Which metabolism is linked to longer-duration activities and typically requires oxygen?

Aerobic metabolism is the correct choice because it is the metabolic process that requires oxygen to generate energy for longer-duration activities. In this type of metabolism, carbohydrates and fats are broken down in the presence of oxygen to produce energy, carbon dioxide, and water. This process is efficient for sustained activities, such as long-distance riding or any endurance exercise, as it can produce a significant amount of ATP (adenosine triphosphate), which is the energy currency of the cell, over an extended time.

In contrast, anaerobic metabolism, including anaerobic alactic metabolism and fermentation, primarily occurs in the absence of oxygen. Anaerobic pathways are typically associated with shorter bursts of high-intensity activity where the body cannot supply oxygen fast enough to meet energy demands. These processes allow for quicker energy production but are not sustainable over long periods as they lead to the accumulation of lactic acid and result in fatigue.

Therefore, aerobic metabolism is specifically linked to activities that are longer in duration and rely heavily on oxygen, making it the appropriate choice for this question.