Sedentary work and reduced activation of core musculature – how modern lifestyles affect musculoskeletal health.
· Oppdatert
Most of us spend large parts of the day sitting – at a desk, in the car, on the sofa. The changes brought about by a modern way of life have affected both activity levels and movement patterns faster than our bodies have been able to adapt, and we see the consequences clearly in the form of increasing musculoskeletal complaints. The core musculature in particular, which should provide dynamic stability to the spine and pelvis and more throughout everything we do, appears to be losing ground when it is no longer challenged in the same way as before.
Most of us spend large parts of the day sitting – at a desk, in the car, on the sofa. The changes brought about by a modern way of life have affected both activity levels and movement patterns faster than our bodies have been able to adapt, and we see the consequences clearly in the form of increasing musculoskeletal complaints. The core musculature in particular, which should provide dynamic stability to the spine and pelvis throughout everything we do, appears to be losing ground when it is no longer challenged in the same way as before.
As professionals and researchers, we know that reduced activation of core musculature makes us more susceptible to musculoskeletal complaints. The EU and health authorities still haven´t recognized the connection between increasing musculoskeletal issues and sickleave, and reduced activation of core musculature. The question we need to ask ourselves is: what can I do to maintain a reasonable level of activation of the core musculature, and which exercises work best to reverse the decline of our musculoskeletal health?
Sedentary work as a health risk – what does the literature show?
It is well documented that prolonged sedentary work is associated with an increased risk of both musculoskeletal complaints and other health problems. When the body maintains a prolonged static position, one consequence among others is a reduced activation of the deep stabilizing muscles in the trunk. These muscles depend upon variation and loading to retain both strength and the neuromuscular control that makes them effective in everyday life.
One specific example of the connection between inactivity and experienced musculoskeletal complaints can be found in a randomized controlled trial of pelvic floor training in sedentary women with lower back pain. The study showed that targeted training of the pelvic floor musculature improved lower back function and muscle performance in women who initially had a sedentary lifestyle and lower back pain (The effectiveness of pelvic floor muscle training on lumbar function and muscle performance in sedentary women with lower back pain).
This illustrates a recurring finding in the literature: a sedentary lifestyle can lead to reduced activity in core musculature generally or in individual muscles – and training specifically targeting these muscles produces measurable improvements in function and the experience of pain. https://pubmed.ncbi.nlm.nih.gov/40108595/
Earlier models placed great emphasis on the deep local muscles, such as the transversus abdominis, multifidus, pelvic floor and diaphragm. These were often described as the key to back stability, and training focused heavily on isolated “motor control” exercises and static exercises such as the plank.
Researchers such as Paul Hodges and Peter O'Sullivan emphasize that stability of the back is not about rigidity or constant muscle tension. Furthermore the term “stability” is not ideal in terms of how it may create an impression that the back may become unstable, thereby creating a kind of fear in some people. Both fear and isolated focus on static activation (contraction of pelvic floor) can cause some people to move in a more rigid and less natural way, and this in turn can exacerbate back pain.
Functionality is about the body's ability to dynamically adjust stability, mobility and force production to the task being performed. The modern understanding does not challenge the importance of the deep local muscles mentioned, but shows that they are only one part of a much larger system.
Whether we should focus more on isolated activation of individual muscles, or attempt a more holistic approach, is a question that creates debate. And it is a field of rapid development. Sometimes there may be considerations suggesting that static and isolated activation may be beneficial, and in other cases we should opt for a different approach. Recent development clearly points towards a more holistic approach to core musculature, with dynamic exercises that often train the whole body simultaneously.
This picture – that inactivity can lead to reduced activation of the core musculature, and that targeted training can reverse this – is the starting point for the CoreCapacity paradigme and exercise selection. There are many questions that need answering. -Which exercises activate which muscles? And how do the level of difficulty and loading of the exercises influence the outcome? This is precisely what our own research has begun to examine more closely.
Our research: do the exercises actually activate the right muscles?
In our latest study published in Frontiers in Sports and Active Living, we investigated how the complexity of body-weight exercises for the core affects muscle activation and perceived exertion (Andersen, Rise, Sandvikmoen, Solstad, Stien, Bjørnsen, Scott, Prieske and Saeterbakken, 2026, Frontiers in Sports and Active Living).
The study included 28 recreational exercisers – 15 women and 13 men, with an average age of 32 – who performed seven body-weight exercises from our core concept, each at three to four different complexity levels. Complexity was adjusted by changing the base of support (more or less unstable), lengthening the lever arm (easier or harder), or moving from bilateral to unilateral execution.
Muscle activation was measured using electromyography (EMG) in three central muscles: rectus abdominis (the straight abdominal muscle), the external oblique abdominal muscle and the back extensors. The results showed that greater complexity produced significantly higher muscle activation – and this effect was clearest in the muscle most specifically targeted by the exercise. At the same time, perceived exertion increased with the complexity level, suggesting that participants themselves noticed the increased load.
This is an important finding for two reasons. First, it indicates that core exercises can be graded systematically – by adjusting the base of support, lever arm, and whether performed unilaterally or bilaterally – and thereby controlling how much a specific muscle is loaded and activated.
Secondly, and perhaps most importantly, the study shows that different core muscles respond differently to the same exercise. The “core” is not activated as a unit; each muscle has its own activation-pattern depending on the design of the exercise.
During only a couple of decades, we have moved away from static and isolated activation of some core muscles, towards a more holistic and dynamic activation of the core as a unit. Our new findings indicate that we may be able to activate some core muscles more specifically than others through our approach.
“Not necessarily a holistic group, but individual muscles” – a clear position
In the publication, we express this finding as a clear position, quoted directly from the article: "This finding implies that the trunk muscles should not be regarded as a holistic group, but rather as individual muscles. Furthermore, this should be an important consideration when designing training programs; that is to say, exercises should be selected based on the particular muscles one would like to stimulate."
This quotation summarizes something that has been a pendulum movement in the field over several decades. In the 1990s and early 2000s, core training was dominated by a doctrine of local, static and isolated activation of individual muscles – often focusing on deep stabilizing muscles. Typical maneuvers involved drawing the navel in and up, and squeezing the pelvic floor – as if stopping the flow of urine. Gradually, the field moved towards a more holistic understanding, in which the core was viewed as an integrated system to be trained functionally and collectively, often through compound movements.
Our study suggests that the pendulum may be swinging back somewhat – not to the old, strictly isolated doctrine, but towards a more nuanced and specific approach. The findings show that when the aim is to stimulate a particular muscle, for example the rectus abdominis versus the back extensors, the exercise should actually be selected and graded with that muscle in mind. A holistic way of thinking remains relevant for many training goals. For many recreational exercisers, it probably fully acceptable to think that an exercise or two tapping into the core region once or twice a week, is good enough.
But if the goal is specific strength development or rehabilitation of a particular area or muscle, thinking of the “core” as one unit may not be sufficient. This is, as we see it, a concrete contribution to new knowledge about how core training should be planned – with practical implications for both recreational exercisers and professionals in exercise and physiotherapy.
From findings to function – practical implications?
This knowledge builds on our recent publications. In a pilot study in Frontiers in Physiology, we investigated the effect of heavy and dynamic strength training for the core on upper-body strength and power performance in national-level junior athletes (Saeterbakken, Sandvikmoen, Iversen, Bjørnsen, Stien, Andersen, Scott and Prieske, 2025, Frontiers in Physiology).
Together with the new EMG study, this presents core training as something more than general "abdominal training" – it is a complex group of muscles that should be trained systematically for beneficial activation of the core, with a conscious approach to which muscle one actually wants to challenge, and with the ability to control loading through the complexity of the exercise.
For those who spend a main part of the day sitting, whether at work or in the car, this is relevant knowledge. Sedentary lifestyle affects activation of the core musculature negatively - no doubt. However, we have less knowledge about how it affects specific muscles differently – depending on static and repetitive loading. We have recently provided findings which suggest that in order to increase the activation level of core musculature, complexity can be gradually increased to ensure continued development.
Conclusion
The literature is clear that sedentary work and reduced general activity have negative consequences for musculoskeletal health, and that specific interventions – such as targeted pelvic floor training in sedentary women with lower back pain – can produce measurable improvements. Our own research takes this a step further and shows concretely how different body-weight exercises for the core activate different muscles differently, and that this activation can be controlled through exercise complexity.
An important message from our latest publication: core musculature should perhaps no longer be treated as one uniform group, but when needed be treated more as individual muscles, with tailored exercises – depending on what one wants to achieve. This is particularly important information for athletes, and should be incorporated and adapted in individual training programs with performance in mind. Nevertheless, the most important thing for an ordinary office worker will be THAT the core musculature is activated, and that a little input is far better than anything at all.
It is worth noting that activation of the core musculature in our study occurs spontaneously, measured through EMG activity.
References:
https://www.youtube.com/watch?v=hplw6Lg95SY&t=218s
https://www.youtube.com/watch?v=fxLdo06ZPd8
https://www.youtube.com/watch?v=YezBG_NdLgs
About CoreCapacity AS:
We communicate information to people about how the latest core training works and affects THEIR OWN HEALTH, in a way that MAKES SENSE, so that they can make GOOD & INFORMED CHOICES about what they want to do to achieve and maintain a GOOD PERCEIVED HEALTH and establish good and LASTING TRAINING ROUTINES for CORE MUSCULATURE.
CoreCapacity provides exercises that start at an accessible level and are SIMPLE AND SAFE to perform, set within a PROGRESSION SYSTEM; exercises that are also ADVANCED to ACTIVATE the core musculature AUTOMATICALLY, with increasing loading and difficulty, contributing to REASONABLE FUNCTION & HEALTH.
We disclose that AI has been used in compiling parts of this text.