How many muscles do you think are in your core?
One muscle? (Your six pack abs of course!?) Maybe 2 or 3 or 4? The correct answer is 35! That’s right, there are 35 different muscle groups spread across your trunk and hips. You have lateral trunk muscles, hip muscles, abdominal muscles and back extensor muscles, each of which is crucial for your day to day living. This article is going to tell you why a strong core is important and break down the essential muscle groups of your core, explore their functions and give you actionable advice for improving your own core through training.
Let’s break down the anatomy of the core
As fun as it might be to sit here and go over each of the 35 muscles in detail, let’s save ourselves a bit of time and focus on 8 major muscles and their associated movements.
Rectus Abdominus: Commonly known as your ‘six pack’ abs, this muscle group is responsible for hip flexion. For movements where you crunch or contract your trunk, the rectus abdominus will be your primary muscle group.
Tranversus Abdominus: This muscle group can be described as your ‘deep stabilisers.’ The transverse abdominus or TVA helps to provide stability to the ribs, hips and back. If you have to perform any heavy lifting either for training or for work, a well-developed TVA can reduce spinal pressure by as much as 40%. (Hodges 1997)
Internal and External Obliques: Located on the side of your trunk, these can be thought of as your ‘rotational muscles.’ Any time your trunk must rotate or resist rotational forces your obliques will be doing most of the work. In the world of sports, it’s common to see overworked and even strained obliques in baseball and tennis players.
Pelvic Floor: This muscle supports the contents of the pelvis, including the bladder, intestines and uterus in women. Put simply, without a working pelvic floor thing start to get messy with issues like urinary incontinence being just the start! A strong pelvic floor also assists women with childbirth and men with maintaining an erection, so it might be worth doing those kegel exercises after all.
Erector Spinae: This group of tendons and muscles is all about keeping you upright and serve to extend your back. They are located either side of your spine and are especially prominent in strength sport athletes such as this professional weightlifter below.
Multifidus: This collection of muscles is best described as your ‘spinal stabilisers.’ These muscles run just superficially along the length of your spine, adding stability and stiffness which improves the function of each vertebrae and reduces disc degeneration. Interesting tip for you, recent research has showed that kegel (pelvic floor) exercises also help to strengthen the lumbar multifidus muscles, potentially helping with lower back problems.
Quadratus Lumborum: Located at the bottom right and bottom left of your back, your quadratus lumborum muscle pair is the deepest of all your core muscles. These muscles have two functions depending on their use. If just one is used, it will contribute to lateral flexion, i.e. side bending. If both are used, they will contribute to spinal extension, assisting the spinal erectors. Importantly, these muscles can become tight through excessive contraction due to sitting for too long, which can contribute to lower back pain.
Why the combination of core muscles is important
We know, then, that each core muscle group is important independently, but it’s your core muscles’ function as a unit that makes them the most important. Together, your core muscles constantly work and interact with each other to maintain your posture. If just one muscle becomes too tight or too weak, you will start to see breakdowns in your posture such as kyphosis and lordosis (pictured below) which ultimately lead to back pain, neck pain, hip pain, shoulder pain and other issues.
A quick recap of reasons why a strong core is important
So, your core helps to maintain your posture, stabilise your spine, support your ribcage and hips, prevent back, neck, hip and shoulder pain, help you give birth, improve sexual performance, plus is responsible for your ability to flex, extend, rotate and side-bend. All in all, then, your core is pretty darn important!
How to train your core
The following exercises will address each of the areas of the core mentioned earlier in the article. Moreover, since the current literature consensus is that a mixture of static and dynamic (movement based) core exercises is best for adaptation, the list will contain a mixture of both types of exercise.
Flexion based exercises: These are great for training the rectus abdominus. Simple exercises such as sit ups, crunches and hanging leg raises are all perfect for this. A word of caution though, try not to overdo the amount of these. Most of us spend a lot of time sat down, which leaves us with pretty tight hips, and all these flexion type movements tend to tighten your hips up. Two or three sets per week is a good number to start with.
Anti-extension based exercises: This category of exercises is all about preventing hip extension by holding a braced midsection. These are ideal for developing the transverse abdominus (TVA) muscles. Good exercises include planks, aleknas and deadbugs as shown below.
(Anti) lateral flexion based exercises: This category is all about side-bending (or resisting a side bend in the case of anti-lateral flexion movements) If you properly read through all the core muscle information above, you’ll know that this means you’re developing your quadratus lumborum muscle group. A great combination of exercises you can perform are a side plank for anti-lateral flexion, and a weighted side bend as pictured below for lateral flexion.
(Anti) rotation-based exercises: This category of core exercises is important for developing your internal and external obliques, also known as your rotational core muscles. A good static anti-rotation exercise you can perform is a paloff hold, whilst a good rotational exercise you can perform is a cable rotation.
Extension based exercises: If you’re looking to develop your erector spinae muscles then you’ll want to include some back extension type exercises in your training. If you’re a beginner, try starting with lying supermans. If you’re more advanced, try moving onto back extensions.
Kegel based exercises: Ironically, although these exercises are the least sexy to perform, they’re also the most likely to improve your sexual performance. If you were reading properly above, you’ll know that these exercises help to strengthen your pelvic floor muscles as well as your multifidus, a major spinal stabiliser. Over time, they can help to reduce lower back pain, so they’re an important part of any core training programme. Mayo Clinic has produced handy guides for both men and women.
How much and how often should you perform these important core excersises?
Most combinations and frequencies will work for these exercises, what’s most important is making sure that you perform them all on a regular basis to challenge the muscles. You could perform two sets from each category, so 12 sets in total, which including rest times should take no more than 25 minutes. Doing this once or twice per week would be a great start towards improving your core. Alternatively, if you’re already active in the gym, playing sports or taking part in a physical hobby, you could divide your exercises across the days, performing two sets of two different categories after each activity; for example…
- After Activity 1: flexion and anti-extension
- After Activity 2: anti-rotation and anti-lateral flexion
- After Activity 3: Extension and Kegels
Remember, what’s most important is that you consistently perform the exercises every week, trying to make little bits of progress over time by increasing repetitions, holding for longer, adding more weight or adding extra sets. Keep working away and you’ll reap the benefits.
You now know that your core consists of 35 different muscles, and you know the names of 8 of the most important ones, and that these muscles both create and resist flexion, extension, rotation and side bending of the torso. You also know that these muscles work together to stabilise your body, maintain your posture and prevent various types of pain. Finally, you know a selection of reliable exercises that you can perform every week to improve your core strength. That’s ten minutes reading time well spent!
If you enjoyed reading this, make sure you check out my post “How to strengthen the core muscles, using only your bodyweight” for more excersising tips.
Hodges, P., Richardson, C. (1997). ‘Contraction of the Abdominal Muscles Associated with Movement of the Lower Limb’. Physical Therapy. 77 (2): 132–44.
McGill, S. (2010) ‘Core Training: Evidence Translating to Better Performance and Injury Prevention.’ Strength and Conditioning Journal. Volume 32 – Issue 3 – p 33-46
Starkey, C. (2012). ‘Additional Spine and Torso Therapeutic Exercises’. Athletic Training and Sports Medicine: An Integrated Approach. Jones & Bartlett Publishers – American Academy of Orthopedic Surgeons. p. 583