The problem: One of the most common injury-causing running form mistakes is overstriding, or landing heel first with your foot well ahead of your body's center of gravity. Some runners assume that a longer stride will improve their speed or running efficiency, but that's not the case. Overstriding wastes energy since it means you're braking with each foot strike. It could also lead to injuries such as shin splints.
The solution: Make sure that you don't lunge forward with your feet. This is especially important when running downhill. Focus on landing mid-sole, with your foot directly underneath your body with every step. A short, low arm swing is the key to keeping your stride short and close to the ground. Try to keep your steps light and quick, as if you're stepping on hot coals.
吐槽点：小步贴地前进，又轻又快，真像小老太太碎步，太不性感了呵。