Flutter Kicks Have Big Ab Benefits. Here's How to Do Them for the Best Results

With so many ab exercises to choose from, some are bound to get lost in the shuffle. However, there's one you should be sure to keep track of: flutter kicks.

"They're a low-impact exercise that can be done anywhere with minimal equipment and space," says Brett Durney, CPT, co-founder of Fitness Lab boutique gyms in London.

What's more, they hit your abs from many angles, helping you build a rock-solid midsection from the inside-out. And if you're not ready for the traditional version (yet), there are ways to modify flutter kicks to fit your body.

Here's everything you need to know to nail this awesome ab exercise.

• ​What is a flutter kick?​ This challenging ab exercise can be spotted in many Pilates classes and strength routines. You perform the move by lying on your back, lifting your legs off the ground and "fluttering" your feet in an up-down motion.
• ​What muscles does the flutter kick work?​ This abs strengthener target your rectus abdominis (six-pack muscles) as well as your deep-lying transverse abdominis and obliques for stabilization. They also train the lower back, hip flexors and quadriceps, says Jody Braverman, CPT, a certified personal trainer and weight-loss coach
• ​Who can do flutter kicks?​ They are generally safe and accessible, though there are groups who may want to find an alternate core exercise. People who are pregnant or have back pain should avoid this exercise unless their doctor or physical therapist has given them the go-ahead.

Nailing flutter kick form is critical to really engaging your abs and keeping stress out of your lower back. Here, Daniel Richter, CPT, powerlifting trainer and co-founder of StrengthLog, show's how it's done.

The motions may be small, but you're building serious core strength and stability with this abs move. "The up-and-down motion has your abs working hard to control your legs, pelvis and core," Richter explains.

Plus, simply holding both legs off the ground takes a good amount of core strength. And a strong core offers many benefits, including injury prevention, improved posture, and greater stability and balance, Durney says.

Flutters are especially great at hitting the lower portion of your ab muscles, an area many moves like crunches and planks don't hit as much.

Some folks worry that performing ab exercises like flutter kicks results in tight hip flexors. But when it comes to tight hips, hip flexor-strengthening exercises like kicks aren't necessarily the problem. They might be part of the solution.

Working your hip flexors increases blood flow to the muscles, helping to make them warm and pliable, Durney says. This can help improve hip mobility and ease tightness.

Flutter kicks are sometimes referred to as scissor kicks. But they aren't ​quite​ the same thing.

Scissors have one key difference that sets them apart from flutters: widening the legs into a "V" shape before bringing them together and crossing one leg over the other.

So, instead of fluttering your feet up and down throughout your set, scissor kicks involve alternating that "V" shape with crossing one leg over the other, making sure to alternate which leg crosses over the top.

Thankfully, there isn't much difference between flutter kicks and scissors, as they essentially work the same muscles. "There may be some small stabilizer muscles that are more active in scissor kicks, but it's going to be minimal," Braverman says.

Cab't do flutter kicks? If you have a hard time keeping your back from arching, perform the move from a bent-leg position instead, Durney says. Over time, you can straighten your knees bit by bit.

Here's another great way for beginners to do flutter kicks, By keeping one heel on the floor at all times, you wind up lifting only half the weight you do with standard reps. Plus, you don't need to work as hard to stabilize your lower body, Richter says.

To make the exercise more challenging, simply add some ankle weights. Thanks to the extra weight coming through your legs, your core will have to work harder to keep everything in place, Durney says. Start with light ankle weights — 1 pound per side should do it, Richter says — and progress from there.

Holding a weight overhead lengthens your core muscles, and increases the amount of work on your upper abs, Durney says.