Running is all about putting one foot in front of the other. Sounds easy enough, right? But if your running form is off, then you'll likely end up with aches, strains, and injuries that could keep you from lacing up your sneakers at all. Make sure to avoid these running-form mistakes the next time you hit the treadmill, trail, or road, especially if you're training for your first half  or full marathon .
Prevent neck strain and encourage an open throat for easy breathing by keeping your head stacked over your spine. Avoid tilting it up or down toward your chest, as this could strain the neck. Correct head position also encourages a straight, upright stance, which makes you a more efficient runner. Be mindful about relaxing the muscles in the face, wearing sunglasses to prevent squinting, and relaxing your jaw, since not doing all three of these can lead to a headache.
Without even realizing it, you may be running with your upper back and shoulders tensed up toward your ears. Every so often, take a nice deep breath in and as you exhale, relax your upper torso and actively roll your shoulders back and down toward your pelvis. Do a self-check to make sure your shoulders are stacked over the hips — hunching the upper body forward not only makes it difficult to breathe, it also puts pressure on your lower back and knees.
Leave the side-to-side swaying arms for the dance floor. Your arms shouldn't move across the midline of your body when you run — it uses up energy, tires your muscles, and actually interferes with the forward motion of your body. To increase your speed and endurance, focus on pumping your arms in a fluid motion, forward and back, keeping your elbows at 90-degree angles.
Clenched fists translate to tense arms and shoulders, which tires your muscles and can cause a dull, achy sensation. Not to mention, it also makes you look like an angry runner! Maintain a sense of relaxation in your torso by running with a slightly open fist, pretending you're holding an egg in each palm. With a normal running pace, the hands shouldn't come higher than the lower breastbone.
Hips and belly
Many runners complain of lower back pain, and one reason is because they don't engage their abs. While running, concentrate on drawing your navel in toward your spine to keep your pelvis and lower spine stable. With the hips staying directly below the shoulders, tuck your pelvis under slightly as if you're sitting on a stool. This will help you engage your lower abs and keep the spine straight.
Where your feet strike is a big debate among runners. In order to land with the least amount of jarring pressure on your ankles and knees and have the ability to push off the ground with great force, it's best to land on the midfoot — not on the heel. The foot should be in line with the knee and chest when it makes contact with the ground. Then roll forward quickly onto the toes, pushing off the ground with each step. Landing softly is key — no one should hear you pounding your feet as you run. Think of yourself as a deer, quietly and effortlessly bounding as you move.