When your mom told you stand up straight, you probably had no idea that she was also helping your running technique. Running efficiently and pain free has a lot to do with your posture. Keep your head in line with your spine, your shoulders relaxed, and your torso over your hips. A simple way to stack all these body parts one on top of the other is to gaze naturally at the horizon as you move forward. Adjust your eyes and chin so they are parallel with your body. It's tempting to look down at the ground or gaze at the peak of an upcoming hill, but this can overstretch your neck and cause your shoulders to hunch up toward your ears. Not only will gazing at the horizon prevent pain during and after your run, but it'll also make your workout easier.