Keith Burgess-Jackson, J.D., Ph.D.

I just did my 900th five-kilometer run. (That's 3.107 miles.) This is by far the most common distance for me, in part because I've done a lot of 5K races. I've done 278 runs of 6.6 miles, 267 runs of 2.0 miles, and 239 runs of 4.3 miles. I've done 11 marathons. All told, I've run 2,036 times, for a total of 8,968.24 miles. My average run is 4.4 miles. It's hot here in North Texas, but I love it. It was 92.8º when I finished my run. What are you doing for exercise?