My 10 year old garmin watch officially needed replacement last year.

 

After some research I broke down and bought the least fancy version of the Apple Watch.

 

I’m a tech dinosaur and don’t like constant interruptions so I immediately disabled the notices for text messages, emails, and anything else that I could.

 

One notification that I can’t figure out how to turn off (and secretly kind of like) is the buzzing I get after 30 minutes of continuous sitting, reminding me it is time to stand and move around a bit.

 

This got me thinking about the revolution in sit stand desks that seems to have taken over the office workspace ranging from simple sit stand stations placed on top of your desk, all the way up to walking treadmill desks that some lawyers I know use all day at a low 2.0 miles per hour speed.

 

Obviously there is some intuitive benefit to these things, but is there any solid evidence for sit stand desks?

 

Do they actually reduce workplace discomfort?

 

Lucky for me a recent study was conducted on sit stand stations boasted some grand results in the study abstract that confirmed what I assumed (positive results).

 

However when I actually read the study and looked at the tables and figures I was actually left a bit more perplexed, and was reminded of Dave and my research biostats professor during our graduate studies who always implored us to read the actual studies and tables and ignore the abstracts.

 

This is the first study in a long time where my interpretation of the study results and the strong conclusion stated in the abstract were very different.

 

Let me explain.

 

We all know the negative aspects of sitting around all day. Prolonged sitting is linked to an increased likelihood of chronic illnesses, type 2 diabetes, and even early death where sitting 7.5-9.5 hours or more daily has been previously reported to correlate with an elevated risk of mortality.

 

Yet it’s also been estimated that in the developed world, adults spend over 60% of their waking time sitting at work.  During a single day, office workers estimate that 75% of their TOTAL TIME AT WORK is spent sedentary, typically going more than 30 minutes at a time without an interruption.

 

A secondary impact of sitting around like a bump on a log is the increased risk of musculoskeletal discomfort.  This is just a fancy name for the discomfort you get in your neck, back, shoulders, wrists etc. with prolonged sitting.

 

In fact, 90% of office workers report pain associated with sedentary work postures.   

 

In short we all acknowledge the risks associated with movements like repetitive bending/twisting, working above shoulder height and heavy lifting at work but we assign very little risk to the issues associated with not moving at all and how that impacts your health.

 

So what did this study show us?

 

Well……less than I was lead to believe.

 

This was a 6 month trial of office workers that spent at least 70% of their week on desk related activities in an office (no work from home participants).

 

They randomly assigned the participants and ended up with 19 in each of a control group and intervention group.  They had them fill out of a number of questionnaires to assess pain and disorders and had them continuously wear an activPAL4 activity monitor for 24 hours a day over 7 days both at the start of the trial and at the end after 6 months.  This allowed the researchers to more accurately assess the amount of sitting time daily, but also in specific bouts of 30 or 60 minutes at a time.

 

The control group got an education session on how important standing is during the workday, but that was it.  They were NOT provided a sit stand station.

 

The intervention group got the same information session but also got a sit stand station, and ‘motivational nudges’ via email, on the study website and via short animated videos and testimonials to encourage standing through the day.

 

One of my main complaints with the study was the lack of continuity between the two groups (more later).  The mean age was 43.8 however when you look at the data, you see a VERY wide age range of participants from age 24 all the way up to 60.  To me, there would be a big difference in potential workplace discomfort in someone who has sat at a desk for 35-40 years of working versus someone that just began their career.

 

The study was 76.3% female.

 

I also have significant issue with the BMI and body weight of the 2 groups (again more in a moment).

 

You can group the study in 2 main outcomes.

 

• What I’ll call “global outcomes” which included musculoskeletal pain reduction and something called the need for recovery after work.
• Regional location specific pain reduction. This is breaking down changes over the 6 months in pain in specific regions of the body like the neck, shoulder, and lower back.

 

Reading the abstract of the article you would notice the messily highlighted conclusion below:

 

 

In laymans terms this is saying that the 6 months sit stand desk intervention helped to lower people’s pain/discomfort as well as time to recover following work.

 

Great!

 

But is that REALLY what the study showed?

 

When you look at each individual body region studied there was no change in pain across most body areas: the elbow, wrist/hand, upper back and hip/thigh.

 

In fact, the only real reductions were in the shoulder and lower back where the researchers said ‘almost significant’ findings were shown but still no significant differences BETWEEN groups.

 

Now I’m confused….isn’t that the entire point of the study?  To show differences between groups?

 

In fact, in the paper they even go on to say:

 

“Our results are more in line with the ones suggesting no impact of these interventions on musculoskeletal discomfort, as no time*group interactions were found for any outcome.  Regardless, it is essential to mention that we found time differences in the intervention group for the overall MD (musculoskeletal discomfort) score, while no differences were found in the control group.”

 

Ok ok.  So they are hanging their hats on the fact that despite there being no differences between the groups for any specific region, at least the OVERALL discomfort score and post work fatigue scores were better for the sit stand group.

 

Phew.

 

BUT WAIT!

 

I had lost all confidence in the paper at this point so I dug into their tables and to be honest I don’t love what I found.

 

First, let’s look at the baseline characteristics of the two groups.

 

 

I mentioned earlier that I didn’t love the age range, though at least the two groups had a mean age that was similar.

 

But when I scrolled down to the biometric measurements highlighted below I noticed a couple of things.  First that both groups were significantly overweight.  In fact, via BMI standards, the intervention group was classified as ‘overweight’ but the control group was ‘obese’ on average.  Also, the average weight between groups saw the intervention group over 22 pounds lighter on average!

 

What does this mean?  Maybe nothing.  But it could also be what we call a minor ‘healthy user bias’ where the intervention group is healthier to begin with in general so it somewhat muddies the results when looking for differences between groups.

 

 

Now lets scroll down one additional section:

 

 

 

 

 

This time I want you to look at the difference between the control and intervention group in prolonged sitting over 30 and 60 minutes.  This is what the researchers suggest cause the most issue however at the start of the study the intervention group averaged roughly 20 extra minutes per day in episodes of sitting 60 minutes or more which is around a 17 or 18% difference.

 

Why is this important?

 

Well these folks that got the sit stand desks and were ‘nudged’ to move more were starting from a potentially healthier position, and also started by sitting for longer periods at a time meaning there was definitely more room for improvement.

 

This was seen in the results.

 

 

Here, we see the baseline pain in the only two interventions that had positive results; muskoskeletal discomfort and score NFR which means essentially your recovery from work.  What they failed to mention was that the intervention group had a way higher discomfort score AT THE START of the trial than the control group.  Again, meaning there would be greater opportunity for improvement.

 

And that’s what they found where the mean improvement for the intervention group was 4.89 for discomfort and 4.0 for the control group.  However, even at 6 months, the intervention group still had a far higher discomfort level (8.90) than the control group (5.32).  So yes they had a statistical difference from baseline to the end but in absolute terms in my opinion there wasn’t that big of a difference between the two groups.

 

Does this mean the study is false?

 

Not at all!

 

I just wish they had done a better job of getting similar discomfort scores and baseline health measures between the two groups to draw the conclusions they drew.

 

And what of all the regional body parts like neck pain, back pain and shoulder pain?  There were slight improvements in discomfort in the sit stand group but none got to statistical significance.

 

The authors suggested that reducing sitting on its own may not be sufficient to promote improvements in discomfort symptoms.  You need to decrease sitting time AND increase other types of physical activity.  So try an ‘exercise snack’ as we have described in prior blogs or check out this weeks video blog for a few ideas.

 

Again I’m reminded to never judge a study just by its abstract……Dr. McGregor would be proud.

 

I have to go, my watch just went off demanding that I move.