Which of the following methods of monitoring intensity is most appropriate for a client in her second trimester of pregnancy?

In the context of monitoring exercise intensity for a client in her second trimester of pregnancy, the use of Rate of Perceived Exertion (RPE) is particularly appropriate. This method involves the client's subjective assessment of how hard she feels she is working during exercise, which allows for a personalized and intuitive gauge of exertion.

During pregnancy, physiological changes such as increased blood volume, hormonal shifts, and changes in lung capacity can affect heart rate responses to exercise. As a result, heart rate alone may not provide an accurate reflection of effort. Moreover, certain guidelines suggest that pregnant individuals should aim for a moderate level of exercise intensity, which can vary from person to person. Using RPE allows the client to regulate her intensity based on her unique perception of effort rather than solely relying on external metrics that may not account for her current physiological state.

Additionally, methods like metabolic equivalents (METs) and caloric expenditure can be less practical for real-time monitoring and may not account for the individual's subjective experience during exercise. Thus, the RPE scale stands out as a reliable and safe tool for pregnant clients, encouraging them to listen to their bodies while making exercise choices.