In a short answer, NO. Spot reduction is a myth. You cannot specifically remove fat from a specific location, such as doing crunches to lose belly fat. This is because you lose fat all over your body. That means that while crunches are good to build your ab strength you should burn off the fat covering your abs to make them visible.
Truth is that the only ab-specific exercise I do nowadays is actually the “plank”.
I’ve built up enough strenght to do it for a few minutes. Now I am adding weight, I do about 1 minute with 60 lbs in my back with plates that a friend helps me put there.
The rest of the time I focus my energy on fat loss or building muscle. You won’t get “ripped” doing cardio and ab workouts, unfortunately. You have to strengthen and build some muscle too. That means eating more first and training with heavy weights to build up strength and muscle size (you’ll gain some fat as well).
Then you have to remove calories, keep strength training and add cardio to your routine. When I’m cutting weight (losing belly fat) I train with weights 3 times per week and do HIIT cardio 3 times per week alternating days.
Monday: Back, Traps, Calves
Tuesday: Burpee HIIT (30 second work / 30 second rest)
Wednesday: Chest, Shoulders + Planks
Thursday: Sprint HIIT (30 second work / 30 second rest)
Friday: Legs, Biceps, Triceps
Saturday: HIIT (30 second work / 30 second rest)
Sunday: REEEEST A LOT!
This is a typical cutting week for me. Sometimes I’m off doing things and I’ll have to do a quick Tabata workout in the morning. I always do burpees with tabata because I can do it in 4 minutes at home, with no equipment or space.
So, all in all. Crunches are good at first, then you should move to planks and adding weight to them. Go for a 1-2 minute hold. This makes your abs thicker and deeper, very nice! It doesn’t burn fat, but makes them nicer once they appear 
All the while you need to be strength training to build muscle and doing cardio to lose fat. I hope you really start to work hard, becuase it’s not easy to lose belly fat if you don’t know how. If you know how, then it’s very simple, you just have to do the work. Nothing is free, especially not abs! There are ways to do it “faster”, such as I’ve outlined here. You can probably cut the time from 6 months to 3 months by doing it this way.
Good luck,
- Chris
