I would have't to agree with Lauren's comments...
I've never set foot in a crossfit or gym jones set-up, watched some videos though, i feel the term "functional training" is very miss leading these days. That said, i do have many years of experience in High Intensity Training, am a advocate of training to failure, however as i get older (now 35) i'm now becoming more concerned with the damage / wear and tear element associated with exercise, there are ways and means of developing strength and size in the body, while at the same time, minimizing the potential for of damage.
Am not just talking about using bad form or overtraining here (which are negative factors in themselves), am talking about years of moving through positions of disadvantaged leverage, and high impact training. These are elements i see with Crossfit and other such protocols, their effective protocols no doubt, however there are HUGE wear and tear issues associated with such protocol's, issues that will return to bite the practitioner on the ass in years to come.
A great example was when a cardiologist by the Name of Dr Cooper published a best selling book called "Aerobic's" back in the 60's, he advocated that we should engage in lots of steady state activities such as running etc. Low and behold, in the years to come, physiotherapists were inundated like never before with thousands upon thousands of people that had taken the advice of that book. Cooper did not become known as the man who saved America's hearts, but rather, daubed - the man that destroyed America's knee's.
To learn more about this i strongly recommend you listen to some John Littles work, John is the owner of Nautilus North Training facility in Canada, were he has overseen 60,000+ H.I.T workouts and has also conducted some very interesting independent research of his own. He is the founder of Max Contraction Training, the Max Pyramid Protocol, and co-author of the world wide best selling book body by science (as well as 30 other books). He work and was close friends with pioneers of H.I.T Mike Mentzer and Arthur Jones. The interview's below are two of the best i've heard in the last 22 years.
In these interview's, John also talks about the fraud that goes on in exercise today, he talks about why he left a well paid job as an editor at flex magazine due to the corruption in what they were selling....makes for very interesting listening. http://www.highintensitynation.com/2011 ... hn-little/http://www.lifeintherough.com/2008/07/3 ... interview/