On Sunday, I had the opportunity to be the object of my own little case study. The topic? How fast can I complete the 13.1 mile run portion of a Half Ironman (Boulder 70.3) after not having run for 4 months due to a broken fibula and wearing an air cast on my leg. Going into the event, I planned to step off the course if the leg started feeling worse, and also wore the air cast during the 56 mi bike portion to provide the greatest possible stability going into the run itself. The outcome was interesting – and somewhat encouraging. I started off conservatively, going through the first 6 miles at about 7:05 pace/mile. At that point, the heat and lack of run training reared it’s head, and I slowed considerably from miles 7-10. However, for a variety of reasons, my head got back in the game the last few miles, holding a 6:15-6:30 pace to finish up for a final time of 1:39 on the run (7:35/mile). This was about 13 minutes slower than I’ve run on that course, but it was very interesting to see that a complete lack of run training along with the air cast only resulted in a 1 min/mile difference. Application? Next season I’ll put more emphasis in training on the bike and swim, knowing the run result will be there, even with less total mileage than in the past. Interesting…