Here, when not taking online courses on subjects like cryptology, identity manipulation and bomb defusing, students pay to be threatened with Taser guns, thrown into mud pits and subjected to deafening rounds of live ammo fired over their heads.

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These are usually one day affairs and are typically based on a running race of 3-12 miles, but those miles are fraught with hazards not found on any normal marathon or half-marathon course, from mud pits to vertical walls, fiery flame barriers to electric shocks, ice plunges to crawls under barbwire.

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