The rectus abdominis is the muscle you think of when you think "abs." It's the outermost abdominal muscle, and runs vertically along each side of your abdominal wall. The transverse abdominis is the deepest muscle of the abdominal wall, which means it's closest to your spine, and basically wraps around your torso between your ribs and your hips. The oblique muscles run along the sides of your torso, and there are two sets: internal and external. The internal obliques lie above the transverse abdominis, and then the external obliques are on top of those (they're the most superficial of the bunch). There's also a handful of other smaller muscles in this area—what we call the core—that work to stabilize the spine and allow us to bent and twist and lift without hurting ourselves.
Warm up and cool down for 5 to 10 minutes. Go for a brisk walk or jog, do jumping jacks, run in place, or jump rope at the start of your workouts. Moderate aerobic exercise will increase blood flow to your muscles, which reduces your risk of injuring yourself. When you finish working out, cool down for 5 to 10 minutes to help your muscles recover.
Lie down on a mat and place your hands behind your head, gently supporting your head with your fingers without pulling. Bring your knee up to your chest, while rotating your upper body to meet your knee with the elbow of your opposite arm (see photo). The opposite leg will go straight out. Switch to the opposite side, “cycling” the legs. Do one to three sets of 12 to 16 repetitions each.
The next time you're at the gym, take a stroll. "The dumbbell farmer's walk may be one of the most underutilized exercises, and it's also one of the simplest to do," says Jack. Besides making it easier for you to carry heavy things—like luggage or those cases of beer for this weekend's party—the ab exercise challenges your core muscles to endlessly stabilize as the load shifts with each step. Plus, it will strengthen your grip, forearms, deltoids, and trapezoids—areas often neglected during workouts.
Do it: Stand with your feet hip-width apart and hold a dumbbell in your right hand, palm facing inwards towards the torso. Keep your back straight, activate your core, and then bend to the side as far as possible—but only at the waist. Hold for one second at the bottom of your range of motion, and return to start for one rep. Do between 12 and 20 reps for one set.
Muscles exert higher EMG tension when they are contracting eccentrically (lowering the resistance) versus raising it; but the problem with most exercises is that the amount of weight you can lower is limited by how much you can lift positively (concentric work). This exercise compensates for the problem by changing the leverage during the lowering (eccentric) phase of the exercise.
Consuming more fat in your diet will actually help curb cravings after you’ve reduced your carb intake. “Fats help curb hunger because body takes longer to break down, use, or store fats,” he says. Hormones also play a role, especially when it comes to muscle-supporting testosterone. “Fats are needed to create and balance out hormones in our body to function normally,” McComsey adds.
When you're doing exercises to strengthen these muscles, think of the abs and core as one unit. Even when you do exercises that recruit more of one muscle than the others (for example, side planks that really fire up the obliques), you'll notice that you still have to engage your entire midsection to do them right, which is proof that these muscles are never working completely alone. It's important to show equal love to all of the muscles of the core so that this unit can power itself properly from all angles.
But there's science behind this buzzkill. The rectus abdominis — the muscle that makes the stomach look defined as hell — is typically covered by fat (because that's how humans are made) and isn't affected by things like crunches and planks. "You can work your abs all you want, but if you have a layer of fat over them, the 'pack' can’t be seen," Ball says. And FWIW, that's not a bad thing or something to feel bad about. "It’s very unrealistic for most people to have body fat percentages low enough to see the abs."
"My goals six years ago was to 'get abs' and I used to think cardio and crunches would get me there. But it wasn’t until I started lifting weights and varying my abdominal exercises that I started to see a major change. You don’t realize how much you use your core muscles in order to perform powerful rapid movements like deadlifts!" — Shante Franca, @shantefranca