Im a high school sophomore and i race the 3200 meter. Ive noticed in my races that as the race progresses farther and farther my stride rate gradually goes from 175 to 190 and my stride length goes from 5.3 to 4.9 feet per stride. Why is this how can i prevent it or is it even bad. Ive also noticed a lot of calf soreness afterward which may be a factor.