Special Forces (capitalized) is the US Army Special Forces, aka The Green Berets. However, when you say “special forces” (lower case), it can mean any of the units mentioned above. Oh, and lets not leave out 160th SOAR!
For Special Forces, you’ll have to be Airborne Qualified or volunteer to go to Airborne School. Then, to be accepted to start training in the Special Forces Qualification Course, you have to pass Selection. Selection is a grueling, month long course. There is a minimum fitness level one must be at to stay. But it uses an overall scoring method. So if you score better in one event, you can score a little lower in the others. But this is just to get to stay. A person who scores the minimums is much less likely to pass all the little tasks, tests and trials.
To even start the Selection process, an applicant will need to score at least a 229 on the Army PT Test, without scoring less than a 60 in any one particular event.
There is a copy of the scoring sheet here: PDF!!!
Regardless of the applicants age, he will be graded in the 17-21 age category.
As you’ll see, the slowest a person is allowed to run is 2 miles in 15:54. But, of course, that’s just to stay. The person will still be required to perform and meet all the other standards during the course. I won’t go into details about what goes on there, but walking for 60km or so with a 60lb ruck sack is not just “something you read” 
Also, land navigation is a big important part of SF. So not only will you be walking around with all that weight over long distances, you’ll be alone in the forest with just a compass (no gps) and a map. Nothing ever gets cancelled for weather, either. So if there’s an ice storm and all the trees are exploding from the cold and limbs are falling on people and people are loseing toes from hypothermia and shit. . . you will still be required to perform. Well… you’re always allowed to quit if you want.
Once, or I should say “if”, you pass that successfully, you get to actually start your Special Forces training. There are 6 phases of training in all. The last of which is SERE school. Google “Special Forces Qualification Course” for lots of good information. Also Google “SERE” and “SERE C” for some info on that course. It’s no summer camp!!!
Oh… and don’t get a DUI while in the Q course. They’ll send you packing, and getting back in can be even harder than getting in the first time.
25 miles with a 60lbs ruck is nothing, really. It can be done repeatedly for several days with no blisters.
60 days of only 2 hours of sleep daily. . . that’s only a slight exageration of Ranger School. There will be pleanty of nights where you get 4 hours or so of sleep. But keep in mind how physically demanding the days are and how little food the soldiers get.
But ask anyone whose done these schools in the past, they’ll tell you
“The Schools are Getting Easier!!” :rolleyes:
Everyone always seems to have gone through “Back whhen it was hard” 