Vitamin C, not D, helps acute-care hospital patients

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As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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Over the past few years, I’ve become increasingly skeptical about the benefits of taking vitamin C (and other antioxidant) supplements. On the other hand, vitamin D research has looked increasingly promising. So here’s a study from Montreal’s Jewish General Hospital that suggests I should keep my mind open:

In a double-blind clinical trial, patients admitted to the JGH were randomly assigned to receive either vitamin C or vitamin D supplements for seven to ten days. Patients administered vitamin C had a rapid and statistically and clinically significant improvement in mood state, but no significant change in mood occurred with vitamin D, the researchers discovered.

Now, this is a fairly specific population being studied, so the results aren’t generalizable. Apparently about 20% of the acute-care patients in that hospital “have vitamin C levels so low as to be compatible with scurvy,” so it’s not surprising that vitamin C helped. Ultimately, this is simply more evidence that supplements are useful for treating deficiencies; it doesn’t say anything about whether supplements provide any benefits for healthy people.

Your neighbourhood affects your BMI — in unexpected ways

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As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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Researchers at the University of Alberta just published some interesting data from a six-year longitudinal study looking at links between neighbourhoods, physical activity and body-mass index. Of the people who moved during the study, those who chose new neighbourhoods based in part on walkability maintained their weight (as expected), while those who chose locations based on proximity to outdoor recreation opportunities (surprisingly) gained weight.

This is by no means a perfectly controlled experiement — for example, as the researchers point out, it could be that the subjects choosing to live near outdoor recreation were doing so primarily for their kids. But it certainly fits with other data, like the fact that New York City — highly walkable but terrible for outdoor recreation opportunities —  is among the thinnest cities in the U.S. (42% of people there were overweight, compared to 67% nationally, according to a 2009 study). And it underlines the point that a healthy lifestyle is more dependent on the little things you do on a daily basis, rather than the big excursions you make on weekends.

Circadian rhythms and athletic performance

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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The latest Jockology column is posted on the Globe and Mail site (it won’t actually appear in the paper until this coming Thursday due to a schedule change, so you’re getting a sneak peak online!). The topic is circadian rhythms — how they affect physical performance, and how you can alter them. An excerpt:

[…] A 2007 study by Tunisian and French researchers found that power in an all-out 30-second cycling test was lowest at 6 a.m., then increased steadily through the day until it was about 10 per cent higher at 6 p.m., then fell steadily. A long list of earlier studies had found similar effects in back and arm strength, vertical and broad jump, and also in sports ranging from swimming to badminton, with the peak time always within a few hours of 6 p.m.

This effect may be partly a function of time awake (you’re groggy early in the day and tired later in the evening) and eating patterns (you won’t be at your best before breakfast or immediately after lunch).

But more subtle circadian rhythms, such as the daily change in core body temperature, also play a role, Dr. Sleivert says. Studies have found that body temperature rises by about 1 C between early morning and late afternoon, which may help loosen muscles and swell blood vessels in the same way a pre-exercise warm-up does… [READ THE WHOLE ARTICLE]

A related topic is how athletes deal with jet-lag, which is covered in an info-graphic that accompanies the piece (but doesn’t seem to be included online). I looked into some of the research on melatonin (the hormone that basically tells the body that it’s nighttime), and found it convincing enough that I decided to give it a try. By coincidence, I flew to London last night/this morning, so I’ll have a chance to give a try when I go to bed in a few hours. Here’s hoping for a melatonin miracle and a good night’s sleep!

Being a sports fan in the Internet age

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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A quick plug for my cover story in the new issue of Maisonneuve magazine, a 5,500-word essay on how the relationship between sports fans and their heroes is changing in the Internet age. It’s a piece that I started developing as a writer-in-residence at the Banff Centre, which gave me the luxury of time to think about and research this idea in depth. The article itself isn’t available online, though the opening paragraph is posted — along with a YouTube clip of the 1500m final at the 1996 Canadian Olympic Trials, which was a pretty embarrassing moment for me but significant in terms of the ideas I look at in the article. You’ll have to read the article (in the paper version of the mag) to find out why!

Massage lowers stress hormones

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

Massage is a multi-billion dollar industry these days, as a new study in the Journal of Alternative and Complementary Medicine points out. Apparently 8.3% of adults in the U.S. got at least one massage in 2007, “as a treatment for a myriad of conditions ranging from muscle aches, back pain, headaches, and insomnia, to psychologic stress, anxiety, and depression.” But does it actually do anything? It’s a very difficult topic to study, though a few researchers have started to make headway.

The new study, by researchers at Cedars-Sinai Medical Center in Los Angeles, is an interesting one. They gave 53 volunteers either a standard 45-minute Swedish massage (using the “core massage techniques of effleurage, petrissage, kneading, tapotement, and thumb friction”), or 45 minutes of “light touch” therapy using the back of the hand. The hypothesis was that massage would lower stress hormones such as cortisol by increasing levels of oxytocin, the “cuddle hormone” that is involved in bonding, maternal behaviour and a host of other behaviours.

What they found was that cortisol did drop, by 32% in the massage group and 21% in the touch group — so massage was “better.” But oxytocin couldn’t explain the change — it fact, it increased more in the touch group (12%) than the massage group (9%). So the conclusion (in press reports, at least) is that “massage benefits are more than skin deep“; the paper itself concludes that “these findings may have implications for managing inflammatory and autoimmune conditions,” but not through the mechanism they originally expected.

My take: this is not surprising. I would have been astounded if massage didn’t lower cortisol levels. After all, listening to music or getting a nice compliment can lower your cortisol — but we don’t claim that these things can heal muscle pain! What’s most interesting about this study is that the controls received “light touch” therapy, which likely triggers many of the same bonding responses. This gives us the chance to see how much of the effects of massage are due to the pleasurable social/bonding interaction, and how much is due to “effleurage, petrissage, kneading, tapotement” and so on. And the differences aren’t as big as you might hope.

That being said, this study’s outcomes are mostly about general “wellness” rather than sports-related benefits — there’s nothing that tells us what’s happening to muscle fibres and so on. Still, it is (as the authors note) an important first step to separating the general benefits of having someone rub their hands all over you from the specific benefits of certain massage techniques. Hopefully we’ll see more studies like this in the future.