The Colfax Half Marathon and the Rocky Mountain Half Marathon were held three weeks apart. I wanted to take a look to see how many individuals ran both races and how their times compared.

First, let’s talk about the differences in the course. The Colfax Half Marathon is super flat, with few hills, while the Rocky Mountain Half Marathon has a punishing uphill going from downtown up to Sloan’s Lake. However, the Colfax Marathon was run on a warmer day, while the Rocky Mountain Half Marathon was run with a slight rain and cool temperatures. There also is the issue of fatigue, in having run two half marathons in a three week time period.

There were a total of 99 runners that ran both races. That surprised me that means approximately 10% of the runners who ran the Rocky Mountain Half Marathon had competed in the Colfax Half Marathon three weeks earlier. If you’re in the marketing business, those are good numbers to know. Of those 99 runners, 48 (48%) of them ran faster at the Rocky Mountain Half Marathon, the remaining 51 (51%) had a faster time at the Colfax Half Marathon.

The runners who ran faster at the Rocky Mountain Half Marathon had an average improvement of 6:59, and a median improvement time of 3:45. The runners who ran faster at the Colfax Half Marathon ran on average 4:22 minutes faster, and a median improvement time of 2:59.

The data surprised me. I thought the Rocky Mountain Half Marathon would post slower times, due to the tougher course and the runners having run two half marathons in a period of three weeks. Personally, I’ve never done two half marathons that close together and I’m not sure if I even would attempt it. Your fitness level isn’t going to improve in three weeks. The only variable is the heat and the Colfax Half Marathon started at 6am and it was relatively cool at that time and most of those runners are going to finish between 8am.

Thoughts?