I ran track in high school. My event was the 800 meters (1/2 mile). This is a fast race and my running form has never really changed much. I tend to swing my arms quite vigorously and have a long stride. While this is great for speed events, it expends a lot of energy. I would not be able to maintain this running style for more than an hour. I have been focusing on keeping my posture straight, my hips forward, my arms close to my body, and have shortened my stride quite a bit. This has lessened the bounce a bit and helps me turn my legs over faster. It felt a bit awkward at first but now is beginning to feel natural. I make sure to pay attention to the runners around me. I note their form and compare it to my own.