The Science Behind the Best Ab Workouts

Carving an enviable six-pack isn't an easy feat — which is too bad, because it seems nearly everyone wants a defined set of abs. But too many people view a sculpted midsection as a kind of status symbol, reserved for the genetic elite or those who spend more time doing ab workouts than anything else. And that's simply not the case.

Yes, your genetics and diet influence how much muscle definition and how little body fat you have around your midsection. But here's the thing: Everyone has abs — regardless of how well you can see them — and that means everyone can build stronger midsections.

You might have to relearn a few things (nothing worth having ever came easy, right?), but by incorporating the principles below and trying some new exercises, you can create the ultimate ab workout.

Ever wonder why sit-ups became such a popular exercise? Often, anatomy books state that the purpose of your abdominal muscles is to flex your spine. As a result, many think that by creating a "crunch" type movement, you'll build your abs the way nature intended.

Unfortunately, most anatomy books are at least 35 years out of date, says Mark Comerford, a researcher, physical therapist and founding director of Kinetic Control, a consulting agency that assists physiotherapists. While your abs ‌do‌ flex your spine, that's only one part of their job.

Your core is more than just your abs — it includes layers of muscles that help support your back, hips, butt and stomach.

Your core muscles also help:

• ‌Create movement:‌ If you're standing upright and bend forward at your waist as fast as you can — like a boxer ducking a punch — you'll feel your abs activate.

• ‌Counterbalance movement:‌ If you were to start leaning backward from standing, you'll again feel your abs activate, but this time in a different way. Your abs are doing the opposite of what anatomy books tell you. Rather than flexing your spine, those muscles are fighting the extension of your spine to keep you from falling over.

• ‌Resist movement:‌ Imagine you're standing upright with your arms reaching straight out at shoulder height, hands locked together. If a friend were to push your arms to one side, how would you resist their efforts? Your abs.

• ‌Rotational movement:‌ Imagine you're facing forward and twisting your torso to the right. Your core helps you rotate your torso while keeping your spine and pelvis safe.

In order to build an effective ab workout, it's crucial to challenge your entire core in all of these different forms and motions. That's because almost every movement you do — both during your workouts and in your daily life — engages your core in some capacity, according to Harvard Health Publishing.

Press a weight overhead? Your core is engaged. Stand on one leg? Your core is working. Struggle during a tough exercise and "cheat" a little on your form? Yep, you'll probably feel your core coming to the rescue.

It's the ultimate question for fitness fans: What's the best ab exercise? Bicycle crunches, captain's chair (aka knee raises) and stability ball crunches are three of the most effective ab exercises, according to widely cited 2001 research sponsored by the American Council on Exercise (ACE).

Here's how to do those some of those moves.

While endless crunches might not be the best approach (see below for more on that), if you're strategic about the ab exercises you choose, you can create an incredibly effective core workout.

Incorporating a stability ball is an excellent tool for strengthening your midsection, and it can be used in lower-ab exercises and oblique-sculpting moves.

Adding this tool to your ab workout at home has benefits for your entire core because it helps you target all the functions of the trunk, including flexion, extension, side-bending and rotation, according to the ACE.

Try this four-move routine the next time you need an ab workout at the gym or at home.

In recent years, crunches and sit-ups have gotten a bit of bad press, as fitness experts and rehab professionals began speaking out against the exercise. Stuart McGill, PhD, a spine researcher at the University of Waterloo, found indications that performing too many crunches (or doing them too frequently) could cause a person's spinal discs to push out too far, causing pain and potentially a herniated disc.

Claims like this regarding the effect of crunches are highly debated. Carl DeRosa, PhD, founder of DeRosa Physical Therapy, says your body position isn't responsible for putting pressure on your discs — it's how tightly you squeeze (or compress) your muscles.

Other experts, like spinal researcher Michael Adams, PhD, say a person's discs can actually strengthen (like your muscles) and potentially become more resilient to injury as a result of doing ab exercises like crunches properly.

The bottom line: If you have a disc-related injury, crunches might not be the best exercise for you. But for healthy athletes, a few sets (not hundreds of reps) of well-performed crunches can help activate your abs. Just don't rely on them as your sole form of ab exercise.

So, can you just do a bunch of bicycle crunches, hanging leg raises and Swiss ball crunches and wake up one morning with six-pack abs? Not so fast. There's no such thing as "the best ab workouts for quick results." Ab exercises alone won't banish belly fat to reveal amazing abs underneath — you still need to be burning more calories than you take in to shed body fat.

Chiseling your midsection requires a concerted effort that involves overhauling both your workouts and your nutrition (and often, a little help from your genetics).

First, you'll need to clean up your diet and cut calories to reduce your overall body fat percentage. That often means limiting highly processed foods and alcohol and prioritizing lean protein, fresh vegetables, complex carbs and healthy fats.

Next, you'll need to make sure you're doing cardio. The higher the intensity, the more calories you'll burn. You can either opt for longer, steady-state bouts (like going for a long run) or shorter sessions of high-intensity interval training (HIIT). And lastly, yes, you'll need core-specific exercises, like planks, bird dogs and leg raises.

There is no one "best" exercise to lose belly fat, and reducing belly fat requires more than exercise. You can't spot reduce belly fat. Rather, you'll lose body fat all over with a combination of regular physical activity, a nutritious diet and other healthy habits like getting enough sleep.

‌Try one of the workouts below:‌