I do about 200-400 crunches with a 20 pound weight everyday on a machine.

I was wondering if that is doing more wrong than good to my abs? I'm looking for a six pack, yet not too manish.

I know how you should give muscles a rest for a day before doing them again but is it the same for abs?

i wouldn't give them a rest every other day, but at least once within a 2 week period. however, as you are lifting weights and are doing a large amount of reps, you may want to give them a rest each week. although they don't need as much repair time (24 hours) as a larger muscle such as quads, they still need a rest.

perhaps you might want to try to do some other exercises to 'keep your body guessing'. like do it on a swiss ball instead of a machine, or do v-sit ups (they are supposed to be excellent for abs!)

Have to agree about the v-ups. My 2 oldest girls are cheerleaders and v-ups are on one the many "conditioning" exercises they do after almost every practice and tumbling class...hard to do most tumbing without strong abs. Of course they are also the one they (ALL the girls) complain about the most, just a sign how hard they really are. These are REALLY strong girls.
Just wanted to add that I am NOT a 20-something with a 13 y/o, I'm 33 (34 on the 11th, but I'm not claiming it til then). I got here through the "Recent Forum Topics" on the main page. Okay, back to the old folks home.

The "V-up" sounds really interesting, how do you do it?

from The Core-ect Way to Train (do a search with this name and get a whole list of core exercises) they have it listed as an intermediate core exercise:
V-sit up – Lay on your back with arms extended over your head. Lift the legs and arms at the same time as far as you can until your body forms a V.
*My girls are actually told to reach more for thier feet, and the REALLY hard part-head, hands and feet can't come all the way down.
Yeah, I know. Poor things, but they are the ones who want to be cheerleaders. But you should here them all moan, kind of funny really.

Read this:

http://www.stumptuous.com/cms/displayarticle.php?aid=3

stumptuous.com has pretty much saved me from myself where strength training is concerned! Those v-sits and other Pilates types moves will really help get your core muscles in shape. If fact I’ve heard so many bad things about that ab-crunch thingy machine at the gym from sources/people I trust about such things that I’ve given it up all together. I have a stability ball and rely on Pilates and yoga for my core strengthening now. And I can really tell the difference, my core and overall strength has improved so much faster and better since I’ve stepped away from the weight machines.

sorry to have gone OT on you trns. i should have said "if you aren't getting the results you are wanting after doing your current routine for a decent period, perhaps look at other versions of ab work". It might be what you are after. I did read that a good way to do your abs is every day you weight train. In an ideal world you should have one day off per week at least so it would give your abs a rest then, but still be worked throughout the week.

Do you remember the first time you really worked your abs and the next day you could really feel it? Do you still get that feeling with your current workout? If not, then I believe it might be best to swap to another type of exercise to surprise your muscles and get them out of complacency.

But then again, i could be completely off base

Thank you so much everyone. Every bit of info helped.
I need to do something before i gain more!

Remember...abs are made in the kitchen, not the gym...your abs are like any other muscle and need 48 hours to heal especially if you are using additional weight resistance.

"As I've mentioned, many folks do too high a volume of ab work at too low an intensity. A good frequency for direct ab training is two to four times weekly, with perhaps one weighted ab exercise per workout, done for 2-4 sets of 8-15 reps. Put your heavy ab training at the end of your workout so that you don't fatigue the midsection too early and compromise torso stability (though you can use lighter ab work, such as standing pelvic tilts, as a warmup for something like squatting). These are general guidelines, of course, and you can adjust them to suit your needs. But bear in mind that as always, more isn't better, better is better!"

http://stumptuous.com/cms/displayarticle.php?aid=3