A little back story on my running experience.
I was always pretty active as a kid, and like school work, athleticism came pretty natural for me without much effort. However, I never ran track. I thought running in circles was a silly idea, so I did a little theatre, badminton, and volleyball. All were team activities or sports where you measured against an opponent. I only started properly running around a track when I decided that I was going to join the Marine corps. Even then, it was just an exercise of seeing if I could even physically run an entire 3 miles.
Fast forward past the messy emotional details, I ended up in the Army. This should have been a plus because the Army only requires a 2 mile run. However, that 2 mile run in the Physical Training(PT) test kicked my butt everytime. I passed, but sometimes barely, and it always hurt. Yes, during regular PT my unit ran a few miles each week. But I always dreaded every step and the emotional struggle and frustration never let up. Even running on my own was painful, stress inducing, and apparently not very effective because I never quite aced the run part of the test.