There’s a reason why the Rangers, the Green Berets, and many other Special Operations Units use unknown distance ruck marches to assess candidates. The ruck is often called “the ultimate equalizer”. It can make a 250lbs linebacker fall by the wayside while a 140lbs teenager drives on. The ruck does not discriminate and it does not relent. 

But those who really know, know that the unknown distance march isn’t about the weight of the ruck or the number of miles covered.

It’s about the uncertainty – the ability to persevere through continuous hardship for however long it takes. It’s about learning to focus on the mission, not the moment.