番茄社区

With yet more evidence coming out against prolonged sitting -- most recently from a meta-analysis tying 10 or more hours of sedentary time per day to -- many are taking to "standing desks" at work.

But is that really the answer? We asked cardiologists and primary care experts via email:

Do you recommend standing desks for patients who do office work, and do you justify this on the basis of specific evidence or does it just make sense a priori?

How much influence do you think you have on patients' physical activity? What proportion of them take your advice on exercise and other lifestyle factors?

To what extent is it inevitable that people will adopt sedentary habits given an economy that increasingly emphasizes "knowledge work" over physical labor, and what can society and government do about it?

Weighing in were:

, professor of medicine; medical director, Cardiac Rehabilitation and Preventive Cardiology; director, Exercise Testing Laboratory at Ochsner Health System in New Orleans

, internal medicine physician at One Medical Group in New York City

, associate professor of clinical medicine at Weill-Cornell Medical College in New York City and associate clinical member at Houston Methodist Research Institute in Houston

, associate professor of medicine at University of Massachusetts Medical School in Worcester

, assistant professor of medicine (cardiology) at University of Mississippi Medical Center and associate director for clinical research at Mississippi Center for Heart Research in Jackson, Miss.

Standing Desks

Lavie: It makes sense as many studies and meta-analyses indicate that prolonged sitting is bad and standing or even walking desks would not count as sitting.

Thaler: We humans evolved long ago to be hunter-gatherers, and evolution, it seems, hasn't had sufficient time to select for those of us who are the best sedentary-ruminators. It's therefore hardly surprising that exercise and activity of any kind is good for us, whereas just sitting around is not. What is surprising, perhaps, is that exercise alone doesn't by itself appear to overcome the disadvantages of sitting much of the day -- no matter how much we exercise, we still need to move frequently throughout the day, both at home and at work. The most recent analysis suggests that the risks of remaining sedentary kick in at about 10 hours. So if you work at a desk and watch TV for a couple of hours at home in the evening, this means you. So it is time for all of us to get up off our chairs and move. If a standing desk does it for you, then -- even though there is as of yet no compelling evidence pointing specifically to standing desks as mitigating the risks of heart disease, cancer and diabetes associated with sitting -- I am all for it.

Septimus: I don't know of any evidence that standing desks are clinically proven to be of benefit. Further, standing by itself doesn't do nearly as much as getting up and walking around! I recommend patients who have desk jobs get up every hour and take a walk. Additionally, going for a 30-minute walk at lunch helps really get the body moving.

Ma: I do not recommend people standing who do office work, as I do not think there is evidence supporting this recommendation. In this publication, they found a nonlinear association between sedentary time and risk of CVD, while the association was only observed for more than 10 hours of sedentary time per day. In addition, the studies included in this meta-analysis were only observational studies, which can't control all potential confounding factors (i.e., people who had more sedentary time may be less healthy and older). Clinical trial data are needed for the evidence to support the recommendation. For example, a clinical trial that we can randomly assign a group of healthy subjects into several groups of office standing hours/day, and follow them up for adverse CVD events to compare the risk. In addition, we also need to look into adverse effects as well, e.g., long standing hours can cause varicose veins. Special population, such as pregnant women and old adults with chronic diseases, may not be appropriate for standing for long hours.

Hall: I have not recommended standing desks yet. Reducing sitting time is important, but I'm not sure how much simply standing instead is beneficial. There is certainly benefit from increasing physical activity and minimizing the time spent in sedentary activity. However, there is accumulating evidence that increased sitting time (or sedentary activity) is independently associated with adverse health consequences beyond physical activity. Other breaks in sedentary activity at work could include frequent walking breaks (i.e., every hour) or some sort of actual movement -- even little things like fidgeting, stretching and other non-exercise activity have health benefits. Although standing seems to burn a few extra calories compared with sitting, I think incorporating some actual movement makes more sense. Other little things like taking the stairs at work can probably have benefits also.

Physician's Influence

Thaler: In my experience, the impact a healthcare provider has on his or her patients is directly correlated with the ease of communication – and this goes both ways: the physician must above all be a good listener -- and the bond of trust between them. When there is this kind of rapport, then healthcare providers can have a large impact on patient's lifestyles, including physical activity. I've had the privilege to see patients turn their lives around through continued conversation and encouragement.

Hall: I think patients place a great deal of weight on what their physician recommends. If your doctor won't tell you what you need to do to get healthy, that is a big problem. Many patients assume they are doing just fine unless their doctor mentions a specific problem. A significant number of physicians do not advise their patients to increase their physical activity and, unfortunately many patients don't heed their doctors' recommendations for things like increasing physical activity or dieting. Currently, the CDC estimates that 70%-75% of adults in the United States get insufficient physical activity to maintain good health. Lifestyle changes, such as setting a schedule for regular physical activity, can be hard to initiate and take frequent coaching by not only their doctor, but also family members, friends or colleagues.

Ma: The compliance of increasing physical activity program is lower compared to dietary modification program, in general.

Lavie: Substantial [influence] – I published a paper in Mayo Clinic Proceedings in 2013 with Drs. Vuori and Blair on promoting physical activity throughout the healthcare system and Robert Sallis from Kaiser published one in 2015 in Progress in Cardiovascular Diseases and both papers called for documenting physical activity in the medical record and prescribing physical activity to everyone not meeting the current goals. I do not think that just because I do this makes every patient achieve the goal, but studies do document that this prescription leads to an increase in physical activity in substantial numbers of patients to goal or at least closer to goal. This has certainly also been shown with promoting smoking cessation.

Septimus: The reality is that primary care docs don't have as much influence as we'd like, but I do think my advice is critical. Even if my patients don't follow my recommendation, which is to exercise 5 days a week, many of them will at least begin to increase activity. Every little bit helps! Where I feel we have much less success is with diet. Advice for diet is more complex, more difficult to follow, and nearly impossible to maintain for the long-haul when every fast food restaurant has a dollar menu for the most unhealthy options around. It's frustrating. But the more we discuss it with patients over the years, the better understanding they have. I would say the vast majority of my patients at least try to take steps that will improve their health based on my recommendations. It's almost never that they take ALL my advice, however.

Societal Overhaul

Ma: Unfortunately, people will adopt sedentary habits with "knowledge work" emphasized over physical labor. In general, sedentary lifestyle is one of the risk factors for CVD. I think government and society should encourage and create opportunities for exercise break during office hours, including creating safe walking paths, parks and gyms within and around office buildings.

Septimus: Choice is key in our economy, so I think we need to educate consumers on healthy choices and try to incentivize patients to live a healthy lifestyle. Employers are already doing this: Houston Methodist, for example, does nicotine testing and encourages a lifestyle track for all employees. The reward is a discount on health insurance premiums. I think employers like Houston Methodist are leading by example in providing POSITIVE incentives for employees to improve their health!

Thaler: Sedentary work in today's world is unavoidable for most of us, but there is a great deal we can do to mitigate the harms. ... Companies would find that by encouraging these behaviors by their employees will be more focused and productive at work as well as healthier and happier.

Hall: The shift toward less physical labor and more "knowledge work" which involves less physical activity certainly contributes to a sedentary lifestyle. Many companies (even big tech companies with computer-based jobs) have incorporated and encouraged physical activity breaks at work. Increasing access to gyms and walking trails at work are obvious ways to encourage physical activity and break up the sedentary day. Societies can, and have, increased physical activity by encouraging things like biking or walking to work instead of taking motorized transportation. Another big opportunity is incorporating physical activity into the regular day early in students with physical education. This is arguably as important as learning math or science.

Lavie: I think that there needs to be a constant promotion. Schools need to promote it for their students, with mandatory PE. Parents need to promote it for their kids and be good examples. Employers and Industry are already promoting it by having exercise rooms on campus or having employees wear pedometers and give rewards or reductions in healthcare premiums to those who achieve high physical activity, with the idea that this will reduce healthcare costs and improve work productivity. Potentially, the government could also reward achieving high physical activity in some way, potentially with tax savings or if government is more involved with healthcare, with savings on premiums.

Comment