Tuesday, 28 August 2012

Sleep deprivation and running performance

You know what seems to be the cool thing to do these days?  Running events that are way too long (for me).

I remember when I was in elementary school, the 800m was the longest race ever.  4 loops of the 200m track? Impossible.

Then, in grade 8, the 1500m came along; the ultimate test of endurance (or so I thought).

But boy things have changed.  Athletes are now competing in 100-mile trail races, 8 day stage races (like the ENDURrun) among other similar yet equally punishing events.  When did the marathon all of a sudden become a speed-oriented event?

Needless to say, with the popularity of these ultra events rising, the competition is starting to become much more fierce.  As a result, athletes are looking for new ways to tackle the entire host of new challenges that this type of racing introduces.

Nothing like a 24 hour marathon in Namibia!

Among the most significant of these new challenges: sleep deprivation.

The solution to sleep deprivation is an easy one (sleep more).  But just how much does sleep deprivation impact an athlete over a 24-hour period?  That's what I wanted to start looking at with this blog.


2009 study looked at this issue in an interesting way as they took into account both the perceived challenges of being in sleep debt along with some physiological parameters.

Subjects were forced to go 30 hours without sleep and then complete a treadmill stress test.  They first went for 30 minutes at 60% of their V02max, and then went for 30 minutes as hard as they could.  All of the subjects also completed baseline tests when on normal rest.

The subjects were evaluated using the following parameters: core temperature, skin temperature, heart rate, oxygen uptake, carbon dioxide production, some breathing measurements and rating of perceived exertion.

These are the changes the researchers saw:
  • Less distance was covered after sleep deprivation (by 2.9% on average)
  • Subjects consumed slightly more oxygen during the initial 30 minutes in the sleep deprivation trial
  • There was very little difference in the remaining parameters, including perceived exertion
Practical Applications:

So what does this study show us?  Well, first of all, it points toward the conclusion we all would expect: not sleeping over the course of 30 hours makes you slower than if you were well rested.  

The interesting thing, however, is that there was very little difference in the numerous physiological outcomes that were looked at.  There was a hint of sleep deprivation having a negative impact on cardiovascular physiology (which the authors seem to dispel, I'm not sure why?), but all other measures remained constant.  The authors speculate that the reduction in performance, therefore, was likely due to psychological changes involving how the subjects perceived their level of exertion.

Even though the runners THOUGHT they were going just as hard after 30 hours of not sleeping, they were actually going slower.  Perhaps the lack of sleep lowered their threshold for pain?

Clearly more research is needed.  A next logical step would be to investigate WHY the subjects consumed slightly more oxygen after sleep deprivation despite moving at the same pace.  

That being said, if you are an ultra runner, and you plan on working on limited sleep, this study is nothing but good news for you!  It suggests that your body can keep working while the mind starts to fail.  SO, if you just suck it up, there's a good chance you will be good to go!

Ultra runners (or tired runners)- what are your experiences with running while on no sleep?  Is this study consistent with what you went through? 

Wednesday, 15 August 2012

Silent spinal fractures in Olympic athletes

This month I wrote an article for the New Hamburg Independent looking at one downside to the very strenuous training some Olympic athletes go through.  It's a pretty basic summary of the issue, but a good start nonetheless.  Feel free to e-mail me or comment on the post if you have any questions.  Enjoy!

Silent spinal fractures in Olympic athletes

With the 2012 Olympic Games coming to a close,  it is a great time to be inspired by what the human body can achieve through hard work, discipline and complete dedication.  While this high volume of training helps these athletes perform at an unbelievable level, it also can potentially come with some negative implications.

Believe it or not, some of these athletes may be walking around with training-induced fractures in their spines, and not even know it. 

One of the more impressive events undoubtedly is gymnastics.  The strength and balance put on display by these athletes is astounding.   Yet, have you ever noticed how throughout many of their routines, the athletes rapidly bend backwards throughout their lower back?

While this repeated extension may score them more points, it also increases the odds of developing fractures and forward displacement of bones in their spine.  This condition is called spondolytic spondylolisthesis.

An intact spine showing the area that breaks (LEFT), The initial fracture (MIDDLE), The vertebrae sliding forward (RIGHT)
“A broken back” sounds quite scary, and it is associated with fears of paralysis among other issues.  However, contrary to what you may think, most types of spondylolisthesis are quite common and benign.   In fact, this type of fracture is so stable, many people are completely asymptomatic and have no idea their vertebrae are not intact.

If symptoms do occur, they most commonly include low grade low back pain, a low back that tends to have an accentuated curve into extension, and tight hamstring muscles.  Patients may also experience intermittent electrical shooting pain down the leg relating to pinching the nerve roots as they exit the spinal column. 

So how do gymnasts develop this condition?  It is thought that as these athletes train throughout their younger years, the repeated extension put through their spines causes microscopic stress fractures in a specific part of the vertebrae in their lower back.  These stress fractures, while completely benign individually, start to accumulate, and completely split the vertebrae in half. 

Interestingly, this condition is not exclusive to high-end athletes.   Similar conditions can develop relating to arthritis in older individuals, and even one-time traumatic events such as a bad fall, a tough hit in hockey, or even hitting the bottom of a shallow pool during a dive.  It can even be a congenital issue that you are born with.  So if you suffer from any of the symptoms above, and past treatments for your low back pain have failed, spondylolisthesis may be worth looking into as a possible explanation.

If you do suffer from a spondylolisthesis, and you are one of the individuals who experience associated symptoms, there is plenty you can do to help manage your condition.  In fact, most cases can be managed with some simple manual therapy and specific exercises that will help to target and stabilize the affected vertebrae.

For instance, the gymnasts who induce this injury with their training often have no symptoms at all during their competitive years.  It is only when they retire, and their core musculature starts to detrain that symptoms tend to arise.  Presumably, this is because the stability their muscles once provided is no longer there.

Spondylolisthesis is therefore a condition that more often than not can be managed without surgical interventions.  Like most types of low back pain, core musculature training goes a long way.  So do yourself a favour, use these amazing Olympic athletes as inspiration, and add some back exercises into your daily routine.

Wednesday, 1 August 2012

Does diet composition have an impact on weight loss?

Hello friends!  Time for another enthralling blog post.  Today's topic may or may not hit close to home.  I've been asked enough about weight loss that I figured it is finally time to write about it.

As much as we like to pursue healthy living to help us feel good, prevent disease, improve quality of life and prolong life, often we simply just want to lose some weight.

And as you all know, there are way too many quick fixes.  While we would like to believe there is some magic weight loss formula, the answer, at the end of the day, comes down to calories in and calories out.

However, an area I often get questions about relates to the composition of those calories coming in.  If we are looking at the issue from a pure weight loss standpoint, does it matter what type of calories we consume?  That's what this blog will explore.


A great 2012 study looked at this issue in a very clear way.  Participants were randomized into 4 groups which followed 4 very distinct weight loss diets.  The caloric content was the same, just the composition varied.
  • Two protein amounts were examined (25% of diet vs. 15%)
  • Two fat amounts were examined (40% of diet vs. 20%)
  • 4 carbohydrate amounts were compared (35% up to 65%)
The study examined the following parameters to monitor the progress of the participants:
  • total fat loss
  • lean mass loss
  • abdominal fat loss
  • subcutaneous fat loss (the stuff right under your skin)
  • visceral fat loss (the fat that coats your organs)

This is what they found:

There was NO difference between groups.  

It simply didn't matter what their dietary composition was, it only mattered if they were consuming a calorie-controlled diet.  All participants showed equal fat loss, weight loss and lean mass loss.  All participants lost equal amounts of abdominal fat, subcutaneous fat and visceral fat. 

This study confirms what many others have: weight loss in otherwise healthy individuals comes down to calories in and calories out.

Practical Implication:  

While the answer to weight loss may be as simple as calories in vs. calories out, I am not going to begin to pretend that the issue is that simple in the real world.  When addressing an individual who is trying to pursue weight loss, it is undoubtedly a complex and multifactorial challenge.  Telling someone to eat less and excercise more simply will not work- they already know that!  It's like telling a smoker, "Hey, it's bad for you, so you should quit."

However, what this study does show is that while calories in vs. calories out may not be the answer, it must become the end goal for anybody trying to lose weight.  Whether that means changing social habits, seeking psychological counseling, cutting down on work hours to allow for more exercise; the process will be individualized based on personal needs.  That being said, all of these changes lead to two things: either start burning more calories, or start eating fewer calories.

This study also shows that high protein diets (such as Atkins) really do not have the physiological implications they claim to.  These diets may still work, but most likely because they indirectly result in caloric restriction.  Heck, if you're anything like me, cutting out carbs would result in me consuming about 10 calories/day.  

Also, keep in mind this calorie in vs. calorie out thing does NOT even begin to address the nutritional aspect of what we eat.  For instance, Weight Watchers is actually decently effective in helping people lose weight.  However, the problem I have with it is if you chose to consume empty calories (i.e. 4 beers), then you are going to be forced to skip your nutrient-rich dinner; this is not good!


Weight loss is a very complicated, but at the same time, a very simple issue.  The end goal: reduce caloric intake and increase exercise.  The complicated part is figuring out how you get yourself there.