Which of the following best describes aerobic exercise?

Aerobic exercise is best characterized by continuous and rhythmic activities that increase the heart rate and improve the body’s efficiency in using oxygen. This form of exercise primarily involves large muscle groups and can be performed for extended periods. Examples include running, cycling, swimming, and dancing, all of which require sustained effort.

The key aspect of aerobic exercise is its ability to enhance cardiovascular endurance, promoting better heart and lung function. It helps improve overall fitness levels and can be performed at varying intensities, but the fundamental nature remains that it involves ongoing, rhythmic movement rather than short bursts or strength-based routines.

Contrasting with the other options, which include activities like strength training, which focuses on muscle building and may involve short, intense efforts, or static stretching routines aimed at improving flexibility, aerobic exercise's continuous nature distinctly contributes to an individual's aerobic capacity.