ICPAPH 2010 - A Recap

The Toronto Charter for Physical Activity

As many of you know, I spent last week attending the 3rd International Congress on Physical Activity and Public.  It. Was. Awesome!  I've been to 5-6 conferences since I started grad school in 2006, and they've all been good experiences, but this one was by far the best.  And of the more seasoned researchers that I've spoken to, they all seem to rank it among the best they've attended as well.  Unfortunately I wasn't able to liveblog the conference as I'd hoped (the wifi was pricier than I'd expected) so I thought I'd recap my experiences here on the blog instead.  Here are the things that stuck out for me - if you attended the conference yourself, feel free to add your thoughts as well!

Sedentary Physiology Takes Center Stage

The most exciting aspect of the conference for me personally was the extreme amount of attention paid to the importance of sedentary behaviour.  As I've blogged before, recent evidence suggests that sedentary behaviour (e.g. sitting) is associated with increased health risk independent of physical activity levels.  For example, one recent study has suggested that no matter how much physical activity you perform, individuals who spend most of their day sitting are at dramatically increased risk of death over a 12-year period (details here).  There were several symposiums and 2 plenaries on the topic of sedentary behaviour, with the world's top sedentary physiologists including Neville Owen, David Dunstan, and Genevieve Healy from Australia, and Marc Hamilton from the US.  And the highlight of the conference was undoubtedly James Levine, who coined the term NEAT (Non Exercise Activity Thermogenesis) and who delivered the final plenary during the closing banquet. There were several presentations building on past work, suggesting that even just a few hours of sitting can result in serious metabolic dysfunction, and I was fortunate to be able to chat with several of the researchers whose work we have previously discussed here on Obesity Panacea, which was a real (nerdy) thrill for me.  But even among those who are not steeped in the field of sedentary physiology, it was clear that physical activity researchers are starting to take sedentary behaviour very seriously, and the amount of research in this area seems to be increasing exponentially.

Energy Balance & Body Weight

One theme that popped up repeatedly at the conference was the issue of
exercise/energy balance and body weight.  The conference began on
Wednesday afternoon with a session on the topic chaired by Dr Steve
Blair.  The first speaker was Dr John Blundell of Leeds University.  Dr
Blundell discussed research from this recent study
published in the International Journal of Obesity which demonstrates
the huge variation in weight loss when individuals are exposed to an
exercise program (see Figure 1 on page 27).  For example, in 30 subjects
exposed to 12 weeks of aerobic exercise, the average weight loss was
3.7 kilograms.  However, some individuals lost as much as 14 kg, while 4
participants actually gained weight.  Dr Blundell used this
evidence and other similar studies to suggest that the "average" weight
loss in response to exercise is often meaningless, given such extreme
variation.  However, his data also suggested that among those who lost
little weight, and even among those who gained weight, there was still a
consistent reduction in fat mass, waist circumference, and an
improvement in other health indicators (the increased weight was largely
due to increased muscle mass).   In another session on a similar topic,
Dr Tim Church suggested that reductions in workplace physical activity
levels accurately predict the increase in obesity over the past 60
years.  And at the closing banquet, Dr Levine discussed his own work
which has shown that
individuals vary widely in their ability to prevent weight-gain through
increased physical activity when forced to consume 1000 extra calories
per day.

I think that these issues of responders vs non-responders may also
explain the differences of opinion that many people have on the role of
exercise in weight management.  Looking at this study  by
John Blundell or this
one by Chris Riddoch, it's difficult to argue that exercise plays no
role whatsoever in weight management.  However, I can see why our
colleagues in primary care would disagree, since they would be most
likely to encounter the "non-responders" that Dr Blundell referenced in
his speech - why would a "responder" continue seeking treatment?  I'm
not saying this explains everything, but I think it can help explain why
the evidence on this topic is so mixed, making it very difficult to
come to any definite conclusions (or allowing people to come to very
different conclusions).

This is an issue that I want to come back to in the future, but
suffice it to say that the issue of exercise and body weight is a
complicated one.  Exercise can clearly reduce body weight in the
short-term, as many studies by my MSc supervisor Bob Ross have shown
time and again.  However, there also appear to be consistent findings
that some people lose far more weight than others, and in general I
think we can all agree that focusing solely on exercise is a poor plan
if you're goal is long-term weight loss.  Similarly, exercise may not
completely prevent weight gain when exposed to an excess of calories,
although it can clearly help, as
we've discussed in the past.  As Dr Blundell summed it up, the
effect of exercise on body weight is not spectacular, but the findings
are generally positive.  By the end of the conference I was
personally starting to tire of this whole debate, and I agree
wholeheartedly with Dr Blundell that we need to move away from such a
narrow focus on body weight given the wealth of evidence showing the exercise is associated with numerous health benefits regardless of what is happening with body weight. 

Public-Private Partnerships

As many people know, this recent conference was sponsored by
Coca-Cola.  This led to some excitement on the opening night of the
conference, when George Davey Smith criticized the food and beverage
industry, claiming that they have misrepresented the association between
soft drink consumption and health.  I wasn't able to attend the opening
plenary myself, but the PLoS Speaking of Medicine blog has written
their account of Dr Smith's speech here. 
This is obviously another tricky issue - a soft-drink company
sponsoring a health conference - made more complicated by the fact that
the conference would likely have been almost impossible without their
financial support.  Is it better to have no conference at all, or a
conference sponsored by a company that sells sugar-laden beverages?  Is
it better to engage the industry, or avoid them completely?  These
questions are all well above my pay scale, but I heard a lot of
delegates discussing them throughout the conference, which seems like a
good place to start.

The Toronto Charter on Physical Activity

I discussed the Charter in my
post last week leading up the conference, and it wound up being a
highlight for me personally, and many of the other delegates that I've
spoken to.   The final draft of the Charter is now available here.  In short, the Charter is a tool which
can be used to advocate for increased physical activity as a means of
increasing the health and productivity of society.  The Charter has had
input from more than 400 individuals from over 50 countries, and is
likely to be a watershed document in the promotion of physical activity
(it was also signed by more than 500 delegates, including myself!).  It
includes concrete suggestions on ways to advocate for increased physical
activity at all levels of society.  If you work in any field remotely
related to physical activity (public health, sport and rec, education,
city planning, you name it!) then this document can help you advocate
for increased physical activity.  The authors of the Charter have urged
everyone to share 5 copies of the Charter with their friends and/or
co-workers, and to ask them to do the same.  I've just shared it with
all of you, now go share it with the world! And to see what Speaking of
Medicine is saying about the Charter, click here.

Final Thoughts

That pretty much sums up my experience from the past week!  I realize
that I didn't even mention my poster, which went well but wasn't quite
as exciting as some other parts of the conference (which is to be
expected from a poster presentation).  I should mention that I was also
able to meet quite a few readers of the blog, which is exciting - I'm
still amazed that we have any readers aside from Peter and myself!.

I learned about a lot of cool stuff at this conference, and I'm
hoping to expand on the issues that I've discussed above in future
posts.  ICPAPH was a terrific experience, and I'd urge everyone to save
up for the next Congress which will take place in Sydney, Australia in
the fall of 2012 [let me know if anyone has a spare couch where a grad
student/blogger could crash for a couple nights... :) ].  The powerpoint
slides from all of the plenary sessions, as well as the final draft of
the Charter should be available on the conference website in the near
future, and I'll put up a new link as soon as that happens.

What were other peoples' experience of the conference?

Travis