What is a basic guideline for determining an individual's resting heart rate?

Measuring the pulse after waking up, before getting out of bed, is considered a fundamental guideline for determining an individual’s resting heart rate because it reflects the heart rate in its most relaxed state. At this time, the individual has not engaged in any physical activity that could elevate the heart rate or have consumed food. This approach minimizes variables that could influence heart rate, providing a more accurate and consistent reading.

In contrast, measuring the pulse while standing up may not yield an accurate resting heart rate, as being upright can naturally elevate heart rate. Measuring the heart rate during exercise is not applicable for establishing resting heart rate, as physical activity dramatically increases heart rate. Similarly, taking the pulse after eating can also lead to an increased heart rate due to the body working to digest food, which again leads away from an accurate measure of resting heart rate.