MMA fighting: Inside look at the brutal sport's rising popularity and danger

Mixed martial arts, or simply MMA, is cage fighting that mixes punching, kicking and grappling. Likened to human cockfighting and blood sport by detractors, its intoxicating mix of athleticism, intensity and violence delivers something people have been lining up to see since Rome built the Colosseum.

Still in its infancy, MMA already has entrenched itself in popular culture. It is a success on pay-per-view and cable, and it has started to gain a foothold on network TV.

But hidden from the excitement of fight night is a jarring world few outsiders see. The training, preparation and sparring required before even stepping into the chain-link-enclosed cage is unlike anything in sports, including boxing, the New Jersey Star-Ledger reports.