Which type of activity is described as anaerobic?

Anaerobic activity refers to exercises that are performed at high intensity for short durations, where the body relies on energy sources that do not require oxygen. Weight lifting fits this definition as it involves short bursts of high-intensity effort, such as lifting heavy weights. During these activities, the body primarily uses glycogen stored in muscles for energy, rather than relying on oxygen intake.

In contrast, activities like cycling, marathon running, and swimming can vary in intensity but are generally classified as aerobic exercises, especially when performed over longer durations. These activities involve sustained effort and primarily use aerobic pathways for energy, relying significantly on oxygen. Thus, weight lifting stands out as the correct example of anaerobic activity due to its reliance on energy systems that do not depend on continuous oxygen supply during the exertion.