Concentration and focus is like a skill and can be exercised to be improved.
While running, I like to perform a particular concentration drill that I’ve developed. Every step is a count of 1 until 1 reach 16, then I start over. But that’s not all. I maintain a rhythm of breathing out every 4 counts, that is, on 4, 8, 12, and 16. If I’m really winded, I’ll breathe out every two counts: 2, 4, 6, etc.
But that’s not all. I found that my mind could still wander while running, counting and breathing. So I developed a task which can occupy my conscious thought completely. I visualize a set of 4×4 squares for each count, as shown below.
I find that this exercise helps keep me calm and reduces my propensity towards distraction.