The more I study on this subject, the more confused I become. I used to think that only lean, rangy people could really walk, but I’ve hunted with some lardasses who could boogie up the mountains with anyone.

That notwithstanding, the three people I would least like to make a forced march with are all over six feet and lean. (Being tall gives you an advantage as you take fewer steps to go a given distance, and of course it helps not to haul extra weight around.) The three of them also work at it fanatically.

Brian Maness is one of the three. He’s an outdoor photographer who has to lug a video camera and a 6-foot tripod at high speeds through all sorts of rough country. On a bet, Brian walked from a dead elk back to our truck in an hour flat. It was 5 miles, almost all of it up a long ridge, and no one, including the guides, thought he could even finish, much less do it in 60 minutes. It would have taken me 3 days and a dozen bottles of oxygen. The Army says that 3 mph is the recommended pace for a route march, and that 4 is about the best that can be done by troops carrying a combat load. Five mph, uphill, at 8,000 feet, carrying a video camera, is beyond me.

Being able to do stuff like this, I’ve come to believe, is as much mental as physical. I’ve talked with half a dozen SEALS about the subject, and to a man they say it’s simply determination. Everyone who reports to BUDS is in shape, but at the end, the ten or a dozen sailors who go on to the next stage are the ones who have decided to make it or die in the effort.

One very, very large SEAL said: “BUDS isn’t hard. You just get up in the morning and do what they tell you to.” I’ve never heard that before, but then this guy is more of a walrus or a sea lion than a SEAL.