Runners can effectively increase their overall speed not by increasing the length of each running stride, but by trying to increase the actual speed of each individual stride. In the ideal stride, your foot should always land on the ground directly beneath your body instead of landing in front of you.
Running is a wonderful and effective way to get in shape, but it can also lead to extreme muscle fatigue and exhaustion. For one week out of every two months, cut the average length and intensity of your regular runs in half. This period of rest allows your body to more effectively repair itself and avoid chronic running injuries.