a lower resting heart rate is generally regarded as "healthy”. Importantly, the consideration of “healthy” will vary depending on the user’s age, sex, medical history, and behavioral or lifestyle factors, thereby making the value more intra-specific.

‍

More often than not, athletes or individuals who lead active lives have a lower RHR when compared to sedentary individuals. Furthermore, men tend to have a lower RHR when compared to women. This pattern is due to the size of a woman's heart being slightly smaller than their male counterparts; a smaller heart pumps less blood with each contraction and therefore needs to pump faster to achieve the same output. 

‍

Why is a lower RHR healthier?

A lower RHR is a sign of a strong and efficient heart muscle. A stronger muscle contraction results in a higher volume and rate of blood being pumped from the heart with each contraction; the heart needs to contract less often to achieve the same outcome. Simply put, a more efficient heart shows the ability to do more work with less strain.

‍

If you do not regularly engage in physical activity, a lower RHR may be reason enough to visit your physician, as it can be an indicator of a developing heart condition, heart arrhythmia, or disturbance in your heart rhythm. Furthermore, research has shown that higher RHR is associated with an increase in the risk of cardiovascular disease and all-cause mortality (Zhang et al., 2016; Jensen et al., 2013). 

‍

What affects a resting heart rate?

It is important to keep in mind that your RHR can be influenced by a range of factors and therefore fluctuates on a daily basis. Factors that have an immediate or long-term impact on RHR include the following: age, sex, fitness level, acute activity, body position, body mass index, the prevalence of a heart condition, higher cholesterol or diabetes, certain medications, smoking, caffeine, hydration, environmental conditions, sleep habits, emotions, and stress.

‍

Physical fitness correlates with heart muscle strength. The fitter you are, the better condition your heart is in, and the easier it is for your heart to do its job.

‍

‍

On a side note, while heart rate and blood pressure are related, having a low RHR does not necessarily mean you have normal blood pressure.

‍

How often should I check my resting heart rate?

Monitoring RHR might not be as exciting as monitoring other cardiovascular metrics such as heart rate variability, which has gained popularity over the last few years. However, knowing your RHR trend remains insightful in that it is an important indicator of overall heart health. Checking your RHR on a daily basis and comparing your most recent value to your baseline can give you an idea of how your body is coping with acute stressors.

‍

A consistently high RHR is an early sign that there may be something not quite right: your heart is either not working as effectively as it could or there might be an underlying heart condition. A variation between three and five bpm above or below your average or baseline may be a sign that your body is not coping with additional stress, and you may need to slow down for a few days to recover. 

‍

How to improve your RHR

Implement lifestyle changes to lower your RHR. These changes  include regular exercise and behavioral changes: 

• The ACSM recommends between 150 and 300 moderate to vigorous activity minutes per week, including both cardio and strength training sessions.
• Modify behaviors that increase your risk for cardiovascular disease, such assome text
  • Maintaining a healthy diet
  • Losing excess weight
  • Avoiding excessive alcohol
  • Avoiding smoking

‍

Citations:

Jensen, M. T., Suadicani, P., Hein, H. O. & Gyntelberg, F. (2013). Elevated resting heart rate, physical fitness and all-cause mortality: a 16-year follow-up in the Copenhagen Male Study. Heart, 99:882-887.

Zhang, D., Shen, X. & Qi, X. (2016). Resting heart rate and all-cause and cardiovascular mortality in the general population: a meta-analysis. Canadian Medical Association Journal, 188(3):E53-E63.

‍