We all know that Einstein was a genius – but did you know that he thought of the formula e = mc2 whilst riding a bike? And that one of his most famous quotes is: “Life is like riding a bicycle. To keep your balance, you must keep moving”!
Prolonged Sitting Can Cause Health Issues!
There has been a lot of publicity recently about “sitting is the new smoking” which is a great way to make people aware that prolonged sitting can be extremely harmful to our health in a variety of ways.
However like many new medical technologies, inventions, and developments, there can be a lot of hype and an overwhelming sense of “miracle cure” when these new products hit the market. The Current Affairs programs on TV seem to have a new miracle product every week! Unfortunately most of these products are not miracle cures, in fact most are simply a waste of money, or at best, lack any direct evidence linking their use to a positive health benefit. Thankfully we live in a very evidence-based world which means as health professionals we have an obligation to do the research and make sure that what we recommend has some scientific or evidence based back-ground.
To begin with, we’ll look at prolonged sitting, where a lot of recent research has been completed.
Dr. James Levine (who is credited with beginning the phrase “sitting is the new smoking”) is director of the Mayo Clinic-Arizona State University Obesity Solutions Initiative (and inventor of the treadmill desk) and has been studying the adverse effects of our increasingly sedentary lifestyles for years and has summed up his findings in two sentences:
“Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death.” Sounds pretty dramatic!
A study published in the journal Diabetologia in November 2012(1) analysed the results of 18 different studies with a total of nearly 800,000 participants. When comparing people who spent the most time sitting with those who spent the least time, researchers found increases in the risks of diabetes (112%), cardiovascular events (147%), death from cardiovascular causes (90%) and death from all causes (49%). Other recent studies have shown a link between sitting and a host of chronic conditions, including diabetes(2) , heart disease(3) and colon cancer(4)
What is really noteworthy in many of these studies is the fact that going to the gym or doing an exercise session every day for an hour DOES NOT appear to offset the effects of the sedentary sitting work day. In other words, you can cycle to work, swim at lunch time and then cycle home, but if you spend the rest of your day sitting down, you may be increasing your risk of developing one of the chronic conditions identified due to this prolonged and excessive sitting time.
Is Standing Better Than Sitting?
Comcare (the federal agency responsible for workplace safety, rehabilitation and compensation) studies show that many workers will spend up to 76% of their time sitting, which we know has its potential health issues. However other studies have shown that 40-70% of asymptomatic people will develop low back pain within 60 minutes of standing. There have been other documented cases of negative effects of prolonged standing such as hip/knee pain, foot discomfort and swelling, general muscular aches and pains, and even cardio-vascular problems. So it’s not simply just a matter of standing all day! Dutch ergonomic guidelines suggest standing periods of less than an hour at a time, and total standing periods across the work day of four hours is considered safe.
To muddy the waters more, researchers at Exeter University and University College London followed more than 5,000 people over a 16-year period and their findings were published in the International Journal of Epidemiology(5). Their main finding: “Any stationary posture where energy expenditure is low may be detrimental to health, be it sitting or standing,”!
This is where it can get so confusing – what do you do?
What Is The Answer?
There is an abundance of research on the health benefits for sedentary workers who are more active throughout their work day. There is also the strong belief that desk bound workers who have the choice to sit or stand receive physical and psychological benefits, and perhaps even helps them with their productivity / concentrations levels, although more evidence for this is required.
What is apparent is that there is no single, ideal body position for working. No working posture is so good that it can be maintained for any length of time without variation. Constant sitting is not the safe alternative to constant standing, and vice versa. For the best health and safety outcome, workers should be able to adopt a variety of positions – that is to have the option to sit, stand, move around and vary the nature of work tasks, therefore regularly distributing loads on different parts of the body.
Out of all the information above it seems that the critical aspect that sedentary workers need to consider is activity! Prolonged sitting is not great for us, but neither is prolonged standing. Substituting half a day of sitting with half a day of standing (eg at a sit/stand work station) may reduce some of the risks associated with sitting (or standing) all day, but both are sedentary postures, and neither encourages regular postural changes or energy expenditure. An hour’s exercise at the end of the day may not offset the effects of a whole sedentary work day.
Possibly the best rule to go by is “the next posture is the best posture”. Keep yourself moving and changing positions as much as you can during your work day, and you’ll be doing everything you can to avoid the risks mentioned above.
References:
- E. G. Wilmot,C. L. Edwardson,F. A. Achana, M. J. Davies, T. Gorely… in Diabetologia (2012)
- Gill, J, Bhopal, R, Douglas, A, Wallia, S, Bhopal, R, Sheikh, A, Forbes, J, McKnight, J, Sattar, N, Murray, G, Lean, M & Wild, S 2011, ‘Sitting time and waist circumference are associated with glycemia in UK South Asians’, Diabetes Care, vol. 34, no. 5, p. 1214.
- Thorp, A, Healy, G, Owen, N, Salmon, J, Ball, K, Shaw, J, Zimmet, P & Dunstan D 2010, ‘Deleterious associations of sitting time and television viewing time with cardiometric risk biomarkers’, Diabetes Care, vol. 33, no. 2, p. 327.
- Boyle, T, Fritschi, L, Heyworth, J & Bull, F 2010, ‘Long-term sedentary work and the risk of subsite-specific colorectal cancer’, American Journal of Epidemiology, vol. 173, no. 10, pp. 1183-1191. 8
- Richard M. Pulsford, Emmanuel Stamatakis, Annie R. Britton, Eric J. Brunner and Melvyn Hillsdon1 Int. J. Epidemiol.(2015) 1-8.
