The hallmark of fitness is a nice six pack, because it not only represents a certain level of effort in the gym, but also maintaining a relatively low bodyfat percentage.

For this, both diet and exercise play important roles, but the reward is a set of abs that are the envy of everyone you know. Here are six ab exercises to get you that highly sought, but rarely achieved, holy grail; the six pack.

The Workout Program

Perform one set of each exercise 3 times a week. These exercises are of sufficient difficulty that one set will be a good start. Shoot for a rep range of 8-12. Once you can consistently get 15 reps with good form, and still make it through the workout, add another set.

Rest: 90-120 seconds

1) The Pike

Lie faceup with your legs straight, arms at your sides, palms facing down. Raise your legs and torso 45 degrees off the floor. (You should look like a "V".) Reach your hands alongside your legs as high as you can without rounding your back.

Key Point: This one is tough, but focus on contracting the abs to move your body.

2) Cable Side Bend

Attach a D-handle to a low-pulley cable and stand so your left side faces the weight stack. Grasp the handle with your left hand, keeping your arm by your side, and place your right hand on your hip. With your head facing forward, slowly bend to the left. Return to standing, repeat for reps, then switch sides.

Key Point: Granted, obliques aren't abs, but this movement is an integral part of any ab workout.

3) Weighted Crunch

Lie faceup with your knees bent and feet flat on the floor. Extend your arms toward your knees, holding a lightweight plate with both hands. Keeping your arms extended, slowly lift your head and shoulders off the floor moving into a full crunch.

Key Point: Again, focus on contracting your abs to do the work. Use a light weight and anchor your feet if needed.