You have four ab muscles, not just a six pack: the rectus abdominis in front, the internal and external obliques on your sides, and the transverse abdominis, a deep sleeve of muscle that holds everything together.
Listen: when most people think of abs, they only think of the six pack. That’s one of four. A lot of the workouts I used to do only worked that one muscle group, and I’ve since learned it’s important to work all of them.
The 4 ab muscles
- Rectus abdominis: the six pack in front. Crunching motions.
- Internal obliques: on your sides. Rotation and core stability.
- External obliques: on your sides. Twisting and bending.
- Transverse abdominis: the deep core. Holds everything together.
1. Rectus abdominis: the six pack
The rectus abdominis is the six pack, the muscle in front. When most people think of your abs, this is what they’re thinking about. It’s what you see when someone lean has a six pack, and it’s the muscle crunches and toe touches train. But it’s only one of the four.
2 and 3. Internal and external obliques
Your obliques are on your sides, and there are two parts: the internal obliques and the external obliques. They handle twisting and bending motions. It’s important to train your obliques too.
4. Transverse abdominis: the one you can’t see
You can’t see the transverse abdominis from the outside. It’s a sleeve of muscle beneath your rectus abdominis that holds everything together.
When you do a plank, your transverse abdominis is what enables you to hold it. When you do a squat and need to stay stable, it’s what holds it all together. And when you do a vacuum and suck your stomach in, that’s your transverse abdominis doing it.
If you still have belly fat, this is the one to train, because it pulls your waist in and makes your stomach look smaller. Here’s how to do a stomach vacuum.
How to train all four
The workout I used to do for years only hit my six pack. The one I do now hits all the major muscle groups in your abs with three exercises: toe touches for your rectus abdominis, V-sit twists for your obliques, and Spiderman planks for your core and obliques. That’s my 1 minute ab workout, and you can do it at home with hardly any equipment.
The ab wheel is another great option, because it works your rectus abdominis, transverse abdominis and obliques at once. Here’s why the $17 ab wheel beats every crunch.
That’s why I train all four muscle groups now, and why you should too.
Want to see what you’d look like with six pack abs? Generate your free AI transformation.
This is general fitness information, not medical advice. Some images in the video are AI-generated visualizations, and they’re labeled.
