[LCpl Lamm]

Well, when I am doing 400 a day, I don't get hurt, and if I do, I rest for a day or two or however long it takes for them to heal. So, would it be wise or bad to do sit-ups everyday? For sit-ups, and pull-ups, I am working on doing 100 sit-ups in 2 minutes or less and doing 20 consecutive pull-ups.
Come to think of it, when I say I do 400 sit-ups a day, they're actually crunches. I have a hard time finding someone to stand on my feet, and I have a hard time finding something that will hold my feet down, like a couch thats low to the ground. I think I found something that will hold my feet down though, so I will probably do 4-5 max sets of actual Marine Corps sit-ups everyday, since my max set right now is low. And, since 405 max sets of sit-ups won't equal to 400, which they won't, not now, I will just finish out the rest of the reps with crunches.
Am I doing too much? I've heard that as long as you are not hurting yourself, and you are not working a muscle group to death, and not working a muscle group when it is sore/hurt and needs to heal, you can exercise away.
Thanks,
Lamm