I speak from 3 years of CrossFit experience. Yes, it has got me in great general fitness. I'm in better over all shape now than I was in High School almost 20 years ago as an athlete. I can do a lot of physical activities well. But I'm not great at anything. That's what CrossFit is all about, GPP (General Physical Preparedness). Perfect by itself for police, fire fighters, soldiers or non-specialist athletic people.

What Brian is doing is taking the Crossfit model and including specific training for swim, bike, run on top of that. It will help the majority of people who do triathlons. I predict it wont make a professional marathon or triathlon specialist better by taking them out of their specialized training. Although I think specialist could benefit from adding some CrossFit to increase strength and expose weaknesses.

The majority of people use triathlons as a form of fitness, they don't race professionally. So the majority of "triathletes" could gain a lot from following Brian's lead, rather than following the LSD model. The same way all the people you see in the gym emulate the routines they read in muscle mags, because that's what the pro bodybuilders do. That is not the best way to become fit. Those who a racing professionally may already be using some forms of weight training which are similar to CrossFit. If they're not, they should be.

Specialist need to specialize, but most of us aren't.