Those participating in Primal Quest, a physically intense “expedition adventure race,” are getting ready for their grueling, eco-conscious adventure this summer. Known as the “ultimate test of human endurance,” the 10-day competition (June 25th through July 4th) will see more than 100 co-ed, four-person teams climb, swim, kayak, raft, and mountain bike across 400 miles of rugged terrain.

Started in 2002 with the twin goals of “bringing a world-class, multi-sport expedition race to North America” and “responsible use of back country lands to promote a positive environmental message,” the event is usually held out West––in Colorado, Washington, and California. This year’s location has yet to be announced, but wherever it is, its environment will be treated gently. All participants must be “Leave No Trace” certified, meaning, essentially: “Teams only travel where permitted; do not build campfires; and strictly adhere to pack it in, pack it out rules.”

Though only 50% of the teams even complete the insane journey––which includes class III and IV rapids, and “ascending and descending 30,000 cumulative feet of rope”––the winning group gets $250,000. Teams are varied in their names (e.g., Jen’s men, Caffeine, Eco Squawllywood, Dancing Pandas) and intention: Some teams like LeukemiaCure.com are raising money for cancer research. It’s likely that most of the corporate teams (Subaru, Nike, Oakley) also plan to donate proceeds to charity. Primal Quest itself makes donations to outdoor and environmental education for youth. If you want to root for particular teams, you can track their progress through team blogs here.

Adventure racing was not born on reality TV. Not counting the actual Odyssey, this kind of event started in New Zealand in the 1980’s, and a decade later events like Raid Gauloises and the Eco-Challenge TV show popularized it, according to the Primal Quest site. As in past years, Primal Quest will be thoroughly filmed, with parts being shown on network television.

The good (or really bad) news for you and your fitness regimen is that racer registration is still open.