You've heard it a million times: Abs are built in the kitchen. We're not trying to refute that. It's true, whether you want to let yourself believe it or not. 

But, it's also true that what you do in the gym makes a big difference, too. You can't spot treat, but you can do workouts with an emphasis on your core to help speed up those mid-section results. To do that, you want to make sure you're doing the best possible abs exercises that will help you reach your goal faster.

In addition to choosing the right moves (the ones below are a great place to start), you need to make sure you're continuously making them harder, as you begin to see changes in your body. "Two of the keys to building a good core are making sure that the exercises are suitable for your level—and continuing to progress,” says trainer Noam Tamir, C.S.C.S., founder of TS Fitness in New York City.  “Otherwise you use your hip flexors or put unnecessary stress on your lower back.”

And getting injured is not going to get you any closer to seeing those abs. So, Tamir has provided a tip for how to progress each one of these awesome six-pack-making moves. Try level one of each of the following four moves first—once you master them, make it harder with the progression given. 

1. RKC plank

"This exercises requires maximum muscle contraction in a plank position," says Tamir. 

How to: Get into a position on your forearms and toes with your elbows under your shoulders. Drive your elbows towards your hips and pull your toes towards your hips contracting your whole body. This will work your core along with every other muscle in your body. I recommend doing this in clusters (sets within sets) of 3 with 10-20 second holds.  

Make it harder: In a plank position extend one arm directly in front of you without letting your hips shift. Return it back and then alternate with the other arm. Do 3 sets 8-10 reps on each side.

2. Rollouts

"Rollouts are another exercise that work the anterior core and give you a lot of bang for your buck," says Tamir. 

How to: Start in a kneeling position with a Swiss ball on the floor. Your arms should be straight in front of you and palms on the ball. Slowly push your hip first forward maintaining a straight spine the whole way through the movement till your body is parallel with the floor and then return back keeping the same neutral spine. Do 3 sets of 10-12 reps. 

Make it harder: From a standing position place a super band around you waist. Lean over and roll out keeping your body parallel to the floor. Return back to the starting position. Do 3 sets of 10-12 reps.
 

3. Reverse crunch

"There is no such thing as your lower abs but that being said the reverse crunch is one of those challenging exercises that definitely gives you a great burn in the lower region of your core and works that transverse abdominal area (the deep core muscles around your waist)," says Tamir. 

How to: Start from the floor on your back with your arms anchored to a heavy kettlebell or dumbbell overhead about head width distance apart. Lift you legs off the ground with your heels towards your butt. Press your hips up then bring your knees towards your chest rounding your lower back. Then slowly return back to your starting position. Do 3 sets of 8-12 reps. 

Make it harder: This one is a killer and should be used only for advanced individuals. Many people think that they can just lift their knees up and can do the exercise but it puts strain on their hips. Hanging in a bottom static pull up position tuck your pelvis and slowly lift your knees to your chest getting them waist high and slowly returning them down. Do 3 sets of 8-12 reps.

4. Kneeling band rotation

How to: In a keeling position begin with an elastic band anchored to the side of you at about shoulder height. Extend your arms straight in front of you holding the band in an interlocking grip so there is tension in the band. Rotate your torso while keeping your hips and lower body straight. Return back slightly past the midline of your body and repeat. Do the same for the other side of the body. Do 3 sets of 12-15 reps each side.

Make it harder: This exercise will require more dynamic movement and stabilization because you are in a standing position with more joints. Begin with an elastic band anchored to the side of you at about shoulder height and your feet about shoulder distance apart. Extend your arms straight in front of you holding the band in an interlocking grip l so there is tension in the band rotate your torso while keeping your hips and lower body straight. Return back slightly past the midline of your body and repeat. Do the same for the other side of the body. Do 3 sets of 12-15 reps each side.