When I was a child, the big debate about ab training was whether to do sit ups and crunches. The trend was moving towards crunches, because they involve an actual lengthening and shortening of the rectus abdominis, which you probably know best as your 6-pack (or, if you’re genetically gifted, your 8-pack; or, if you’re in your off-season, your keg). Trunk rotation was becoming popular, too, as a means of training your obliques, also known as your “what the hell, I have abs on the side of my abs?!”
But about a decade ago, things started to change. Fitness became increasingly “functional” (ignoring the fact that looking hot to attract members of the opposite sex is technically a function), and somehow “doing the groceries” became a major selling point to exercise. As I pause and reflect, especially on the number of times I’ve made some kind of grocery reference to explain why a certain exercise is good and another is bad, I wonder how a decade’s worth of personal trainers almost unanimously came to the conclusion that groceries and other mundane aspects of life could be categorised along with the fun, exciting, empowering, sexy framework we were meaning to promote.
As this shift took place, anti-extension and anti-rotation became the big thing. Instead of crunches and Russian twists, planks and side planks started becoming popular. Which was all well and good, until we all got to the minute mark on each exercise and asked: “Is that it?” For a while there, Pilates and yoga was getting so popular that guys seemed to do it for reasons other than checking out 20-something year old girls in yoga pants. Around this time, “deep core muscles” started becoming popular, which we all took to mean that underneath our 6-packs were half a dozen more 6-packs created when our livers, gall bladders and short intestines do planks and crunches of their own.
While the 24-year-old guys were side-planking in an opportune position to perve on 24-year-old girls who were somehow working their cores by being in a pretzel stretch, 17-year-old boys were stacking 3 blue plates on their backs while planking and 17-year-old girls were learning about Kegel exercises from Cosmo.
Meanwhile, everyone was saying that if you wear a belt you won’t use your core and you will break your back. Silly powerlifters.
So, what the nut is going on, and what can you do about it?
First thing to know is that all of the above worked to some extent. Yes, all of it. Flex, rotate, avoid flexion or rotation, wear lycra, use bodyweight, use added weight, strap a tight belt around your waist or avoid belts altogether. All of it works.
The trick, then, is not in finding the one and only best way to use your abdominal muscles, but knowing which methods work best at a given moment. Let’s get down to the basics. Watch out, you’re about to get hit with some sciency stuff.
Abdominal muscles and their functional anatomy
Let’s get into some base anatomy. It turns out that knowing what things are where kinda helps in figuring out how to use them. We’ve already mentioned rectus abdominis. Though normally associated with a 6-pack, it can really be any number of muscle segments packed in there. It isn’t even always the same number on each side (left and right), and if the structure is uneven there’s not much you can do about that. Rectus abdominis attaches from the medial section of the ribs down to the pelvic bone, which gives rise to use in trunk flexion, thus why crunches have been a popular exercise for the muscle.
As an interesting side-note on the rectus abdominis muscle, the general attitude is that the more segments, the better. As I noted above, you can’t change how many segments are actually there, or where the segments divide. You can however change how much fat is covering the various segments. What may come as a surprise is that more segments do not make the abs stronger. In fact, every segment weakens the leverage and blunts the force that the rectus abdominis can exert between the ribs and the pelvis. So if you have a 10-pack, you might like super cool, but your abs are effectively less powerful for it. And if you only have a 2-pack, you might look like a deceased rapper, but but your abs will be super powerful because of it.
To the sides of rectus abdominis, you have four oblique muscles: two per side; one of which is external and the other internal. The external obliques attach from the lateral edge of the ribs down onto the lateral edge of the rectus abdominis, all the way down to the pelvic bone. This means that it’s pretty hard to load up rectus abdominis without at least activating the external obliques. Underneath, the internal obliques run in the opposite direction, starting along the edge of rectus abdominis and splaying out across the ridge of the pelvis.
Underneath all of these muscles is one really freaking big muscle that you probably didn’t know exist. When we talk about “deep core muscles,” we’re usually only referring to one muscle, and it’s this one. The transverse abdominis, like the rectus abdominis, goes all the way from the medial ribs down to the pelvic bone. You might think it has the same function as rectus abdominis, then. You’d be wrong. You see, the whole of rectus abdominis spans from the ribs to the pelvis, which is pretty impressive. Transverse abdominis? It laughs at rectus abdominis and calls it an amateur, because its anchor point between the ribs and pelvis is merely its origin point. From there, it wraps all the way around the body and inserts into the spine, leaving the rest of the abs behind.
Then we all proceed to forget that it exists, not use it, and wonder why we keep hurting ourselves.
The fibres of rectus abdominis run straight up and down, which means that as our motor neurons punch electricity into those fibres, they contract, pulling the ribs and pelvis closer together. The fibres of tranverse abdominis, on the other hand, run horizontally, from the midline of rectus abdominis around to the spine. When we light up those fibres and activate our deep core, they shorten in a pattern much like tightening up a girdle. Or a lifting belt (hint, hint). They squeeze in tight around our internal organs, and transverse abdominis ends up acting like a corset to make us a size smaller. Sadly, it doesn’t go the extra mile and boost our clevage.
Down south, we also have our pelvic floor musculature. I won’t go into as much detail about pubocoxygeal muscles, because when it was time to learn this stuff in my days as a student, we all giggled and blushed too much to get our exercise science right. I remember something in the textbook about how to massage the area, but have strictly refused to apply that knowledge to clients, because I don’t run that kind of business.
The cue that’s traditionally given to women in how to activate their pelvic floor is to tighten the area like you’re trying to hold in pee. Or to actually hold in pee. Not having female bits myself, I don’t think I’ll ever be able to experiment on myself to test if there’s a better cue to use on women. But I do know that this is an introductory cue, and over time you want to build up a little more control than having the musculature completely on or off.
For men, the introductory cue is something I can much more easily empathise with: suck your balls (sorry, no spotters or assistance allowed) up into your stomach. You may be wondering why a man would want to learn to control his pelvic floor. After all, we aren’t usually trying to avoid peeing during exercise. Nor are we trying to make things as tight as they were before we had three kids. Unless you have a very interesting story. Well, there’s two reasons, and they apply regardless of what equipment you pee with.
The first reason is that the transverse abdominis and pelvic floor, along with a few other muscles around the hips and trunk, tend to activate better in unison. The overall tension in the midsection increases, which allows you to make better use of your core and become stronger safely. The second reason is that sharting while your squat or deadlift is common enough among men to be an inside joke in the lifting community. It doesn’t need to be. Learn to use your pelvic floor and it will become an aberration for anything to come out of your rear end other than pure strength in the form of intense glute drive.
Using the core while lifting
Even when you aren’t training your core, you should still be using your core. Without a belt, the transverse abdominis (assisted by the pelvic floor and internal obliques) contract to draw everything in. Your belly draws in from the front, and your junk draws up from below. The same amount of stuff exists within your abdominal cavity, but its now more tightly packed. This increases intra-abdominal pressure, which in turn supports the spine and helps to keep the trunk rigid. With few exceptions, we want the trunk to be very rigid and tight under load, as this increases the force transfer between the hips and the shoulders, and it protects the spine.
If you are lifting without a belt, draw your belly in and your junk up. Get tight. Breathe deep, so that you have additional diaphragmatic pressure pushing down, really compressing your abdominal cavity and boosting intra-abdominal pressure.
If you are lifting with a belt, the emphasis changes. Now, instead of drawing your belly in, your objective is to push your abs out through the front, sides and back to fill up your belt. Your belt should already be fastened tight, so as you push out into it, things are going to get really tight. Again, fill your lungs. Breathe all the way down into your pelvis. Your rectus abdominis and external obliques will activate due to pressure being placed on them and your trunk will become very sturdy. Most people can squat and deadlift more with a belt than without, because it makes for a very tight, dense trunk. Bench press, overhead press and other exercises are a bit more hit or miss, but you won’t be weaker with a belt on.
Every time we practice a unilateral exercise, our obliques have to kick into action. So a great way to train your obliques without having to actually train your obliques is to do one-sided movements: one arm rows; one arm presses; step ups; suitcase deadlifts; and one legged deadlifts are all great options. This works because if it didn’t, being loaded on one side and not the other would result in being pulled out of position in the direction of the weight. The trick, therefore, is to maintain solid form as much as possible, while being conscious of properly bracing your whole core.
Training the core directly
From a functional perspective, we always want to start with activating and controlling the transverse abdominis and pelvic floor before we worry about the outer core muscles. That’s not as exciting when it comes to the mirror, but it deals with the more important jobs that your body needs doing. Beyond using your transverse abdominis and pelvic floor in all your normal exercises, one of my favourite transverse abdominis exercises is the bird dog.
Before I learned the bird dog, I went straight to the plank as a transverse abdominis exercise. When your abs are already strong, this can work. For the average beginner, though, planks are too intense to properly activate and control a muscle they didn’t even know they had. Most beginners will struggle to maintain a good position in the plank, and if they do it will be because their rectus abdominis is doing a lot of anti-extension rather than because their transverse abdominis is holding their guts in. The bird dog, on the other hand, is much easier to control due to decreased torque, and because it features unilateral movement it uses the internal obliques for added support. Win-win.
When it comes to loading up the outer abs, we can load them either dynamically or isometrically. That’s fancy-talk for training them by making them move or training them by preventing movement, respectively. Because of this, crunches, sit ups and planks all work. Crunches dynamically take the rectus abdominis through flexion, while planks use rectus abdominis isometrically to resist extension of the lower back. For a long time, sit ups were popularly written off, because all the movement is in the hips, so people reasoned that sit ups were a hip flexor exercise rather than a rectus abdominis exercise. In reality they train both the hip flexors and rectus. Just like in planks, rectus abdominis is trained isometrically, keeping the spine neutral. Just above the bottom position, the torque is actually very high. Add some weight and you have yourself a surprisingly brutal ab exercise.
The outer obliques enjoy similar benefits. We can train them dynamically through rotation and lateral flexion of the spine, or isometrically through exercises where the goal is to keep the spine rigid against strong forces that threaten to cause lateral flexion and rotation. A word for the wise, though: anti-flexion and anti-rotation exercises always carry over to the big lifts and athletic activities that require high degrees of tension, and they don’t risk wear and tear on intervertebral discs in the spine. The simplest lateral flexion exercise in the world is the side bend, in which you hold a heavy weight by your side, lean into the direction it’s pulling you, and then come back up straight. And the simplest anti-flexion exercise for your obliques is to take the side bend and remove the bend. The exact same muscle will be worked, but in a different way. A slightly more interesting variation is the suitcase walk, in which you keep your torso upright and your shoulders square while walking around with a heavy weight in one hand. Or, if grip’s a limiting factor, you can try waiter walks, where you hold the weight (usually a kettlebell) up at shoulder level.
By now you should know what each of the muscles that make up your abdominals are. You should know how to contract them, and be on your way towards learning to control them. Control is always a work in progress, so keep practicing. You should know how to use your core with or without a belt, and how the obliques in particular benefit from unilateral movements. You should also have an idea of what types of exercises you can use to train your abs directly. Now go lift something heavy.