Yes they are but you should warm up really well before and start doing crunches right after the other exercise; it will burn more!.
Situps and crunches are good abs exercises.
it is always good to get the exercise with crunches but does not help get abs. it will help your stomach get tougher though so the more you work on it the tougher your stomach will get, but you wont have abs!
you cant. but you can get abs by doing bicycle crunches and regular crunches.
Crunches will help you to get abs however, you will not be able to see them without losing weight. If you have a layer of fat over your abs, no amount of crunches will give you the abs that you are looking for.
Yes, cable crunches are an effective exercise for targeting and strengthening the lower abs.
A good workout program that focuses on the abs will significantly strengthen your core. The best programs put emphasis on crunches and sit-ups.
Dancing believe it or not (of course using your abs. not like fist pumping) crunches and plank are excellent ones.
Itz very possible
Do crunches daily or get a hard working physical labor job. Or both.
generally exercise and eating right. don't just do crunches, use your lower abs and upper abs as well as your obliques.
Mainly just the abdominal muscles.
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.