Long story short:
its an event.
backpack full of bricks.
runing.
crawling.
pushups.
bear crawls
12+ hours
carried logs, tree's, railroad ties, etc. (we carried 4 rail road ties 7.75 miles the most recent one)
buddy carries.
its basically an event where 20 people come together in a city in the middle of the night with goruck bags filled with bricks and headlamps and try and push yourselves to and past the absolute limit of physical demand. you burn around 15,000 calories during the challenge.