Which of the following activities has a MET value between 3.0 and 6.0?

Activities that fall within a MET (Metabolic Equivalent of Task) value range of 3.0 to 6.0 reflect moderate to vigorous intensity levels of physical exercise. A brisk walk, particularly at the pace of 3.5 to 4 mph, is a classic example of an activity that aligns with this MET range. At this speed, the individual is engaging in a physical effort that elevates heart rate and energy expenditure, thus within the defined MET interval.

In contrast, other activities like sprinting, cycling at high speed, and swimming laps typically exceed the MET value of 6.0 due to their high intensity. Sprinting requires maximum effort, leading to significantly higher energy expenditure than a brisk walk and, similarly, high-speed cycling and swimming laps generally demand a vigorous level of exertion, categorizing them as above the MET range specified in the question.

Thus, a brisk walk at the given speed is an ideal example of a moderate-intensity activity, which is why it correctly fits the criteria for having a MET value between 3.0 and 6.0.