If you re training hard and eating right but still not getting the results you want from your running, the problem could be in your form. Poor form means wasted energy, which means slower times. The good news is that you can improve your form by improving weaknesses within your body. If you want to run your best, a strong midsection is essential.
Distance runners require maximum economy of energy expenditure for best results.
This means having a good technique as well as enough muscular strength to run with correct posture. With proper posture, you use only those muscles that are required to move your limbs and thus propel yourself forward. When this occurs, you won t have exaggerated movement of the arms, shoulders, or hips - all of which use large amounts of energy. To minimize extraneous movements, hold a stable and constant position from the waist up while running. This means that your trunk should be erect, with your shoulders directly over your hips.