It depends on which ones you do. some will really do nothing
Hip Hop Abs and P90X
Sit Ups
No, calves are not slow-twitch fibers. I would actually give 2 days between workouts for fast-twitch fibers though. They require that much time to fully repair.
The Firm has some great DVD workouts that focus on the abs. Pilates is great for te abs too and there are tons of Pilates DVD's on the market.
Workouts that are good for building ab muscles are sit ups, crunches, and planking. Planking is actually an exercise that works the whole body.
absolutley, swimming is one of the best total body workouts there is.
If you "is" a teen. Wow. try to actually work out,
work on a different part of your body every day
Yes, intense abdominal workouts can potentially increase the risk of developing a hernia, especially if proper form and technique are not maintained.
There are several abdominal workouts with different names and poses. Some popular exercises are bicycle, captain's chair, ball crunch, and leg crunch.
There are many great workouts that will help you get six pack abs, but my favorite is a bicycle crunch. It works all your abs and at the same time it gives you that finishing touch of the V cut. This answer is good too but you did not list the workouts that the person asked for in the question. I think workouts like Pilate's and crunches and stuff like that should help. going for a swim is good ab workout plus its a hole body workout and it will help you cut down fat in your abs and also doing around 15 minuets of skipping ( with ropes) will help tone your abs if you flex well doing it .
That is a very good question. And my answer is that you shouldn't work your abs out at this age. You need to fully go through puberty first before working on your abs. If you have gone fully through puberty, than work your abs the hell out. Good ab workouts are leg lifts, crunches, sit ups, push up, and side to side ab crunches. But don't just workout your abs, workout your biceps,legs,back,and triceps. If you get veins on your abs and other body muscles,that is very good.