What defines 'vigorous intensity' in exercise?

Vigorous intensity in exercise is characterized by activities that significantly elevate the heart rate and breathing rate, indicating a high level of exertion. When engaging in vigorous intensity activities, individuals typically find it challenging to hold a conversation due to the increased demand for oxygen and energy. This is manifested in activities that cause heavy breathing and clearly more effort compared to those that might feel easy or moderate.

For instance, running, high-intensity interval training, or fast-paced cycling would fall under this category, as they increase cardiovascular effort and caloric burn effectively. The other activity choices listed do not match this definition; light walking would represent lower intensity, moderate cycling falls into a middle category, and yoga or stretching focuses more on flexibility and controlled breathing rather than heart rate elevation. Thus, the correct identification of vigorous activity as those that cause heavy breathing and increased heart rate highlights the importance of understanding exercise intensity for effective training and fitness assessment.