The ColderBOLDER 5K  will be held on December 6th at the CU campus. Dubbed the “polar opposite” of its sister race, the BOLDERBoulder, the event started in 2003 and has grown in popularity. With a quick course and festive holiday atmosphere, this race sells out every year. Keep reading to discover what you need to know.

How to Participate 

The ColderBOLDER isn’t open to everyone who wants to start their holiday season on a healthy note or break into a sweat from cold. Instead, registration is by invitation only and limited to those who participated in the 2025 BOLDERBoulder. If you took part in the summer race, you should receive an invitation for December’s event via email. 

The Waves

Runners participating in the ColderBOLDER are encouraged to run with others at a similar pace. The event is split into 13 invitational waves, with wave assignments based on each runner’s finishing time during the most recent BoulderBOLDER.  

There’s also an open race for runners of all speeds, along with a walking wave. The walking wave isn’t a race but an opportunity for those who want to enjoy a fun walk around CU’s campus. A limited number of virtual registrations are available for people who can’t attend in person but want to join the celebration remotely. 

The Awards

The ColderBOLDER awards a finisher’s medal to all participants, along with a special cold medal for the top six finishers in each race. Participants will also enjoy burritos, doughnuts, coffee, hot cocoa, and other refreshments after crossing the finish line. 

The ColderBOLDER is a great way to take time for yourself during the hectic holiday season. If you ran the BOLDERBoulder, check your email for more information on how to run through this winter wonderland.