Thursday, October 2, 2014

Should children be using standing desks in schools?

"Sitting is killing you." It might even be worst for your long-term health then smoking, suggests some research. The headline is a bit sensational (in this case by TIME magazine), but the underlying message isn't. In many respects, movement has been engineered out of our daily lives. Now, I'm not talking about the 30 minute jog in the morning or weight session after work. These are laudable activities. I'm talking about the regular movement involved in our everyday activities - essentially, being on your feet for more then a few minutes. 

One technical fix to move (pun intended) people in the direction of increased activity is a standing workstation. They've been around for quite some time, but have become quite the craze recently. 

What's the point? 

Why should we be standing morel? The answer in many public health circles is less about standing for a long duration of time, but rather getting people out of a seated position because of sitting's link to a variety of long-term health consequences. For example, a number of studies, such as this one, have shown a dose response association between sitting time and death from all-causes and heart disease. The more sitting, the higher the risk. Even more important, these results were found to be independent of leisure time physical activity. In other words, your morning/evening run, cycle, swim, row (insert your activity or workout of choice here) does not make up for the eight hours spent sitting at your desk everyday. A similar study, called the Sax Institute 45 and Up Study, which is the largest ongoing study of healthy aging in the Southern Hemisphere, has found a 40% increased risk of death for adults who sit 11 or more hours per day compared to those who sit fewer than four

Armed with the data, many individuals and employers are making changes. Enter: the standing workstation. More offices have them, and more options are available now than ever before. Some, like this one, can easily shift from a standing desk to a regular seated desk. For employers, it's about trying to minimize ill health-related costs and increase productivity.

Schools, on the other hand, are more of an unknown. Standing desks are still not very common, but new research suggests maybe they ought to be. It's a similar rationale with workplaces. Standing desks would help keep kids healthier and boost learning and academic performance. 

Standing Desks for Kids?
 
A new, first-of-its-kind study that tested the use of standing desks in 24 classrooms in three north-Texas elementary schools showed some interesting results, at least from an energy expenditure perspective. Researchers compared energy expenditure (EE) data and daily step counts for 337 students from two different grades within the three schools. Four different classrooms were measured per grade. Below is a picture of the standing desk used by students in the intervention groups (right) alongside the desk used for the control group (left), which were just the normal desks used at the schools before the study. Two control classrooms had to be excluded from the study because they opted to use exercise balls in place of chairs during the school year. As a result, the number of students in the treatment and control groups were not balanced.




The results?  

It's a mixture of good and bad. 

Good news: 
All students, regardless of gender or ethnicity, took more steps and expended more energy if they used a standing desk compared to those using seated desks. The following two graphs illustrate this point. In addition, students who were overweight or obese had a greater EE of 0.24 kcal/min and 0.40 kcal/min respectively compared to students of normal weight range. (One point of clarification: 1 kcal roughly equals 1 calorie). One could then conclude that from a purely EE standpoint (i.e. not considering the limitations of an energy-based way of thinking - in other words, only calories - about weight gain/loss and metabolic dysfunction), a standing desk is more effective then a sitting one, particularly for those children who are already overweight or obese.  

Students who had standing desks also took more steps per minute on average throughout the day. In the fall semester it was 1.61 steps/minute more among standing versus sitting students. This difference essentially disappeared in the spring semester, though, calling into question whether it was the desk per se that caused the increase number of steps, or simply the fact that it was something new. Similar to EE, greater benefits were observed among overweight and obese students.

Graph of average energy expenditure (measured in kilocalories) per minute by each student.


Graph of average steps taken per minute by students.



Bad news: 
A few points of bad news:

1. The overall effect of the intervention was relatively small. If you take the combined average increase in EE for all students using a standing desk compared to sitting, it amounted to a 0.08-0.16 kcal/min increase. Over a four hour period, this only amounts to an increase of 19.2 - 38.4 kcals. For some perspective, a single cup of fresh-pressed orange juice is 112 calories; a single hard-boiled egg is about 70 calories; and a single slice of Nature's Own whole wheat bread has 60 calories. The basic point is that we're not talking about much here. 

2. A 50% smaller increase in EE was observed among students using the standing desk in the spring semester compared to the fall. Basically, the longer students used the desk, the more they adapted to them, expending less energy.

A few Unanswered Questions

Two significant areas went untouched in this study.

1. Alignment: Standing in an anatomically aligned position requires significant postural muscle strength in the legs, glutes, abdominals and lower back. When these muscles cannot sufficiently support the body in a functional way, bad habits form, impacting overall body alignment. For a crash course on alignment, read Katy Bowman's blog or book titled, Alignment Matters. One specific area she discusses at length, and warrants highlighting, is the role of footwear. A straight line should be able to be drawn from the top of the head, down to the heals, perpendicular to the floor or ground. When one introduces a healed shoe (in other words, the large majority of commercially available footwear today), this changes the angle by which this imaginary line intersects with the ground. The result? Muscles unnaturally shorten, like those in the calf, hamstring and lower back, changing the entire alignment of the posterior muscle chain as a result. Ever have tightness, soreness or pain in your lower back? Tight calves and/or hamstrings could be the cause.

2. Productivity and/or education outcomes: The link between physical activity and improved brain functioning is well established. For more on this, read the book Spark: The Revolutionary New Science of Exercise and the Brain. Exercise essentially turns on parts of the brain associated with learning, creativity, and other executive functions. This is the basic argument for retaining (and even increasing) the amount of physical activity opportunities offered to students during the school day. Though lower impact and less cardiovascularly taxing then say running, standing still has its benefits. Really, anything other then sitting is preferable. Unfortunately, none of these non-health benefits were examined in the study, though the discussion section of the paper says otherwise. Despite the fact that the study did NOT measure any education-related variables, the authors still concluded, "the results of this study and previous pilot studies have established that activity-permissive classrooms...improve behavioral engagement." Popular media outlets picked up on this assertion and expanded upon it, such as Fast Company who ran a story on September 26th about the study with the headline "Standing Desks Are Coming to Schools, To Cure Obesity and Increase Attention Spans." This despite the fact that the study did NOT actually measure attention span or "behavioral engagement."

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I've used a standing workstation for several years now, whether commercially bought or one I rigged up using various office supplies. But, is this something that should be standard practice in schools in the US? Should children be forced to use standing workstations? Should they be given the option? Are standing workstations simply overrated? I'd love to hear your thoughts.

2 comments:

  1. I am all for standing desks. My daughter does a lot better in a standing desk. Just reading through the facts you share I know that most adults sit at least an 8 hour shift. I'm glad I have the liberty to move and have more excercise during the day and with that become more healthy. http://www.standsteady.com

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  2. Thanks for your comment, Hanna. I agree that standing can really help with focus, attention and productivity (not to mention the long-term health implications of sitting). For those who can't stand, structuring short, periodic breaks can be helpful, like working for a focused block of 45-50 minutes and then taking 10 minutes to stand and walk around.

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