Underwear Run
Take it off. It's for a good cause.
Underwear Run
It's just like spandex, right?
Underwear Run
Undies mandatory. Costumes optional.

There’s no better way to cope with pre-race stress than stripping down to your skivvies. In public. At the lakefront. On a Friday. Join us for a unique kickoff to an incredible weekend:

Underwear Run

2018 details will be posted at a later date.


The Underwear Run is a fixture to our sister race, the 2XU New York City Triathlon, and a new addition to the 2017 Transamerica Chicago Triathlon weekend. This 1-mile fun run will be hosted at the lakefront on the Friday of race weekend. No transitions, no timing chips, no expensive race gear – just 500 strangers having a good time running around in their underwear. Registration is limited to the first 500 registrants.  Gear check will be provided on site for extra clothing.  All participants will receive swag, complimentary photos, refreshments and more.   Perhaps it’s time to start that core routine?


Strip for A Cause

Do you have old clothes that never see the outside of your dresser? Bring them along and do your part for the less fortunate! Our friends at Brown Elephant are excited to partner with this year’s inagural Undie Run and will be collecting donations on site!


Best UN-dressed Costume Contest

What could be more fun than running at the lakefront in underwear? Running at the lakefront in an underwear costume! We will be hosting an undie UN-dressed costume contest before the race. Gather up your friends or go it alone and strip down to create a prize-winning costume and win a gift card from our title sponsor.  As this fun event benefits the 100 Club of Chicago, extra points will be given to costumes with a first responder theme!

Individual Costume                                                     Group Costume

1st place: $200                                                             1st place: $300

2nd place: $100                                                            2nd place: $150

3rd place: $50                                                              3rd place: $100


100 Club of Chicago

A $10 donation is suggested but not required to register, with 100% of proceeds going to benefit the incredible work of the 100 Club of Chicago. The 100 Club supports the families of brave first responders in the public safety, police and fire departments throughout Cook and Lake Counties, who lost their lives keeping the public safe. In honor of this cause, don’t forget to dress (or undress) in your best first responder undies.


It’s about to get drafty in here!