There are many "givens" in the fitness and physical therapy world, and as someone who is seeking to help others, it's important to continually challenge those norms. I do this with my own philosophies constantly - I'm always looking for different angles, and I often prove myself wrong. That's the beauty of this industry. It's changing as we learn more about science, the body, and the brain.
To that end, I want to apply an analytical lens to norms about the "core." I always challenge my clients that if they aren't getting the results they want - either because they are in pain or because they do not see progress, it might be a good time to re-evaluate your routine and beliefs. `
The "core" is a common term used in the fitness world, but it has various definitions and isn't very specific. In this post, I'll often use the word "trunk," which refers to all the muscles in 360 degrees surrounding your spine.
Hopefully, questioning these norms will guide you towards making decisions about how to view your trunk and how to work/stabilize the muscles of the trunk.
Let’s use the example of sitting on a ball to balance or standing on a foam pad. Although you often bear down in your core muscles and receive slight isometric benefits, the trunk does not have to resist an external force. If your trunk is vertical, the trunk muscles don't have to work against gravity. This might be a good proprioceptive activity for awareness building, but it won't be effective in building strength in the trunk.
To see substantial tissue changes and increase muscle mass, you have to place load through muscle, whether that load is from gravity or external load from a weight/cable/resistance band/etc.
To load the muscles of the trunk (or any muscle for that matter), the force has to be relatively perpendicular to the muscle, like in a crunch or in a spine extension (cobra).
Think about it this way. Where do you feel your abs more: In a standing or in a hollow body position? (See pictures below).
The joint positions are very similar in both positions, but they feel completely different. This is due to the application of force. Your abdominals have to resist gravity in a hollow body, whereas gravity is not working against them when you are standing. The hollow body will, therefore, challenge the abdominal muscles significantly more. (I am not implying you should do a hollow body. This is just for illustration purposes). In standing, the abdominals could benefit from isometric contraction (creating the resistance by thinking about contracting your abdominals). Still, they are not receiving external load and will not be optimally strengthened.
To find out if you're optimally strengthening/working a muscle, ask yourself these things:
If both of these things are true, you are optimally targeting that muscle.
*Isometrics can also work muscles, but they aren't necessarily moving the origin closer to the insertion. Although isometrics can be beneficial, they usually don't produce optimal strength gains compared to moving dynamically through a muscle's entire range of motion.
Check out this video if you want to learn more about this:
Although this could be true, some evidence shows no strong link between core weakness and lower back pain (Augeard) . This review suggests that those who do long-term core stability routines are not less likely to have lower back pain. Now, this doesn't mean that you couldn't benefit from trunk strengthening, but it's suggesting that it might not be your solution.
In addition to the lack of evidence, there is confusion about what trunk/core strength means. Many of my clients assume that it means their abs are "weak." Although this is true in some cases, it can't be assumed that doing more crunches will help your lower back pain. Properly loading the trunk muscles in 360 degrees might be more beneficial than doing sit-ups every day.
Anecdotally, I find that many of my clients with lower back pain have weak back muscles and relatively strong/connected abdominal muscles. Many of my clients with back pain move through the trunk and hip flexion often (bending forward), and might not be balanced in the trunk and hip extension (glute and back strength).
Your lower back pain/tightness is probably a derivative of accumulating stress in a multitude of factors. The most common culprits are:
The first step to improving your back pain is to remove the stress (move more and in appropriate ways for your body structure and tissue tolerance) and slowly load the trunk and extremities in appropriate ways.
If you are truly working your trunk muscles to fatigue and properly loading them (Click this video for my favorite trunk exercises), they require rest just like any other muscle. Gaining strength requires a break-down of tissue, then giving your body time to rebuild that tissue stronger.
I wouldn't recommend doing 100 crunches every day, but I've heard this recommended in the fitness industry. You wouldn't do 100 bicep curls every day and expect your elbow to feel nice and healthy. I've said it before, and I'll say it again - repetitive overuse can cause tissue inflammation and a whole host of issues. The key is to load your tissues with enough repetition to stimulate change, but not so much that your immune system is overwhelmed.
Planks do work your abdominals, but only isometrically. They also work your back muscles isometrically. Planks can be a great option for someone looking to work their trunk, but have back pain with dynamic trunk exercises like crunches, rotation, and spine extension. However, to get optimal results from training the abdominals, move them dynamically. (Here are my favorite dynamic trunk exercises).You can always stay in a smaller range of motion!
As mentioned above, the line of force, or resistance, must be somewhat perpendicular to a muscle to get the best effects from resistance training. Any time you are holding a weight, and your body is vertical (lunges/standing/etc.), your trunk muscles are not placed under significant external load. Your BONES can be loaded (if you have a bar on your back or if you're holding weights), but the trunk muscles need to have the forces applied to them perpendicularly. Even if you're moving your arms or legs, you can still "tighten" your trunk muscles, but they won't be substantially worked.
This is the same concept that I discussed earlier. The trunk is vertical. Therefore, the trunk muscles are only isometrically contracting without any external load. But let's also look at this from another angle.
I wish that killing two birds with one stone in a single exercise was effective, but it comes with a trade-off. Your body is always trying to seek stability as it's number one priority. When instability is sensed, whether trying to balance on a ball and do bicep curls, stand on one leg and do overhead presses, or even doing a compound exercise like a squat, your body will decrease its ability to generate force. So, you are losing the strength benefits and the balancing benefits, where you could get more out of each exercise if you separated them.
You can try for yourself:
It's like trying to hold a conversation while typing an email. If you just committed to one at a time, you would complete both tasks much quicker and with fewer mistakes.
Not only is separating the two more effective, but it is also less risky. Your body will be more stable, which means less can go wrong. You will produce the results you want faster, with less likelihood of injury. This is why we are very specific with strength training in Levo, and why my clients see huge strength gains and much less pain in their bodies.
This is the same issue, just a different example. I want to break this down from yet another angle.
You will often hear that a squat is a catch-all exercise. You will hear that a squat works not only your legs, but also your core.
Maybe a little, but still not my preferred exercises for either the core or the legs.
Depending on your trunk's angle, your back muscles will be loaded (the more perpendicular your trunk is to the floor, the more work your back muscles will feel – i.e., a deadlift). Your abs are not loaded at all besides bracing, which can be done without weight and additional compression on your back, and all the other million things you have to focus on when you squat. Because your body senses it has a lot to do to keep you stable, you will not yield the greatest strength benefits from a squat. I'm not saying squats are bad - but I am saying that there are better ways to work your core and your legs without the high risk of injuring your back.
Bottom line: saving time should never be a reason for doing an exercise. If you want to build strength in your legs, I recommend getting more stable in your spine. Some of my favorites are the leg press machine, heavy clamshells against a wall, and wall sits. With these, your body has less to focus on and can produce more force through the legs. Remember, safety is your body's number one priority. It's always searching for stability before it will produce force.
Check out this video about why training muscles, not movements, is more effective:
1. Give the trunk muscles their own attention. It doesn't have to be fancy, the basics work great. Try my favorite trunk exercises:
2. Don't assume your back pain is because of your weak "core." Take a look at your routine to evaluate what could be stressing your spine (Click here to take this overuse assessment if you are concerned that overuse might be a factor), and remove the stressors if possible. Then work to load the trunk muscles progressively.
Augeard N, Carroll SP. Core stability and low-back pain: a causal fallacy. J Exerc Rehabil. 2019;15(3):493-495. Published 2019 Jun 30. doi:10.12965/jer.1938198.099