The 99th percentile for a two-mile run was 11:50 for 17–21 year old males. I managed to beat that exactly once in life and then never again. These days I purpo

The 99th percentile for a two-mile run was 11:50 for 17–21 year old males. I managed to beat that exactly once in life and then never again. These days I purposefully slow down when running if I find my heart beating too quickly. I wear a Garmin heart rate monitor. Even if I feel like I could push myself to a heart rate of 200+ per minute, it's best not to.