Start with the 400m run, aiming for a strong pace to get your heart rate up. Transition into the pull-ups, focusing on controlled movements—use a full range of motion to engage your back and arms effectively. Move smoothly into push-ups, ensuring proper form by lowering your chest to the ground and keeping your body straight. Finally, tackle the air squats with depth and form, keeping your weight in your heels and chest up. Finish strong with another 400m run to close out the circuit, maintaining your pace to the finish.