If you’re trying to get more abdominal definition, you probably do a variety of ab exercises, including the mother of all ab exercises, crunches. Yet, balanced abdominal training should include more than standard crunches. Crunches primarily target the large, paired muscles in the front of the abs called the rectus abdominis. However, this isn’t the only muscle group that makes up the abdominal region. You also have oblique muscles that run down the sides of your mid-section. A number of exercises target these muscles effectively but whether you should include these exercises in your routine is controversial. Here’s why.
The Anatomy of Your Mid-Section
As mentioned, the most superficial muscles in the front of the pelvis are the two rectus abdominis muscles. These muscles are separated by a layer of connective tissue called the linea alba. On the sides of your pelvis, running diagonally, lie the exterior oblique muscles. These muscles originate from the lower ribs and are important for rotating and abducting the trunk.
Beneath the external obliques lie the internal obliques. These deeper muscles lie just above the deepest muscle in the abdominal walls, the transverse abdominal muscles. The internal obliques contract to help expel air out of your lungs when you breathe. They also, along with the exterior oblique muscles, are involved in rotating the trunk.
Is Oblique Training Beneficial or Not?
How much time should you devote to training these muscles and why it is controversial? Since the oblique muscles run down the sides of your mid-section, hypertrophying these muscles could actually widen your waistline, especially if you do oblique exercises using resistance. An example of an exercise that could potentially widen your waistline are side bends holding dumbbells. You may have heard that this exercise helps battle “love handles,” extra fat accumulation around the waist. This is a myth that many people still believe. Since love handles are made up of fat, the only way to really vanquish them is to lose body fat – and that means losing fat everywhere since you can’t spot reduce. Doing endless side bends, if anything, will develop the muscle underneath and make love handles look more prominent. Other exercises that can hypertrophy the oblique muscles and enlarge the waistline are weighted oblique crunches and weighted cable crunches.
Fortunately, you probably won’t get enough oblique development to increase your waist size unless you use a substantial amount of resistance. Doing oblique-focused exercises with light weights won’t lead to significant muscle development. The advantage of doing some exercises that work the obliques is that you get a more balanced core workout. One important muscle that you train with oblique-focused exercises is the quadratus lumborum a muscle deep in the spine. When this muscle is weak, it places extra stress on the lower back and makes you more susceptible to back pain and injury.
So, how can you work this deeper muscle that supports the health of your back without doing oblique exercises that can widen your waist? One way to work the quadratus lumborum without hypertrophying the external obliques is to do side planks. We already know how beneficial planks and their variations are for core stability. Being an isometric exercise, you don’t need weights. Doing side planks won’t hypertrophy the muscles but will work the other muscles, including the quadratus lumborum, that help protect your back.
Don’t forget that some of standard ab exercises that most of us routinely do, such as bicycle crunches and “windshield wipers” also work the obliques. Since you typically don’t use weight when you do these exercises, it’s unlikely you’ll get significant oblique development and get a boxy looking waist as a result. The key to getting a balanced core workout without enlarging your waist is not to do side bends and oblique crunches while holding a heavy weight
A More Balanced Approach to Training Your Abs
If you’re concerned about building your obliques, do more compound exercises and fewer isolation exercises for your abs. Compound exercises, including squats and deadlifts, activate your ab muscles as well. Plus, they work the muscles in your back too for balance. If you’re concerned about a muffin top, do exercises that work multiple muscle groups at the same time, like deadlifts and squats. These exercises burn more calories and create more of a metabolic effect for enhanced fat burning. These are the exercises that you should focus the majority of your training sessions on because they work so many muscle groups and offer so much return for the time you spend. They also help to injure proof your body by creating a strong core.
Too many people still believe that abdominal isolation exercises you do on a mat, like crunches, sit-ups, bicycles, and leg lifts are the key to a six-pack. If you have a layer of body fat over your abs, compound exercises that work multiple muscle groups, including your abs, should be a priority.
Don’t completely eliminate ab isolation exercises. Deadlifts and squats activate the abdominal muscles but relatively weakly. The biggest advantages is they work your abs AND your back for a more balanced workout. Plus, they burn more calories. That’s a positive if you’re carrying excess body fat. Planks actually activate the rectus abdominis and obliques more than squats and deadlifts, making them effective for strength development but less likely to overdevelop the waist. Again, with planks, you strengthen the stabilizer muscles in your hips and back as well for greater protection against injury and they do it without flexing your spine. There’s some thought that dynamic flexion of the spine, as with crunches, can prematurely age the spine and increase the risk of disc disease. Including more isometric exercises, like planks, and fewer exercises that flex the spine may be gentler to the lower back and spine.
The Bottom Line
Don’t overdo abdominal isolation exercises, especially if you still have a lot of body fat to lose. Focus more on compound exercises and planks to get a balanced core workout. Weighted side bends? Avoid them.
ACE ProSource: Abs! Abs! Abs!
Medicine & Science in Sports & Exercise: May 2011 – Volume 43 – Issue 5 – p 396. doi: 10.1249/01.MSS.0000401092.05865.1c.
Strength & Conditioning Journal: August 2011 – Volume 33 – Issue 4 – pp 8-18.doi: 10.1519/SSC.0b013e3182259d05.