My Jockology column in today’s Globe and Mail gets seasonal and looks at five bits of research related to exercising outdoors in the winter. For example:
The challenge: Going bareheaded in the winter is like leaving the lid off your thermos. Classic studies in the 1950s showed that if you wear winter clothes but no hat at 4 C, you lose about 50 per cent of your body heat through your head.
The research: A U.S. Army study published in early 2011 showed that your face is almost as important as the top of your head for heat loss. Volunteers spent an hour in a cold chamber with a wind chill of -20 C; those who wore a balaclava had measurably warmer fingers and toes than those wearing a normal hat. Your body tries valiantly to keep your brain warm by shunting blood away from your extremities toward your head.
Read the whole column here.
My Jockology column in this week’s Globe and Mail takes a look at the surge of interest in standing desks:
Now that we’ve accepted the surprising truth about sedentary behaviour – that sitting at a desk all day wreaks havoc on your health, no matter how much you exercise before or after work – the standing desk is having a moment. Desk jockeys everywhere are rising up.
The cashiers of the world, meanwhile, must be scratching their heads.
“Ask anyone who works in a shop whether they feel good standing all day, or whether they need to periodically sit,” says Alan Hedge, who directs the Human Factors and Ergonomics program at Cornell University in Ithaca, N.Y.
Indeed, prolonged standing has been linked to a long list of health problems over the years: most commonly varicose veins, but also night cramps, clogged arteries, back pain and even (according to one study) “spontaneous abortions” – enough to make you think twice before throwing away your chair. But striking the right balance in your cubicle isn’t necessarily about the furniture, researchers say – it’s about how you use it… [READ THE WHOLE ARTICLE]
My Jockology column in this week’s Globe and Mail takes a look at three questions:
- How do cigarettes help marathoners run faster?
- Why does eating red meat cause car crashes?
- Does caffeine cause breast cancer?
In each case, I analyze studies that seem to “prove” these surprising findings, and identify the errors (cherry-picking data, inadequate statistical adjustment, and fishing expeditions) that lead to these conclusions. Basically, it’s a “how to assess medical research” primer. Read the whole thing here.
(Hat tip to Travis Saunders for his blog post at Obesity Panacea about the smoking study.)
My Jockology column in today’s Globe and Mail takes another look at aging and physical decline:
It’s the chicken-and-egg question of aging: Do we become less active as we get older because our bodies start to break down, or do our bodies start to break down because we allow ourselves to become less active?
For years, it was widely accepted that humans would start getting slower, weaker and more fragile starting in their 30s. But new studies on topics ranging from the cellular mechanisms of aging to the time-defying performances of masters athletes are forcing researchers to question this orthodoxy. It seems increasingly likely that the first signs of decline are more a function of lifestyle than DNA: If you keep using it, you’ll be well into middle age before you start losing it. [READ THE WHOLE ARTICLE...]
One of the studies discussed in the article is this analysis of the finishing times of 900,000 German marathoners and half-marathoners, published last year. The researchers argue that the rate of decline of mid-packers is a better way of judging “natural” aging processes compared to the outliers who set age-group world records. For fun, I plotted the average finishing times of the runners in the German study, and superimposed the curve that you’d get if they declined at the same rate as age-group records. It’s pretty clear that this group of midpackers does decline at a slower rate:
This week’s Jockology column in the Globe and Mail takes a closer look at a neat yoga study that I blogged about last month. I got in touch with Nina Moliver, the researcher responsible for the study, and looked at the data more closely:
When Nina Moliver decided to study the long-term health and wellness effects of yoga for her doctoral research in psychology, one of her professors offered some advice.
“The yoga world doesn’t need more testimonials,” the professor at Arizona’s Northcentral University told her. “The only way you’re going to communicate with the medical community is with numbers.”
Yoga science is a burgeoning discipline, with researchers probing yoga’s effects on everything from stress hormones to skin conditions. But how can a typical four- to six-week study capture the benefits of an ancient mind-body discipline that takes years, if not decades, to master? It can’t, Dr. Moliver concluded – so she decided to take a radically different approach that offers the first quantitative look at yoga’s long-term benefits. And the results of her study are promising for dedicated yoginis…. [READ ON]
One little online extra that I’ll post here is one of the graphs from the study, to give a sense of what the data looks like. Basically, you get data points filling the triangle on the upper left of the graph, while the lower right remains empty.
Here’s how I describe the data in the Globe article:
Interestingly, the most experienced yoginis weren’t necessarily happier or healthier than the happiest and healthiest non-yoginis, at least in the parameters Dr. Moliver was able to measure. “They didn’t find ‘enlightenment’ that others can’t reach,” she says. The biggest differences were at the other end of the scale, in the scarcity of unhealthy or unhappy long-time yoga practitioners.
The latest Jockology column in the Globe and Mail is now available online:
Pretty much every fitness product claims to be “backed by science.” But a recent spate of lawsuits against the makers of Power Balance bracelets highlights how empty these claims can be. Even for companies trying to do the right thing, navigating the complexities of scientific evidence can be a challenge, as the following examples illustrate…
The examples are Power Balance bracelets, Athletic Propulsion Labs’ “banned” basketball shoes, Reebok’s “oxygen-enhancing” ZigTech clothing, Gatorade’s claim that drinks with electrolytes help reduce the risk of hyponatremia, and — my favourite these days — beet juice’s endurance-boosting effects. There’s also a nice supporting graphic from Trish McAlaster.
This week’s Jockology column looks at the physiological differences between land- and water-based exercise — aquafit, water running and activities where you’re vertical in the water rather than horizontal like swimming:
[...] The differences between water and land might seem obvious, but there are some subtleties. For example, the pressure exerted by water against your body is strongest at the bottom of the pool, where your feet are, and weakest at the top. This pressure gradient helps push blood back towards your heart, making its job easier. [Read the whole article...]
The article focuses mainly on the advantages of water-based exercise for people with balance, joint or weight concerns that make land-based exercise more difficult. But there’s a special bonus for pool-running aficionados: a brutal 60-minute workout that Canadian mile record-holder Kevin Sullivan used when he had a stress fracture in his sacrum. He got it from 1984 Olympic bronze medalist (and fellow Michigan alum) Brian Diemer, who relied on it to stay in shape prior the 1984 Olympic Trials — Diemer apparently had a stress fracture and came out of the pool only three weeks before the Trials, but was still fit enough to make the team and go on to medal later that summer.
I did it myself, every third day, when I had a sacral stress fracture in 2004. There’s something about the symmetry of the workout that I love — I’m always surprised when all those parts manage to add up to exactly 59:55.
I did a little crystal-ball gazing (some might call it navel gazing) in my column in today’s Globe, picking 10 topics in sports science that I think we’ll be hearing about in 2011:
It’s January, which means the gyms are full of exercisers resolving that 2011 will be the year they meet their fitness goals. In labs around the world, meanwhile, exercise scientists are resolving to settle some of the fitness questions that still dog us. Here are 10 confusing, contradictory, or just plain complicated areas of exercise science that will see significant progress in 2011… [READ THE WHOLE COLUMN]
Most will be familiar to regular readers of Sweat Science, since I think the best predictor of what researchers will be studying is which topics we’ve been discussing and arguing over the past few years. Needless to say, I’d love to hear suggestions of what I missed — which also doubles as a request for ideas for future columns, blog entries and so on. What sports science topics would you like to hear more about in 2011?
(One “miss” that I’ll mention: I didn’t include the debate over running shoes and the ideal stride, even though I’m sure it will remain a hot topic, because I’ll be revisiting it in a couple of columns next month.)
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!
This week’s Jockology column rounds up a bunch of research on the optimal preparation and training for soccer: the mechanics of kicking, the physiology of repeated short sprints, the psychology of penalty kicks, the optimal warm-up and nutrition, rapid direction changes, etc. It’s in the form of a big infographic, put together by Trish McAlaster, the talented artist I often work with at the Globe. (We’re currently working a pretty cool graphic for the next column — stay tuned!)
Most interesting bit of info in the current column, for me, was this: when you run a short sprint, you get about 20% of the ATP you need from aerobic processes, and 80% from anaerobic processes. But if you keep sprinting (as you would for a soccer game), the third sprint is already 50% aerobic/50% anaerobic, and the “Nth” sprint is 75% aerobic/25% anaerobic. So if you want to be fast late in the game, you need to fuel yourself like an endurance athlete.
(This info comes from Stuart Phillips‘ chapter in the book Sports Nutrition: From Lab to Kitchen. And I actually simplified the info a bit for the column by combining the contributions from phosphocreatine with other anaerobic sources. The actual split for aerobic/anaerobic/phosphocreatine is 20/30/50 for the first sprint, 50/20/30 for the third, and 75/5/20 for the Nth.)