Zone 4 refers to a specific area in the context of exercise training, particularly in heart rate zones. It is characterized by a high intensity level, typically ranging from 80% to 90% of an individual's maximum heart rate. Training in this zone can improve cardiovascular fitness and endurance, making it popular among athletes and fitness enthusiasts. In addition to fitness, Zone 4 can also refer to geographical or zoning classifications in urban planning. These zones often dictate land use, such as residential, commercial, or industrial purposes, helping to organize and manage community development effectively.