The ‘shiver’ diet? Don’t we wish

We hardy inhabitants of the Snow Belt have joked for years about the calories we (theoretically) burn from shivering our way through winter.

But wait – could there be scientific evidence supporting shivering as a hot new form of winter exercise?

Apparently so, according to the New York Times, which reported today on a study suggesting that shivering boosts the metabolism in the same way that exercise does.

Study participants were brought into a lab on three different occasions. During the first two sessions, they were told to exercise on a stationary bike in an indoor temperature of 65 degrees, and samples of their blood, fat and skin cells were obtained. For the last session, the participants were instructed to lie down, lightly clad, for half an hour while the indoor heat was reduced from 75 to 53. Their skin and muscle reactions were measured and samples taken again to see what happened.

Lo and behold, the study subjects produced the same amount of irisin, a hormone involved in the conversion of white fat cells to more desirable brown fat, from shivering as they did from exercise.

From the article:

What seemed to matter, the researchers concluded, was not the exertion of the exercise, but the contraction of various muscles, which occurred during shivering as well as cycling.

In view of the fact that the temperature this morning on my way to work was 0 and most of Minnesota is under its umpteenth wind chill advisory of the season, readers will have to excuse me for not climbing enthusiastically onto the shivering-as-a-form-of-exercise bandwagon.

A variety of studies have shown that we do indeed burn more calories when we’re trying to stay warm. But whether this is an appropriate substitute for exercise is debatable, especially since the study described by the New York Times only involved 10 people – hardly enough to build a strong scientific case. And the article does in fact offer an important caveat: There seems to be no evidence that working out in the cold helps rev up the production of irisin anymore than exercising in warmer temperatures.

In a sentence that could only have come from someone blithely unaware of the dangers of frostbite, the author concludes that if you can’t get to the gym, “at least consider lingering outside at the bus stop and shivering.”

No, thanks. I’ll take indoor exercise over lingering at the curb with a minus 25 breeze in my face any day.

Tribune photo by Ron Adams

The exercise conundrum

We all know physical activity is supposed to be good for us, yet approximately 40 percent of the American population reports not exercising at all. How come?

The New York Times reported a couple of days ago on some intriguing research that might shed a little light on this riddle: When people avoid exercise, maybe it’s because some forms of physical activity leave them feeling bad rather than good.

How this works seems to be complicated. In a series of studies, the researchers found that people had different reactions to the increasing intensity of exercise. Some felt better the harder they exercised; others felt worse. The majority of them felt bad when they surpassed their “ventilatory threshold,” or the point at which they were breathing too hard to talk – and this threshold was different for everyone.

In another study, volunteers were asked to exercise for 20 minutes at a level that felt unpleasant to them. In one session they were given a five-minute cool-down afterwards that restored their sense of well-being. In the other session, they were told to stop exercising without cooling down. When asked later which of the two workouts they preferred, most chose the one that left them feeling more pleasant.

In some ways this shouldn’t come as a surprise. People tend to pursue activities that make them feel good and avoid those that don’t.

The more intriguing part is that we seem to be learning that exercise, like weight management, may not be a one-size-fits-all matter of “just do it.”

While the vast majority of people derive health benefits from regular physical activity, there clearly are differences in how it’s perceived and experienced.

Some people seem wired to enjoy exercise more than others do, and research suggests there indeed may be individual variations in how the body responds physically and emotionally to exercise. Some runners, for instance, experience the fabled “runner’s high,” while others don’t. Then again, perhaps individual behavior is largely to blame for why so many people don’t engage in exercise.

Or is it more complicated than this? Reader responses to the New York Times article provide a wider perspective on what might be going on in people’s lives to make the recommended 30 minutes of daily physical activity so difficult for many of them.

One person lived in San Francisco for many years, didn’t own a car and walked everywhere. Then he moved to Florida, to a town where “a car is needed for even the smallest errand,” and watched his weight, cholesterol and blood pressure soar. Others described neighborhoods with no sidewalks, streets that are poorly lit at night, bike paths littered with glass, and gyms and fitness centers that are either unaffordable or only open during the day.

Some commenters wrote that for many non-exercisers, the problem is in getting started. What they need is help, patience and encouragement, one person wrote. “There is so much anxiety tied up in this issue for people who are out of shape, they don’t know where to start and the idea of exercise feels overwhelming and genuinely terrifying.”

And what about the tendency for issues such as arthritis, chronic insomnia, low-level depression or long, stressful work hours to undermine people’s willingness to be more physically active? One commenter, who had frequent severe migraines and also worked long hours, wondered, “How is one supposed to exercise?!?! and eat? and sleep? and be a person… of sorts?”

Several commenters also complained about the sniffy elitism that can pervade the conversation about exercise – for instance, value judgments about what constitutes “real exercise.” Don’t shame people for not being able to engage in a high-intensity workout, wrote one woman, who said she’s over the age of 60 and has painful arthritis. “Judging other people’s exercise habits doesn’t make them want to exercise more, it just makes them feel bad.”

Someone else pointed to the unrelenting hideousness of phys ed classes in junior high that were rigid and competitive rather than fun. “Maybe that is why I came to hate exercise and it still feels like punishment,” she wrote.

So what’s the answer? It seems to come down to making physical activity more rewarding and less of a struggle. How this is supposed to be accomplished might be different for everyone – and, as with the national effort to reduce the incidence of obesity, some of the solutions will likely have to take place in the environmental and policy sphere. Figuring out why some people genuinely enjoy exercise and find it pleasurable and why others don’t might be a good start, though, at understanding these differences and coming up with effective strategies to help.

Linkworthy 4.0: The overdue edition

I’m way overdue for another edition of Linkworthy, my semi-occasional collection of links to interesting health-related stuff recently encountered on the web.

Besides, it’s time we all moved on from the Hatfield-McCoy post, which has accumulated several thousand hits since being published three days ago and is perhaps in need of a rest. (I’m just sayin’.)

Regional news first: The latest issue of Prairie Business Magazine includes a cover story about the use of high-tech diagnostic imaging, how the technology has evolved and how it’s being used in daily care. As a bonus, there’s also a story exploring the demand for doctors in rural health.

Did anyone catch the news earlier this week about a proposal by Michael Bloomberg, mayor of New York City, to ban extra-large soft drinks? On the surface, this might sound like a good tactic in the so-called war on obesity. Many people are questioning, however, the likelihood that a ban on large sodas will make much difference. The critics have weighed in here and here. The most colorful quote probably comes from the online commenter who opined that “we are like a bunch of lemmings headed for tyranny.”

Speaking of obesity, few people could have failed to miss the recent news about a study that discovered exercise does not in fact benefit everyone. Researchers analyzed six earlier studies and found that in about 10 percent of the participants, heart-related measures such as blood pressure, insulin level, cholesterol and triglycerides worsened with exercise.

The spinmeisters have been hard at work. Some are pointing out, and rightly so, that this was only one study – and a relatively small one, at that. Others worry that folks will use it as an excuse to avoid exercise. What this study really seems to be saying, however, is that we need to be careful about cookie-cutter assumptions that a particular intervention or lifestyle is always good for everyone, because often there are exceptions to the rule.

After blogging about three years ago on needle phobia, I heard from a couple of people who have this fear and who felt their anxiety often wasn’t taken seriously by health care providers. So I was intrigued to come across the news that MIT has developed a high-powered liquid injection device that squirts a thin stream of medicine directly into the skin.

According to the developers, it’s so fast and precise that it can barely be felt. But it’s a little premature to hope the device could be coming soon to a health facility near you. The injector device is still in the prototype stage and hasn’t yet been tested on humans. There’s also the not-insignificant matter of cost. Nevertheless, it’ll be interesting to see whether this Star-Trekkian concept catches on.

Most of us have probably heard about Munchausen’s disease, or Munchausen by proxy, in which people go to great lengths to fake illness in themselves or someone close to them. Now it seems there may be a new version of this behavior: Munchausen by Internet.

A rather chilling story from the BBC News Magazine details the behavior – and impact – of individuals who go online and convincingly pretend to be sick or to have someone in their family who is sick. Some of these hoaxes can be incredibly elaborate – for example, a woman in the U.S. who faked having cancer, HIV, anorexia and heart problems, and went so far as to post online pictures of herself in a hospital bed with an oxygen mask and feeding tube.

Many fakers seem to crave attention, and the Internet is the ideal medium for their manipulations, the article notes. “It gives the perpetrator a quick hit of attention, a feeling of being valued, but without really having done anything to deserve it. Just as online fraudsters dream of easy money, these people crave easy attention. And it is, perhaps, just another form of fraud – emotional, rather than financial fraud.”

Consider setting aside a chunk of time for the final piece in today’s series of links, an in-depth look at the huge global business of tobacco smuggling. Cigarettes are the most widely smuggled legal substance in the world, generating multibillion-dollar profits, fueling organized crime and corruption, and diverting much-needed tax revenue from governments.

Since 1999, a team of reporters with the International Consortium of Investigative Journalists has been examining this issue. They’ve just published a new series of reports, assembled by journalists from 15 countries, that takes a look at the influence of organized crime and terrorists groups as well as “the continued complicity of distributors, wholesalers, and tobacco companies themselves” in the illicit tobacco trade.

Most people are likely unaware of the impact of tobacco smuggling, its ties to crime and its impact on developing nations where cigarettes increasingly are being introduced and sold on the black market. This ambitious news project explains what’s happening and, more importantly, why it matters.

The sedentary life

Next to my computer at home is a kitchen timer. If I plan to spend part of my weekend at the computer, I set the timer for 30 minutes. When it goes “ding!” I know it’s time to turn off the computer and go do something else.

This was one of my New Year’s resolutions this year – to limit how long I sit at the computer and, by extension, to be more physically active.

It’s pretty amazing how much time we spend sitting on our duffs. Television and video games seem to get most of the blame but I think there’s also something else going on: the amount of time, by necessity, the average adult spends in front of a computer screen.

I mean, think about it. We pay our bills online. We do our taxes online. We bank and shop online. We follow the news online. If you’re like me, e-mail and Facebook are probably the main ways you stay in touch with family and friends. (Then there’s my little addiction to Farmville… but I don’t wanna talk about that right now.) One way or another, it’s not hard to rack up a lot of time, on a daily or weekly basis, being sedentary while we deal with the mundane routine of life.

I’m not suggesting we banish computers from our lives. The issue is one of moderation. What’s worth noting here is the importance of moving around – not necessarily running marathons but just being reasonably active throughout the day.

It’s pretty hard to ignore the evidence that has piled up over the years consistently demonstrating that a non-sedentary lifestyle is linked to better overall health and better quality of life. The most recent additions to this body of knowledge appeared a few months ago in the Archives of Internal Medicine in the form of several published studies, most of them looking at the effects of exercise on aging. In an accompanying commentary, the editors note that “the promotion of physical activity may be the most effective prescription that physicians can dispense for the purposes of promoting successful aging.”

Among some of the benefits: improved cardiovascular health, increased endurance, stronger bones, better sleep, reduced stress and better ability to manage weight.

In the national public-health clamor over obesity, it often seems we’ve become so hung up on the numbers on the scale that we’ve lost the ability to put them into context. Yes, we need to do something about obesity. But physical activity is equally a predictor – maybe even more so – of lifelong health. It’s possible, after all, to weigh the right amount yet not be very physically active. It’s just as possible to be overweight in spite of relatively consistent exercise. If I had to pick which of these two examples denoted better overall health, I’d go with the person who maybe weighs a little too much but is physically active.

Getting a move on is not easy. We live in a fast-food environment that makes it difficult to eat as well as we could, and we live in a technological world that makes it difficult for us to be as active as we should. I’m not going to give up my computer any time soon, and in fact I would be at an enormous social disadvantage without it. But we need to be mindful and seek some balance. Sometimes all it takes is setting a timer and then going outdoors on a sunny April weekend and weeding the garden instead.

Image: I Can Has