6 mi. Dr Larivee says try a run in the neighborhood to see how your leg feels. I did a 6 mi run at regular pace, 8-8:30 and my right calf fails after 2 miles. I figure instead of going home, I’ll see what happens after it spikes pain. It doesn’t get worse in the next four miles, it gets numb. I think I can run with this, I hope it can last all 26 miles.