Shhhh… we’ve got a secret, and it’s a doozy.

It’s all to do with getting that sleeker, slimmer waist – the one that people spend hours upon hours angrily doing crunches trying to achieve. But the secret, in fact, lies in an often-overlooked set of muscles sitting deep within your core. They’re called the transverse abdominus muscles, and have been called everything from the “abdominal corset muscles” to the “body’s natural girdle”. Sometimes, they’re even referred to the “Spanx of the Body”!

Working out core muscles like the rectus abdominus or obliques tend to make your belly jut out, without actually reducing the size of your waist. And that’s where the transverse abdominus comes in – not only do these wonder muscles tighten your midsection, they also help with stability, posture, breathing, and lower back strength. The question is: is there anything the transverse abdominus muscles can’t do?

With that said, let’s take a look at five essential transverse ab exercises, to get that lean, slender look you’ve always wanted.

1. Plank

Not surprisingly, the plank is one of the best transverse abdominus exercises around. The keys to getting results from the plank are time and form. You want to hold your plank for as long as you can, increasing over time, while always maintaining proper form. When your form starts to break down, that’s a good sign you’ve had enough and it’s time for a rest.

To perform the plank:

• Begin laying face down on your stomach
• Lift yourself up onto your elbows and toes (or knees as a less intense option)
• Keep your spine flat, with your buttocks in-line with your body
• Try to stare straight ahead of you, making sure you don’t strain your neck
• Hold for 5-10 seconds to start, then lower yourself back down
• Gradually increase your duration by 5 seconds with each rep
• Repeat 3 times

2. Supine Leg Extension

This powerhouse move reveals just how important the legs can be for strengthening your core. Our legs not only act as anchors for balance, but as counterweights, working the core while you stabilize.

To perform the supine leg extension:

• Begin by lying on your back, knees bent suspended above you
• Extend one leg and hold it up 4 inches
• Raise your opposite arm above your head
• Hold both your arm and leg in this position for 2 seconds
• Repeat on opposite side
• Do 15 reps each side!

3. Glute Bridge

This multi-muscle-hitting exercise hits the transverse abdominus, but also several parts of the lower body, including the glutes and hamstrings. Do this right, and often, and we guarantee you will feel this.

To perform the glute bridge:

• Lay on your back, with knees bent and feet on the floor
• Place your feet as close as you can to your glutes
• Using one leg, lift your buttocks off the ground, thrusting your hips upward and extending the leg of the non-planted foot
• Engage your quads
• Hold your position for 1-2 seconds and release
• Repeat this exercise 10x, then switch to the other leg, then repeat on each side again for 2 or 3 rounds total

4. Quadruped Lift

This exercise, lovingly referred to as the bird dog, is similar to the supine leg extension, but reversed. The trick here is to keep your head straight and eyes looking forward, not on the ground as most people tend to do.

To perform the quadruped lift:

• Position yourself on your hands and knees
• Extend one leg directly behind you, keeping it as straight as possible
• Extend the opposite arm directly in front of you, also as straight as possible
• Hold for 5 seconds
• Switch to the opposite arm/leg and repeat
• Repeat each exercise 10x on each side for a total of 3 rounds

5. Russian Twist

You may not know the name, but you’ve definitely seen the Russian twist performed, usually by some svelte-looking gym hero. Now it’s your turn. This is one of the hardest, most effective transverse abdominus exercises you can do. Let it be known: you WILL be sore afterwards.

To perform the Russian twist:

• Start in a seated position
• Raise your feet several inches
• Lean back at a slight angle
• Intertwine your fingers
• Twist from side to side, making sure to keep your core tight
• Your goal should be to touch your knuckles on the floor with each rep
• Repeat 30x, touching each side 15x

Phew! That’s a lot. Don’t believe us? Try it. With these powerful transverse abdominus ab exercises, you will access your core, your deeper core, your super deep core, and everything in between. And when you start focusing on these amazing corset muscles, you’ll see the kind of results you’ve been waiting for.

But what about everything else? If you want a more full-body experience from the comfort of your living room, sign up for a 7-Day Free Trial with Studio SWEAT onDemand. With hundreds of streaming classes available, including abs, sculpting, cycling, yoga, TRX, Pilates, and more, you’re on your way to becoming a hard-core gym hero.