Didn't they have coverage of this on ESPN or something last year?  I remember watching it on TV at some point

You've just finished a full day of parachute jumps, distance runs and other tests designed to breach the highest levels of physical endurance.

Previously unknown muscles are introducing themselves rudely and begging you to sit down. But you can't because you're six miles into a 20-mile road march.

When -- or if -- you reach the finish line, you get a one-hour break before it's time for more marching.

Welcome to the David E. Grange Jr. Best Ranger Competition.

Thirty-eight United States Army Rangers will take part today through Sunday in the 21st annual competition at Fort Benning, with events scheduled around the clock for 60 hours. The competition is designed to test not only the Rangers' physical endurance, but also their tactical thinking ability, their skills as a soldier and their ability to work together in two-man teams.

"The physical fitness and cardiovascular events are certainly a big part of it," Maj. Michael McNally said. "But they're only one part. Physical fitness isn't going to help you hit the targets when you're shooting. It isn't going to help you transmit a message from a radio. This competition measures a wide range of abilities."

The competition begins today at 6 a.m. with a physical training event at Malvesti Field. From there, the schedule is relentless. There's a distance run at 7:30 and a pair of M4 rifle competitions from 9 a.m. to 12:30 p.m. Then there's a spot jump, a litter carry and a canoeing event.

And that's all before nightfall the first day.

If history is an indicator, by the time the awards ceremony is held Monday, all of the competitors will be exhausted -- and some are likely to be absent. The 2002 competition began with 44 teams; only 17 finished.

No event eliminates more competitors each year than the road march -- a grueling four-hour, 20-mile trek with a 60-pound pack.

"At the last competition, we lost 50 percent of our teams during the road march," McNally said. "It's an extreme physical event. It's an elimination event."

McNally hopes more teams survive the road march this year as the overall field is already small because of heavy troop deployment around the world. The 19-team field is less than half the normal size for the Best Ranger competition.

Still, Fort Benning officials are pleased to be holding the competition again after a one-year hiatus. The event was canceled for only the second time in more than two decades last year because of Operation Iraqi Freedom and Operation Enduring Freedom. The competition was also canceled in 1991 because of Operation Desert Storm/Shield.

"We have mixed feelings because a lot of the soldiers who might normally take part in the competition are deployed," McNally said. "But we felt like we needed to hold the competition because it gives the Army a chance to showcase what its soldiers can do."

It also allows the Rangers to learn something about themselves.

"We always ask them, 'Why do you do this? Why do you climb this mountain?' " McNally said. "And just about every competitor will tell you they love the challenge."