The best type of physical activity for building endurance is aerobic exercise. Activities such as running, cycling, or swimming primarily enhance cardiovascular capacity and stamina over extended periods. These exercises train the body to utilize oxygen more efficiently, enabling longer durations of physical exertion. For optimal endurance training, incorporating moderate-to-high intensity workouts and consistent practice is essential. Endurance activities also improve muscle efficiency and overall physical fitness. It's important to gradually increase intensity and duration while allowing for adequate recovery to prevent injuries and promote adaptation.