A chiseled six pack is probably the No. 1 superficial indicator that you at least try to lift weight once and awhile. From a sports standpoint, a strong and stable core means a more efficient transfer of strength between the lower body and the upper body.

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Whether your goal is to train sport-specifically or not, ab training typically falls into two categories: traditional flexion exercises, including exercises like Sit-Ups, Crunches, Toe Touches and V-Up’s; and anti-movement exercises, including anything from a simple Plank to a more complex Barbell Rollout, single-arm movements or a Paloff Press.

Although bodybuilders since the early 50s (and even earlier) have been using traditional flexion ab exercises, they are generally frowned upon by today’s strength coaches as non-sport-specific and too stressful on the back.

They certainly have their downside, but I believe that traditional ab exercises like Plate Sit-Ups and Crunches still have a place in sport-specific training. These exercises are a great way to build the rectus abdominous—the fancy term for the abs—and to fatigue the mid-section in general.

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The ancient Greeks had a philosophy of the “unity of opposites.” The existence of one thing depends on the existence of another. You cannot have flexion without extension, bending without straightening. You can’t have movement without opposing movement. The pairing of movement and non-movement abdominal exercises in a workout provides the best of both worlds.

Before we prescribe the workouts, let’s break down the anatomy of what is considered the core. Most people falsely assume that it’s just those six little bumps on the stomach that try to come out every summer and disappear every winter. In reality, the core consists of several muscles crossing the front and the back of the torso, and it serves a variety of anatomical functions.

• The muscle that makes up the “six pack” (the one trained primarily through flexion of the torso) is the rectus abdominous.
• Lying beneath the rectus abdominous is another smooth muscle, which is responsible for compression of the abdomen. Whenever you hold your breath and suck in your gut, you are flexing your transverse abdominous. It is responsible for stability through maintaining intra-abdominal pressure.
• The abdominal muscles that initiate rotational movement and side bending include the internal and external obliques. The fibers of these muscles run different ways. The internal obliques cause ipsilateral rotation (rotation to the same side of the oblique muscle), and the external obliques cause contralateral rotation (rotation toward the opposite side of the oblique muscle) and side bending. The external obliques lie on top of the internal obliques, which in turn lie atop the transverse abdominous.
• A muscle not located on the front of the torso but which is just as important for torso stability and strength is the erector spinae. Each one is composed of three different muscles and runs parallel to the spine on either side.

It should now become apparent that your core can move four different ways. It can flex (crunch), it can extend (back bend), it can twist (baseball swing), and it can bend to the side (picking up a bag of groceries). If your core can do each of these motions, it can also also resist each one. This is the root of anti-movement exercises. The goal of these exercises is to stabilize the torso as you resist gravity pulling on your body or an external load in the opposite direction.

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Below are five killer workouts that use traditional exercises and anti-movement pattern exercises together to comprise a complete abdominal workout. Any athlete can benefit from these workouts, from a football lineman to a swimmer to a bodybuilder. They can also benefit anyone who’s looking to get a stronger and more functional core.

You can vary your abdominal training just as much as any other type of training. Training your abs does not excuse you from going heavy or incorporating new exercises frequently. Most people get stuck in the trap of finishing every workout with 50 Crunches, 50 Sit-Ups and a Plank or two, never changing their routine or challenging themselves. Don’t be this person. Be smarter than that, and use your new repertoire of exercises to build a functional and aesthetic core!