Regular exercise won’t save you from the dangers of sitting

You’ve probably heard the phrase “sitting is the new smoking”. A strong and attention capturing statement indeed and one that implies a familiar activity has deleterious effects on our long-term health. Perhaps conjuring thoughts in the reader of diseases associated with smoking such as cancer and heart disease. One may also infer that sitting is addictive, that the comfortable looking armchair is luring us seductively to an early grave.

I want to find out if there is any merit to this attention-grabbing headline and if so, what we can do to protect ourselves from the ravages of…sitting?

 

What are the dangers of sitting?

Health problems associated with sitting

Sitting is associated with four or perhaps five of the leading causes of death in the US today.

 

The safeworkaustralia.gov.au website does a great job of summing up the health problems that are associated with prolonged sitting: musculoskeletal disorders, cardiovascular disease, diabetes, obesity, poor mental health, some cancers and premature death.

The same website suggests that the above health problems arise due to these issues connected to sitting:

  • insufficient movement and muscle activity
  • low energy expenditure
  • not moving enough
  • not changing posture enough.

The top ten current causes of death in the US, according to a list published in Medical News Today are:

  1. Heart disease
  2. Cancer (malignant neoplasms)
  3. Chronic lower respiratory disease
  4. Accidents (unintentional injuries)
  5. Stroke (cerebrovascular diseases)
  6. Alzheimer’s disease
  7. Diabetes
  8. Influenza and pneumonia
  9. Kidney disease (nephritis, nephrotic syndrome, and nephrosis)
  10. Suicide.

 

If we cross-reference the lists above, sitting is associated with four or perhaps five of the leading causes of death in the US today, including three of the top five. This is beginning to look pretty damning for sitting. Can sitting possibly be this dangerous?

Before we continue, we do need to consider the type of research carried out when studying sitting. You may have noticed that the word “associated” has been italicised in the preceding paragraphs. That sitting is associated with the risk factors mentioned. Associated with (or correlated with) is different than caused by, “correlation is not causation” goes the phrase. What researchers have found is a relationship between sitting and for example, cardiovascular disease.

 

Different types of research

An important side note to keep in mind when reading articles that discuss research, including this one!

Randomized Controlled Trials

The gold standard research method, particularly when it comes to studying medical interventions are Randomized Controlled Trials or RCTs. RCT’s however are not ethical to use when studying the causes of a disease: forcing one group of subjects to sit for ten hours a day when you believe sitting may cause serious health issues is considered unethical!

Cohort studies

What researchers can use in these circumstances are cohort studies, which can be used to help investigate the causes of diseases. Cohort studies cannot provide definitive proof that prolonged sitting causes cardiovascular disease but they can reveal strong evidence of an association between prolonged sitting and CVD. Other variables may play just as much or indeed a greater role in causing CVD, in other words other factors beyond sitting may be at play despite the strong association.

Observational studies

Just because there is a correlation doesn’t mean there is a causation, otherwise we would need to consider banning Nicolas Cage films to reduce the number of swimming pool drownings. We can see that it is very possible for unrelated factors to be tightly correlated. However, this doesn’t mean that we should ignore observational studies or throw out the baby with the bath water, only that we need to approach the results of observational studies with a degree of healthy scepticism and good old fashioned common sense. And it is common sense to believe physical inactivity may be problematic for the human physiology, immobilized muscle tissue for example begins to atrophy significantly within hours. It should not be controversial then that inactivity is bad for us.

 

What the observational research suggests

Research published in the Annals of Internal Medicine on 12th September 2017 concludes that sitting for long periods of time is “a risk factor for early death.” And perhaps surprisingly the researchers found that this appeared to apply to individuals who exercise regularly just as much as those who don’t. Regular exercise apparently did not mitigate the damage of prolonged sitting.

This is in line with earlier research published in 2012 that suggests individuals who exercise spend just as much time sitting as those who don’t exercise– an average of around nine hours per day. The 2012 paper also found that exercisers have a tendency to be less active overall on the days that they train- possibly because they feel they have already done their “bit” for the day.

The cohort study published in 2017 also suggests it is not just the total length of time per day that we spend sitting that is damaging, but also how long we sit for at a stretch. Individuals in the study who sat for a maximum of 30 minutes at a time fared much better than those who sat for longer; they were more likely to be healthy and decrease their chances of early death regardless of Body Mass Index (BMI), sex, age or exercise habits.

Extended periods of sitting cause the metabolism to significantly slow down and behave differently from a healthy active metabolism and bouts longer than 45 minutes are potentially damaging to the bones and muscles.

 

Is standing any better?

When the “sitting is the new smoking” headlines first hit the press 5 years ago, one of the instant responses was an increase in the popularity of standing to work and as Businessweek reported in 2012 the world’s biggest office furniture manufacturer saw standing desk sales grow four times more than that of regular desks.

Many health-conscious individuals went from sitting for most of the working day to standing for most of it. As it turns out, this is not ideal either as too much standing can be excessively tiring, increase the likelihood of developing varicose veins and places a much greater load on the circulatory system. Website safeworkers.co.uk points out that back pain is also far more prevalent in workers who stand for most of their working day rather than sit.

And anyway, as Keith Diaz, lead author of the 2017 research paper, points out there is little evidence to support the use of standing desks to mitigate the negative effects of sitting.

Standing all day may not be the solution, to the sitting epidemic and at least when we do sit or stand, we should be doing so in correct posture. Click on the image below to enlarge it and read the small print.

 

Alternate between sitting and standing every 30 minutes. Illustration by Elenabsl.

Alternate between sitting and standing every 30 minutes. Illustration by Elenabsl.

 

Mixing it up

A suggestion made by some is to alternate sitting and standing every 30 minutes, this is a strategy that I like and indeed do myself. However, if we take the research at face value just alternating between sitting and standing is not going to provide the potential health benefits we need. There is a missing element… movement. And this element is probably far more important than adding standing to the mix alone. If you haven’t already got a standing/sitting desk yet, there is probably no need to rush out to get one.

What is most likely to counter the negative effects of sitting all day at a desk is interspersing all that sitting time with “movement breaks”. Researchers suggest taking a movement break for every 30 consecutive minutes spent sitting, a simple timeout of 1-5 minutes to awaken your physiology, allowing you to return to your desk enlivened!

 

Movement break suggestions

A brisk walk
Qi Gong
Gentle joint mobility movements
Performance of a biomechanically sound strength training exercise in a slow and controlled manner

If you’ve never heard of Qi Gong before, here is an old video of me doing eight Qi Gong exercises in the garden. They are great for the body and mind too 🙂

 

The big picture

It is very important to have good foundations underpinning your physiology for daily existence: a strong, capable and pain-free musculoskeletal system. One of the best ways that you can ensure that you develop this is by regular performance of well-structured high intensity resistance training (HIT) routines.

Doing this will help you to sit, stand and move appropriately without experiencing undue fatigue or pain, then add mini-movement breaks to your daily life to lubricate the system and avoid the potential damage of too much prolonged sitting.

Sitting may not be the actual cause of early death it may just be an association, maybe there are stronger underlying causes, but sitting as much as we do in the modern world probably isn’t that great for us and we have little to lose and potentially much to gain by interspersing our day with micro workouts or simple movements.

 


References
1. Association is not the same as causation
2. What is a cohort study in medical research?
3. Spurious correlations
4. Effects of bedrest 3: musculoskeletal and immune systems, skin and self-perception
5. Sitting is the new smoking even for runners
6. The facts: the human body is designed to move
7. The Trouble with Chairs: The science of being sedentary and how much it does (or doesn’t) affect your health and back pain
8. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women
9. A Cluster RCT to Reduce Office Workers’ Sitting Time: Impact on Activity Outcomes.
10. When It Comes To Desks, Sitting Is Bad, But Standing May Not Be Better

 

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This article was posted on September 20, 2017 by in Health and Fitness, How-tos, Videos


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