Daylight savings time increases risk of heart attack. Here’s what you can do to avoid one.

heart-attackDid you know that adjusting the clock up by an hour in accordance with daylight savings time increases you chance of a heart attack?

Circadian rhythms are biological cycles that occur in humans, animals, insects, plants, and even bacteria with a period of approximately (circa) one day (diem). These rhythms are determined internally by a part of our hypothalamus and are synchronized perfectly to our 24-hr days by the sun and other cues. This internal clock mediates daily variation in everything from hormone levels, to sleep/wake cycles, feeding behaviour, thermoregulation, to bowel movements and cardiovascular function, among many others.

It is largely due to these predictable circadian rhythms that risk of a myocardial infarction (heart attack) is significantly highest in the morning (by about 40% as compared to other times in the day). Right as we awake, our cardiovascular system is in the most compromised state –systolic blood pressure and heart rate show the largest upward spike in the morning, blood vessels ability to dilate in response to increased blood flow is compromised (relative endothelial dysfunction), blood clots are more likely to form, and the ability to break them up is at its lowest point in the day. Is it any wonder then, that the first snowfall – shoveled early in the morning by people at risk – always leads to a spike in heart attacks?
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Category: News, Obesity Research, Peer Reviewed Research | 4 Comments

Parents play a big role in childhood sedentary time (but blaming them is not the way to go)

Today we have another episode of the Obesity Panacea podcast.  My goal with these podcasts is to interview a different health researcher every month (last month it was Atif Kukaswadia, aka Mr Epidemiology).

This month chat with Dr Valerie Carson.  Val is an absolutely fantastic researcher (she just recently became an assistant professor at the University of Alberta, one of Canada’s top research schools), and is pretty much the go-to person when it comes to sedentary behaviour and physical activity in children.

In this podcast Val explains why physical activity alone isn’t enough for healthy kids (it gives a huge bang for your buck, but you can only fit so much in your day).  She also discusses the delicate balance between educating parents and blaming them (which is obviously counter-productive).  And there are also a few tips for the grad students out there (if you want to be a productive grad student, Val is a very good person to emulate).

In the podcast Val and I discuss a couple of her papers: this one, looking at the way factors in the home influence young children’s screen time, and this one looking at differences in the relationship between self-reported and objectively measured sedentary time and health (as I mention in the podcast, this paper completely scooped one of my own PhD studies… but it all worked out in the end!).

You can find out more on Val’s research on the University of Alberta’s Behavioural Epidemiology Lab website. A reminder that email subscribers can listen to the podcast by visiting the blog.  If you enjoy the podcast, I’d also encourage you to subscribe via itunes.

Travis

Category: Obesity Research, Podcast, Sedentary Behaviour | Comments Off

Eat less meat to reduce your blood pressure

vegetablesA systolic/diastolic blood pressure >140/90 mmHg constitutes a diagnosis of hypertension. Across the blood pressure range from 115/75 to 185/115 mm Hg, every incremental increase of 20 mm Hg in systolic or 10 mm Hg in diastolic blood pressure is associated with more than twice the risk of cardiovascular disease. Conversely, very modest reductions in blood pressure can lead to significant reductions in the risk of cardiovascular events. For example, as highlighted in the HOPE study, a 3 mmHg reduction in systolic blood pressure is associated with a 22% reduction in cardiovascular disease-related death, heart attack, or stroke over 4.5 years.

So how does one go about achieving a reduction in blood pressure?

Most experts suggest blood-pressure reducing medication along with lifestyle modification as the best method. Indeed, numerous studies suggest that modifiable lifestyle  factors, including a diet high in salt, excess body weight, limited physical activity, and alcohol intake, all play a role in increasing the risk of developing hypertension. For some time, it has also been suggested that switching to a vegetarian diet can help reduce the stress on your arteries.

In a recent meta-analysis (study of many studies) published in JAMA Internal Medicine, Yokoyama and colleagues looked at 7 controlled trials and 32 observational studies to examine the influence of a vegetarian versus an omnivorous diet on blood pressure. Their analysis included a whopping total of 21915 subjects!
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Category: News, nutrition, Obesity Research, Peer Reviewed Research | 6 Comments

Motor skills at age 6 are associated with physical activity levels at age 26

Basketball Team conducts free basketball clinic at USAG Brussels - FMWRC - US Army - 100820

Kids who lack motor skills tend to be less physically active than kids who have strong motor skills.  This makes a lot of intuitive sense.  If you have trouble catching and throwing a ball, it’s going to be difficult to play sports like baseball or football.  More importantly, it’s also going to be difficult to throw around a ball with your friends.  Ditto for riding a bike. And skating. (For more on the importance of motor skills, view this previous post, or listen to the below audio interview with motor skills researcher Meghann Lloyd).

If this were just a temporary problem it wouldn’t be a big deal.  The problem is that physical activity levels track over time.  In other words, kids who are inactive become adults who are inactive.  This means that a kid who avoids physical activity due to a lack of motor skills is likely on a trajectory towards a physically inactive adulthood. 

While the above may make intuitive sense, it is really just a hypothesis.  Could childhood motor skills really matter that much?

That’s the question that Meghann Lloyd, Emily Bremer, Mark Tremblay and I recently attempted to answer in a paper published in the journal Adapted Physical Activity Quarterly (available for download here). In the paper, we examined a group of individuals who were first tested in 1991, while they were students in grade 1.
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Category: Peer Reviewed Research, Physical Activity, Sedentary Behaviour | Tagged , , | 7 Comments

Olympic ski jumping competition completed without a single uterus explosion

The female reproductive system (Image via wikipedia)

The female reproductive system (Image via wikipedia)

This week saw the first ever women’s Olympic ski jumping competition in Sochi.  To the shock of almost no one, none of the competitors has since been hospitalized due to an exploding uterus.

Why would this be a concern?  Well, women’s ski jumping was kept out of the Vancouver Olympics (and all previous Olympics) for a variety of reasons.  Mostly it was because the IOC said that there just weren’t enough elite female ski jumpers to justify the competition (although this reason has been debunked). But another reason was a bit more bizarre. You see, the folks who run the International Ski Federation were also worried that ski jumping might cause a woman’s uterus to move and/or fall out and/or burst.

From the Huffington Post:

…as recently as 2005, the president of the International Ski Federation, Gian Franco Kasper, continued to defend the wacky womb-worry rationale, telling NPR: “Don’t forget, it’s like jumping down from, let’s say, about two meters on the ground about a thousand times a year, which seems not to be appropriate for ladies from a medical point of view.”

Nor was this a single off-hand comment.  From Outside Magazine:

The issue came up again as recently as 2010, when Gian-Franco Kasper, president of the International Ski Federation, commented on ESPN’s Outside the Lines that the female uterus might burst during landing from a ski jump…

The fear that sports will somehow damage the female reproductive system are not new – that fear has existed since at least the 1800′s.  The great irony is that, of the two sexes, the female reproductive system is clearly far better protected than the male.  At least the female reproductive system is located inside the body.
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Category: News | 2 Comments

10 Most Annoying People at the Gym

gym personality
In no particular order, here is a list of the most annoying gym goers that I have come across over the years.

1. The Juice Monkey: Juice Monkeys are a staple of most weight rooms, although they will never be spotted near any cardio equipment. Juice Monkeys are characterized by an obvious abuse of steroids and associated extreme anger and hostility (roid rage). They often grunt and scream, but more often than not they yell obscenities. Then can be found standing near their workout area simply swearing for no reason. They often find it necessary to throw their dumbbells around, and make as much noise and disruption as possible. Other sure signs of a Juice Monkey include severe acne, gynecomastia (breast development) and testicular atrophy. Despite their athrophied testes, you should not encroach on their territory as mere eye contact may set these Neanderthals off.

Hint: For the sake of your health, it may be a good idea to drop the juice. For the sake of social integration, drop the bully attitude you perfected in grade school.

2. The Backstage Ass: The Backstage Ass is a relatively new species of gym goer that I only came across recently. This individual is so hardcore that even after they worked out in the appropriate gym space, they just haven’t gotten enough. The obvious solution? Exercise in the change room! That’s right, nothing says you are an intense exerciser more than a set of push ups among other naked men.

Hint: Next time you’re in the locker room feeling like you aren’t quite finished, just make your way back to the gym and finish up there. You can just wear a bandana to let everyone know how intense you are.

3. The American Idol: An increasing number of gym goers do their workouts while listening to their music. Many people swear that their music helps them get in the zone and increase the intensity of their workouts while reducing the perception of effort. All this is copacetic. The problem arises when people confuse the gym with a Karaoke bar. The American Idol has somehow decided their tone-deaf interpretation of Thin Lizzy’s “Boys are Back in Town” should not only be endured but be applauded by their fellow exercisers.

Hint: Stop It! When you get dirty looks from EVERYONE around you, it may be time to step off the stage and re-enter the reality of a gym.

4. The Napoleon Boneparte: Many guys who enter the gym for the first time, particularly those of a slight build, become intimidated by their perceived physical inferiority. The issue with Napoleons is their often dangerous overcompensation. They put more weight on the squat bar than they should, and inevitably end up on the ground, trapped underneath the weight of their stupidity. I can’t tell you how many guys I have rescued from choking themselves out with a barbell while doing bench press and not knowing their limits.

Hint: If you need your friend to hand you the weights because you can’t actually lift them yourself, it’s probably a good indication you should be using less weight. Also, if the only way you can squeeze out a single repetition of a given exercise is with your workout partner lifting 80% of the load – time to downsize Napoleon! If ridicule is your fear, you will attract much more of it by dropping a dumbbell on your head than doing an exercise properly with lighter weight.

5. The Kanye West: Given that the gym attracts those individuals who are concerned about their health and appearance, it is expected that you could bump into a few egomaniacs along the way. How can you spot the Kanye West at your gym? Easy – look for the mirrors! The Kanyes will be found mesmerized by their own reflection as they perform any of the following: roll up their sleeves and flex their biceps, run their hands through their hair, nonchalantly lift their shirts to flex their abs. You may find engaging in conversation with a Kanye West a tad difficult as they will often talk (usually unengaged) to you while continuing to stare at themselves in the mirror.

Hint: Experts agree that the proportion of time at the gym spent posing in front of a mirror is negatively associated with fitness gains, but positively related with looking like a moron.
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Category: Physical Activity | 23 Comments