The right exercises make all the difference in turning those abdominal muscles from flab to fab. There are many great workouts to flatten the tummy, but some are more effective than others. The best abdominal exercise will work the entire abdominal region while strengthening and protecting the back at the same time. We have four of the best crunches to get your abs in peak condition before swimsuit season hits.

The Reverse Crunch

The reverse crunch is one of the most effective abdominal exercises for the rectus abdominus; the long muscle in the center of the abdomen that stretches from the pubic bone to the lower ribs. The reverse crunch is most frequently performed lying on the floor with the legs raised at a 90° angle and the arms at your sides. You have the option of pointing the legs straight up or bending them at the knee. With slow, controlled movements, lift your legs and hips of the ground, and then lower them again.

The Bicycle Crunch

This exercise begins in a similar position to the reverse crunch. Lie on the floor with your arms locked behind your head and your legs raised at a 90° angle. Instead of lifting your legs to the ceiling, move them forward in an alternate motion, as though you were pedaling an imaginary bicycle. As you are pedaling, twist and bring the left elbow to touch the right knee that is bending towards your middle. Reverse as the left knee moves toward the center of your body. This abdominal crunch is another excellent option for working the rectus abdominus muscle.

The Captain’s Chair Crunch

This exercise requires the use of a captain’s chair, which can be found in most fitness centers. The device looks like a raised lifeguard chair (without a seat), with armrests and handles on either side. First, raise yourself onto the captain’s chair, with your arms sitting on the armrests and your hands gripping the handles. Your legs should dangle underneath you. With slow, controlled movements, raise your legs up to your waist at a 90° angle. This crunch will also work the rectus abdominus muscle, but will give the obliques on the sides of the abdomen a workout as well.

The Balance Ball Crunch

The large balance ball is a vital piece of equipment for many workouts today, including those designed to work the abs. When you shift your crunches to the balance ball, you work all of your abdominal muscles and strengthen the lower back at the same time. To perform this exercise, lie with the center of your back resting on the balance ball, your feet comfortably resting on the floor and your hands locked behind your head. Slowly raise your upper body up as far as you can and then lower again.

With an effective workout repertoire like this one, your abs will be in top shape in no time. In addition to flattening the tummy, these exercises can strengthen the lower back and prevent future back problems. Repeat these exercises every other day without fail and you will be sporting your sexy new six-pack this summer.