What is the most accurate method for measuring someone's heart rate?

Measuring heart rate can be performed using various durations, but the most accurate method among the given options is to measure it over a full 60 seconds. This allows for capturing a complete cycle of heartbeats, which mitigates the chances of anomalies or fluctuations that can occur over shorter intervals.

When measuring heart rate over a shorter period, such as 15 seconds or 30 seconds, you may not obtain a representative average, especially if the heart rate has just recently changed due to activity level or other factors. A one-minute measurement encompasses enough beats to smooth out any irregularities and provide a more reliable reading.

Additionally, measuring over two minutes is not necessary for most practical purposes and can be impractical in many situations. Therefore, while longer measurements may provide even more data, 60 seconds strikes a balance by offering accuracy and practicality for assessing heart rate in most scenarios.