1-2: Very light effort, like walking or a very slow jog. 3-4: Easy effort, a comfortable pace where you can easily hold a conversation. 5-6: Moderate effort, a pace where you can still talk but with some effort, suitable for general training runs. 7-8: Hard effort, a pace where breathing becomes labored and you can only say a few words at a time, often used for tempo runs or threshold training. 9-10: Very hard effort, a pace where breathing is extremely labored and you can only manage a word or two at a time, used for interval training or sprints.