Anaerobic Zone. The anaerobic zone is slightly more intense than the aerobic zone. Anaerobic means without oxygen, so don't be surprised if you are unable to speak except for short words at a time in this zone. The anaerobic zone is 80 to 90 percent of your maximum heart rate.erobic Zone. The aerobic target zone is 70 to 80 percent of your maximal heart rate. Multiply your maximum heart rate by this percentage to determine the intensity you must maintain to remain in this zone.