Edit - I just realized... Why the hell did you put this in "About Ranger School"? This is more of a general question rather than one based directly on the fun of going to Ranger School.
Anything is a good start. Just remember, unless you've worked out consistently in some form before a consideration of joining the military, you need to start off somewhat slow like it has for everything there. That doesn't sound to me as if it would push anyone in half decent shape, but who knows.
I suggest some form of sprinting with the running as well, not just flat out distance running. You need to build strength with the endurance. Also, do burn outs with the sit-ups and push-ups. Don't just shoot for 15 6 times and call it good. Do that, then do as many as you can, once you eat floor because you cant hold yourself up, go to your knees and burn it some more. Try some elevated push-ups too. Do sit-ups and crunchs, leg lifts, flutter kicks, and look for other exercises as Im sure there are multiple forms of terminology for some of the others ones I could list. It will keep a normal workout a little bit more entertaining than just doing sit-ups... and then just doing push-ups. The pull-ups on there is about the only thing I wouldn't mess with. Starting out slow with that is the best, and work yourself up from there. That's if you haven't really done pull-ups before. But just as with push-ups and sit-ups you need to burn yourself out with those too. Get a friend to spot you while you do them, so when your arms shit out you can do more reps.
Really it's all about consistency. You can't just do this off and on and expect great results. It's an 7 day a week thing. And don't forget to hydrate. damn.
3/75 & 1/75 Alumni
Ranger School 09 - 04