Core Stability and Strength

Core activation, or core work, is one of the most important aspects of any healthy workout routine!

Our body is connected throughout, in ways most of us never consider. Imagine your body is a network of trains. We have many train stations and a few main depots, but the trains run through our entire body sending messages and packages that are necessary for our body to function properly. They may start in different places or end in different places, but the one thing they all have in common is that they all pass through our torso somewhere along their lines of travel.

What is Your Core?

The definition of “core” is “the central, innermost, or most essential part of anything.”i Our core is our center. It is where our center of gravity is; where our heart, lungs, and most other crucial organs are; and where our main nervous system runs. Our core muscles control our spine, our hips and pelvis, and our rib cage. Overall, it is the heaviest part of our body, aside from our head (by size). If we have control over our core, we have more control over our whole body, including our arms and legs. So keeping our core healthy and functional is essential to overall health and body function.

When most people think of core, they think of ab muscles. They aren’t wrong but there is more to your core than just your abs. Your core consists of all the muscles and fascia that support and move your spine, hips, pelvis, and ribs. Pilates lists the transverse abdominis, pelvic floor muscles, multifidi, and diaphragm muscles as the main core points.ii We at Urban Fitness would include a number of other torso muscles, including the rectus abdominis, the obliques, and the lats (latissimus dorsi), as essential core muscles meant to help control and support the core.

Why Core Work, and a Functioning Core, Is So Important:

These various core muscles and fascia connections work to move the body and support the spinal, pelvic, and hip joints when lifting, bending, sitting, twisting, walking, running, and jumping. We all do at least some of these things, if not most of them, on a daily basis. Keeping our core strong and functioning properly is important for many things, including, but not limited to, ease of daily life, injury prevention, and injury recovery. When these muscles do not function properly, it can lead to a whole host of problems. It can cause daily tasks to be more difficult or painful. Even something as simple as bending down to pick up something, lifting something off a shelf, or vacuuming the floors can become a real problem when our core isn’t strong enough. A lack of support from core muscles can make walking and moving become clunky or painful due to added stress or pressure on the legs and hips. Even arm movement can be restricted when the core doesn’t function properly.

Injury Prevention:

Many injuries are caused by imbalanced or weak core muscles. One of the most important things to remember about our body in general is that our muscles are designed to work together. When one set of muscles isn’t working properly, another set of muscles has to work even harder to compensate for the muscles that are not. This causes body imbalance and adds strain and stress to the body. Our core is such a complex and large unit that core functionality really requires the equal cooperation of all of our core muscles. Just think of all the different ways your torso can move in a typical day. Thanks to sitting based jobs, we sometimes move our core more often than we move our legs. We need our core to function smoothly and easily to help prevent pain or injury.

When our core functions optimally, we create space in the joints of our core. This includes our hip bones and, most especially, our vertebra. Our spine is just one long column of joints. Our abdominals and multifidi help support our spine. When these muscles are functioning properly, they help create space between the vertebrae, also known as decompression of the spine. This space helps prevent wear and tear on the cartilage in our joints and the bones themselves. The space between our vertebrae acts like a cushion or a shock-absorber when pressure is placed on our spine while walking, running, or jumping. This space also supports our spine against the constant pull of gravity and is beneficial for movement. Asking insufficiently spaced vertebra to twist or bend, even just to grab something, is like asking a group of people in a crowded elevator to do the cha cha; it just doesn’t work.

The space created in your spine is also helpful for preventing injury to your hips, knees, and ankles. When your spine is supported, and your core muscles are functioning correctly, it takes the weight of your torso out of your hip joints. That, in turn, places less weight on your knees and ankles, creating more space in those joints. Crushed together joints have a high risk of all sorts of injuries and are a common cause of chronic or recurring pain. Once the spine shortens due to instability in the core, it is difficult to keep everything below it from getting crushed or stuck because of the added weight on the lower joints.

The rib cage also needs support from the core muscles. The lats and diaphragm help support our ribs and our obliques help connect and control our spine, pelvis, and rib movement. These muscles also help support our diaphragm which controls our breathing. When these muscles function correctly, they help keep the weight of the rib cage, as well as the spine, off the lower joints. Just as the weight of a crushed spine can hurt the lower joints, so too can the weight of a collapsed rib cage. The collapse of the rib cage due to weak core muscles can also make breathing more difficult.

 Core muscles also help support and control the hips themselves. In fact, our low ab muscles are responsible for not only creating support in our low back but also for holding and controlling our hip bones. Our pelvic floor muscles help support and stabilize our sit bones and pubic bones which also helps support and stabilize our SIs (sacroiliac joints). In addition, our core, specifically our pelvic floor muscles, helps keep our insides, or viscera, up inside our body, against gravity pulling on them, and helps to control our bathroom activities. The pelvic floor muscles also help support our hips when we sit and stand. When these much smaller muscles fail to work, it can lead to tight hip flexors and IT bands, SI problems, sciatic nerve issues, and low back problems. Also, a lack of hip control or stability can make everyday movements much more difficult or painful. Therefore, a strong core can also help prevent injury in these areas as well.

Injury recovery:

Not only is core work important for injury prevention, it is also extremely important for injury recovery. Most injuries, from basic injuries to severe ones, are treated with core work as part of the recovery focus. This is partially why Pilates work is so popular with physical therapists.

One of the most common problems treated with core work is low back pain. We have treated many clients with low back pain over the years. It is an extremely common occurrence in our modern era, yet, when we incorporate core work into their routine, particularly ab work and back muscle release exercises, their pain gets better or goes away completely. Hip injuries, sciatic problems, and SI problems are often treated, at least in part, with core work as well. In fact, when the low abs don’t engage properly, outer hip muscles and hip flexor muscles tend to work more to pick up the slack. These tight hip muscles can cause more low back or hip pain because they are then constantly pulling on hip bones and tightening low back muscles which have no support from the low ab muscles.

Neck and shoulder pain is also often treated with core work. Neck muscles, particularly traps, often take over for weaker upper ab and lat muscles. Your traps support your shoulder blades from the top while your lats help provide support from the bottom. When the lats don’t do their job, the traps work more. Once the traps are tight and overworked, which is a common problem in our technology age, traps also try and take over the job of moving the upper spine. However, it is the job of the upper back muscles, including lats, and the upper abs muscles to control and move the upper spine. So tight necks and shoulders are often treated by strengthening the lats and upper abs.

Perhaps the best example of how important the core is to the whole body, however, is the problem of a twisted alignment in the core. This is when your hips and/or rib cage, and thereby your spine, are twisted either to the left or the right (or one of each). While being twisted is not technically an injury in and of itself, like most misalignments, it can often cause or contribute to injuries throughout the body and frequently causes a great deal of pain in those who are twisted. The state of being twisted is improved through core work, among other exercises, because it is the core muscles that stabilize the torso and help keep it aligned. When twisted, the client usually has built strength in one side of certain muscles but lacks strength on the other side of those same muscles. To undo the twist, the weak muscles must be strengthened while the stronger and overworked muscles must be stretched or allowed to release some.

What is Core Work:

Core work, simply put, is any exercise that works or stretches the muscles of your core. Any decent strength training routine includes some amount of core work. Pilates involves a majority of core work and is often what people turn to when looking for a more in-depth core routine.

Stretching your core muscles is just as important as working them. A lot of core workout exercises include an element of stretch built into the movement. However, stretching our core muscles is still important. Muscles cannot function correctly if they are too tight, any more than if they are too weak. In addition to not working as well, overly tight muscles or overworked muscles can prevent other, weaker muscles from being able to engage at all. Examples of core stretches are things like back stretches, lateral bends, and back bends. We want our core muscles to be strong but also flexible to make movement and other muscle engagement easier.

Some strength-training core exercises focus on one core part more than another, such as an upper ab exercise. While all of your abs should be working during an upper ab exercise, like crunches, the upper abs are being targeted and are working more than the others. Meanwhile, some core exercises work your entire core at once. Planks are an excellent example of a core exercise that can work your entire core, when they are done correctly. The most difficult part of core work is doing it correctly or effectively.

What is Effective Core Work:

If not properly trained on how to engage their core effectively, nine times out of ten, people don’t do core work correctly. This leads to either not getting the full benefit of the exercise or continuing to use the wrong muscles, thereby creating a greater risk of injury. Remember, one of the most important and complicated things about core activation is that there are a lot of different core muscles. In order to have a fully functioning core, all the core muscles work together to support your torso and the movement of your torso. It is rather like a large factory or office. There are a lot of different parts and departments, but in order to get the product (movement) out efficiently and effectively and with no one department or worker overworked, all the different workers (muscles in this case) must do their jobs to the best of their ability and not take on the work of the other workers as well.

A truly effective core workout helps involve and strengthen the smaller or weaker core muscles as well as the bigger and stronger ones. Small muscles often require small and precise movements to find and strengthen them. This kind of detailed work can require a lot of thinking, especially to correct any bad habits you may already have. It can take a lot of patience, practice, and body awareness as well.

General Ab Engagement Effective v. Non-Effective:

For any ab exercise, there are two ways to engage your abs. The first is the most common: it pushes the abs away from the spine and works only the center strip of the abs. Most people work their abs this way because it is “easier” to find and feels like their abs are working harder. However, the correct way to work the abs is to press them into the spine and then spread them wide to the sides of the body. This works the center and sides of the abs and it works the smaller abs muscles that are underneath the bigger ab muscles, thereby spreading the work load out between multiple muscles instead of one muscles trying to do it all. Finally, it builds the abs flatter, instead of rounder, giving a flatter look to the stomach area overall.

Examples of Effective v. Ineffective Core Workouts:

There are many ways to make your core workouts effective. Here are two examples of common core exercises. One is done incorrectly and one done correctly. These demonstrate how changing the way you do and think about an exercise can change the entire feel and benefit of the same exercise.

Bird Dog or Opposite Arm and Leg Reach:

This exercise is commonly used in gyms, fitness videos and classes, and by physical therapists. However, it can easily be done wrong:

In the above pictures, this person is over extending, or arching, her back. That forces her abs to release and her back muscles to grip or over engage. In any core exercise, if you feel your low back or hip muscles straining, your low and mid abs are not working. She has twisted her hip open to get her leg up, thereby, creating instability in her hips and using her outer hip muscles instead of her pelvic floor.

The actual purpose of this exercise is to strengthen low and mid core muscles and improve lumbopelvic stability. To get these benefits, this time, she has kept the movement smaller, thereby keeping her in better alignment. Her straighter spine allows her to press her abs into her spine and spread them wide to the sides of her body. This method of ab engagement allows her to access her smaller, deeper ab muscles to provide better spine and back support. The length of her spine, ears reaching away from hips, also allows her vertebra to be long and stretched apart instead of crushed together, creating even strength in her multifidi. She has kept her range of motion where she can control it and isolated her leg from her hip bone. Often with effective core workouts, less is more. She has kept her leg behind her and her pelvis stable which allows her to release the other picture example’s over-worked hip muscles and, instead, puts her in a position where she can engage her pelvic floor muscles. Her arm is also staying lower, which has kept her from straining in her neck, chest, shoulders, and upper back which allows her ribs not to flare. That means her upper abs can connect to her mid abs to help support her low abs.


This is another commonly used, but commonly misunderstood, exercise. When done correctly, this exercise works the entire core, but it is an advanced and difficult exercise, that it is very easy to do incorrectly.

Just like in the last example, in these pictures, this person is over extending, or arching, her back. That forces her abs to release and her back muscles to grip or over engage. Her hips are too high, ie not in line with her heels and head, causing strain in the hip muscles as well as the low back. Her shoulders are up towards her ears and collapsed into her back towards her spine. This causes her neck muscles and upper back to do too much work. Her rips are popped out to the floor, forcing her upper abs to release, and her lats to collapse.

In this example, she has improved her alignment. Alignment and core work are very interwoven. Better alignment makes for better core work. Better core work makes for better alignment. Her straighter spine allows her to press her abs into her spine and spread them wide to the sides of her body. This way of ab engagement allows her to access her smaller, deeper ab muscles to provide better spine and back support. It also, in an exercise of this level, allows her to start engaging her obliques to help keep her sides long and strong. The length of her spine, ears reaching away from hips, also allows her vertebrae to be long and stretched apart instead of jammed together, creating even strength in her multifidi and even strength in her other back muscles. Her hips are not too low (or too high) and her hips are level (not dipped to one side or the other). That allows her pelvic floor and low ab muscles to do their job in helping support the hips, pelvis, and low back. She has separated her sternum from her collar bone and sent her sternum, mentally, down through her tail bone. That has allowed her to lengthen her low back instead of scrunching it. Her front ribs are in and back towards her spine, without her upper back rounding. That allows her upper, mid and low abs to work together to help push her back up against gravity to maintain the plank position. Finally, her shoulder blades are wide, not collapsed, allowing her lats to help support her rib cage and shoulders. Can you see how activating all of these various muscles can make planks easier and more effective in the long run?

What We at Urban Fitness Do:

Core is an extremely important part of our client workouts. We help our clients find core exercises that are right for them that day or week so they can have effective core workouts that work the weak muscles as well as the strong. We use cues and imagery and, when possible, hands on corrections to help them find the difficult-to-find small muscles. We also use corrections to help each client find their optimal form, just like in the examples above, so they can get the most out of any exercise, new or familiar. Unlike the pictures above, however, we use our students’ feedback about what they feel and what makes sense to them, as well as our own visual cues, to discover which exercises and corrections work best for each individual client. We even include core tips and corrections in non-core-based exercises, since using your core correctly improves the benefit gained in exercises for arms, legs, glutes, shoulders and even stretches. We know our bodies are completely interconnected and we strive to make sure that the place where all lines pass, our core, is as strong as it can be for each client to help prevent injury, heal from injury, or just move and feel better now and as we age.

Looking to add or improve a core workout routine? Schedule your free 90 minute consultation.



This blog was contributed by our Pilates guru, Kaethe Birkner. Kaethe is a certified Pilates instructor through Balanced Body and dances ballet professionally at Continental Ballet Company. She has been teaching Pilates since 2012 and has been taking Pilates since 2004.




Addie Kelzer is a certified personal trainer and nutrition consultant. She believes that by making fitness and good food practical, her clients will hold the power to positively change their health and the health of those closest to them.

, accessed 4/11/21

iiBalanced Body Training Manuel, 2009-2010