Dan is an Athletic Evolution athlete (featured in the Athlete Review a few posts back). He recently wrote an article, which I feel compelled to share. So, here goes:
“‘Overextrapolation’ and its effects on CrossFit
With a growing number of people around the globe becoming increasingly aware and/or involved with crossfit and the claims of its “evidence-based improvements in fitness”, a growing number of the community are taking it upon themselves to search out more scientific research to support their new found lifestyle.
Now, don’t get me wrong, I am all for people finding a peer-reviewed research article on an area that particularly interests them in order to further their knowledge. What I have a problem with however, is the complete misinterpretation/overextrapolation of lab bench research data by the media which is then re-posted and circulated around Facebook as if it were hard fact by keen crossfitters looking for some form of scientific justification for a life style choice they have made. Overextrapolation is a term used to define sweeping generalisations that are made about a piece of research that was conducted on a very specific sample population. I shall draw your attention to just a few articles that I have noticed on my ‘news feed’ this week and will explain how the media have completely misunderstood the original article thus leading to a complete overextrapolation of the data and how in turn this effects the crossfit community.
Firstly, I was faced with a headline that read “Sugar can make you dumb”. That is a very bold claim and one that I was eager to investigate. The study compared two groups of lab rats, one consuming omega-3 and docosahexaenoic acid (DHA) suggesting that these are “brain-boosting” (something which in itself is unproven in the scientific literature) supplements alongside a high-fructose corn syrup and the other group of rats consuming just the syrup. The study found that after substituting the high-fructose corn syrup with drinking water for 6 weeks that the group without the “brain-boosting” supplements forgot their way around a maze in comparison to the other group (it should be noted that the other group also didn’t make it around the maze but got further than the syrup-only group).
The trial used two groups of rats, one with syrup and “brain-boosting” supplements and the other with just syrup, however, there was an absence of a “control” group (a group of rats who continue to drink normal drinking water), this allows comparisons to be made between all groups which may help the authors and the readers make judgments as to what is causing the “dumbness”. Without this group it is possible to reason that many other factors may be causing the memory loss of the animals such as the amount of time spent away from learning the maze, for example. This critique of the study is all well and good but let us not forget that it is the overextrapolation by the media and the re-posts that we have an issue with here. This study considered genetically engineered lab rats as subjects, NOT people; it examined a massive dose (6 weeks) of high-fructose corn syrup, something which would not happen in a real-life situation and it tested a rats ability to remember its way around a maze, NOT a human’s ability to perform a standardised test, for example. What I am trying to say is that the media headline should have read something like “Large doses of sugar caused a sample of rats to forget its way around a maze”. It is foolish and dangerous to assume that this may have similar effects in humans without further research and to understand that this misunderstanding can have a negative effect on the crossfit community.
Crossfit claims to be an “evidence-based” exercise programme that provides “measureable” improvements in fitness yet there is a distinct lack of scientific literature available to the community regarding this. The crossfit journal provides vast quantities of anecdotal evidence but very little in the way of peer-reviewed journal articles, is this because it doesn’t exist or because we are being withheld the information? I believe that this lack of scientific evidence (or lack of access to the evidence) regarding crossfit and other lifestyle choices surrounding crossfit such as Paleo is what is causing crossfitters to be sucked in to believing these overextrapolated news headlines as they want evidence to help justify their new found love/obsession to the “haterz”. There are a lot of misleading headlines in the news and technical jargon is everywhere, for example, I recently read one news article online which described the results from a “clinical” study looking at how a combination of soy and animal protein isolates was the most effective method for increasing muscle repair post-workout. However, this so called “clinical” study examined 19 males, hardly the number of participants you’d expect from a clinical study (which would be in the hundreds/thousands). In this small sample a difference in the combinations of protein and soy may have been noted but this is a very small scale and limited population size, for example, would these effects have been significantly different if there were more subjects, or if the sample group consisted of females or a mixture of females and males? These news articles could potentially lead to misguided advice being given to crossfitters by their coaches and could ultimately impact negatively on their health.
My advice to crossfitters looking for research regarding the training methods and nutritional advice seen in the crossfit programme is to be skeptical of these overextrapolated headlines and investigate them further. It never really is as simple as one cause leading to one effect in the body, after all, we are complex chemical factories and what may appear to be a causal relationship at first glance may be far more intricate on closer inspection. If you want to search for scientific literature then I’d recommend using this website http://www.ncbi.nlm.nih.gov/pubmed/ . It provides millions of articles on biomedical literature that will really aid in developing your understanding of key questions you have such as “Is squatting to full depth beneficial and why?”, “What are the best nutritional strategies for optimal performance and why?” and “How effective is high-intensity training at improving aerobic fitness and why?”. By sourcing these peer-reviewed journal articles and re-posting these to Facebook you are going to help to shape a community that is logical, rational and up to date on the latest scientific research in a particular area. If you are a coach this will equip you with more knowledge with regards to biomechanics, nutrition and physiology and will ultimately increase the value of the product you are offering. Also, if you are an avid crossfitter you will be able to justify your training choices to your peers and will also increase your knowledge with regards to training and nutrition.”
Thoughts and comments, please?