Which of the following is an expected benefit of aerobic exercise?

Engaging in aerobic exercise is well documented to bring about various physiological improvements, one of which is a reduction in resting heart rate. This occurs because regular aerobic activity enhances cardiovascular efficiency; the heart becomes stronger and more effective at pumping blood. As a result, it doesn’t need to beat as frequently when at rest to maintain adequate blood flow, leading to a lower resting heart rate.

This adaptation is indicative of improved cardiovascular health and endurance capacity, demonstrating the body's ability to utilize oxygen more efficiently during both exercise and at rest. On the other hand, options that suggest a decrease in lung capacity, an increase in body fat percentage, or decreased overall endurance do not align with the established benefits of regular aerobic exercise; these factors generally suggest negative health outcomes which are contrary to the goals of aerobic training.