A recent conversation with a friend about why we grunt and groan when standing up, sitting down, or bending over, and when we actually started doing this, prompted me to look for supporting literature on the topic. There was not a lot of information available, but I have included a few links below that seem plausible, though I cannot guarantee their reliability or accuracy. Below, I have highlighted what I believe are the main themes related to this phenomenon (from this literature), each explaining the grunting from a different perspective.

Core muscle weakness
As people age, their core muscles, especially the abdominal muscles, naturally weaken. These core muscles are essential for stabilising the body and facilitating everyday movements such as standing up, sitting down, and bending over. Strong core muscles help maintain balance and support the spine during these actions. However, as we grow older, these muscles often become less effective due to a combination of reduced physical activity, muscle atrophy, and changes in muscle composition. When core muscles are weak, performing basic movements requires more effort. This increased effort can manifest as grunting or moaning because the individual needs to exert additional force to complete the movement. This phenomenon is a natural part of aging, and the noises are simply a byproduct of the body’s struggle to compensate for the decreased muscle strength.

Breath control and grunting
Breath control plays a significant role in the production of grunting sounds during physical exertion. When performing a strenuous task, such as standing up from a seated position, older adults may instinctively hold their breath to maximise their muscle strength. Holding the breath creates internal pressure, which can help stabilise the core and provide a temporary boost in strength. This is referred to as the Valsalva manoeuvre. Once the task is completed and the effort subsides, releasing the held breath often results in a forceful exhalation. This expulsion of air can produce a grunt or groan. This breathing pattern is common during high-exertion activities, but it can also occur during simpler movements when the body is under strain. The sound is essentially a natural consequence of the way we manage breath during physical effort.

Pain and stiffness
Pain and stiffness are common issues associated with aging and can contribute to the sounds older adults make when moving. As people age, muscles and joints often become stiffer and more prone to discomfort. For instance, prolonged sitting can lead to stiffness in the hips and lower back. When transitioning quickly from a seated to a standing position, these tight muscles may react with pain or discomfort, causing a reflexive groan. The sounds are not always a direct result of exertion but rather a response to the physical sensations of stiffness or discomfort. This aspect highlights how the noises are sometimes more about the body’s reaction to sudden movements than the actual effort involved in the task.

Habit and signalling
Grunting or moaning can also be a learned behaviour or a form of communication. For some individuals, these sounds might serve as a way to signal to others that they are experiencing difficulty or discomfort. Over time, making these noises in response to physical exertion or discomfort can become a habitual behaviour. This means that even when the physical effort or pain is minimal, the individual might still produce these sounds out of habit. This habitual response reflects a learned behaviour rather than a necessity, as the person has conditioned themselves to make these noises in specific situations.

Increased exertion and psychological impact
Grunting or moaning might enhance the perception of exertion. Similar to athletes who grunt during high-intensity activities to boost their performance, older adults might use these sounds to help them feel more powerful or capable during everyday tasks. The psychological impact of making these noises can create a sense of increased effort and significance. By grunting or groaning, individuals might feel as though they are engaging more deeply in the physical task at hand, which can provide a mental boost and make the effort feel more substantial. This aspect underscores how these sounds might serve both a physical and psychological function, helping older adults feel more engaged in their movements.

In summary, the articles explore how core muscle weakness, breath control, pain, habitual responses, and psychological factors all contribute to the grunting or moaning sounds older adults make during routine activities. These themes collectively offer a comprehensive understanding of why these sounds occur and how they are related to the physical and psychological aspects of aging.

Please note: This information comes from online articles, not peer-reviewed research.

Links:
https://www.dougkelsey.com/grunting-aging/
Why You Make Grunting Noises Every Time You Sit, Stand And Bend Over | HuffPost UK Wellness (huffingtonpost.co.uk)
What’s Behind the ‘Middle-Aged Groan’? – The New York Times (nytimes.com)
Why do I grunt when I bend over? (theconversation.com)
Why Do Older People Grunt or Moan While Sitting Down or Standing Up? (mentalfloss.com)
This is why you grunt when you bend over – ABC News