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Active Heart Rate: How to Measure It, Normal Values and Trends

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What is it?

Active heart rate is the rate at which the heart beats during activity or exercise. Heart rate is a highly responsive physiological measure. It is important to note that heart rate is a response variable to many factors. Therefore, the purpose of measuring heart rate is to measure the body’s physiological reaction to the work being performed.

How is it measured?

There are many ways to measure heart rate during physical activity, but some are more reliable than others. The typical ‘gold standard’ method is through electrocardiography, whether 12-lead or single-lead.

Additionally, photoplethysmography, or PPG, can be used to measure pulse waves to obtain heart rate. Due to the nature of different wavelengths utilized during PPG measurements, green light LED has been shown to be best at detecting pulse waveforms during exercise. Red and infrared light are motion intolerant and are not recommended for active heart rate monitoring.

The Biostrap ecosystem contains both a chest-worn ECG-based heart rate monitor as well as a green light PPG sensor worn on the arm. The Biostrap activity HRMs are recommended for use during activity to obtain proper active heart rate. The Biostrap EVO device, equipped with red and infrared PPG does not record during exercise due to motion artifacts; therefore, it’s best utilized for monitoring sleep and recovery metrics captured overnight.

Correlation with health

The use of heart rate during activity and exercise is not recommended for or capable of diagnosing medical conditions. However, heart rate during activity and exercise can provide a lot of information about heart health and performance.

Typically, when examining individuals during exercise, a lower heart rate at an equivalent workload suggests increased cardiovascular health.

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Normal Values

In theory, any value existing between resting heart rate and maximum heart rate, or MHR, are ‘typical’ values for exercising. MHR is considered the upper limit of what your cardiovascular system can handle during physical activity.

To roughly calculate your individual MHR, perform the following equation: 220 minus your age.

Interpreting Trends

In general, performing the same task, an individuals’ heart rate should be lower after cardiovascular fitness adaptations.

However, many variables can influence heart rate during exercise that may alter this trend. Heat, emotional stress, caffeine consumption, movement economy, and dehydration are just some of the factors that can influence day-to-day variation in exercise heart rate at the same workload. Cardiovascular adaptations may decrease the reactivity of heart rate to some of these influences, so a trend toward a lower heart rate should still be observed over time.

Note, this should not be confused with active heart rate during a single exercise bout. Heart rate should remain proportional to intensity, and thus depends on the workload applied to the activity.

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