This "walking" challenge will really test your limits. If you don't know where your traps are, this challenge will be the best anatomy lesson.
The Half-Mile Of Hell Challenge
How To Do It
Get a pair of 32kg kettlebells, plus one 28kg and one 24kg kettlebell. If you need to use dumbbells, use two 70 pounders, one 60 pounder, and one 50 pounder. Get to an area where you can walk 40 yards without turning.
Pick up the 32's and walk 40 yards down and back.
Pick up the 28 in one hand and walk down and back with the empty arm up, switching hands at 40 yards.
Then to complete the set, walk with the 24 in one hand overhead and the other arm up for 40 yards. Switch arms on the way back.
Rest where you need to and repeat for 4 total "sets."
That's 960 yards, well over half a mile. The goal is to complete the test in under 15 minutes. If you go over 15 minutes, stop there and record the total distance covered.
Notes: If you haven't been doing these walks or positions, start lighter and with much shorter distances and more/longer rests.