Crossfit has done great things for the fitness community. Crossfit spread barbell training to the masses; it's no longer just a niche community of gym rats and powerlifters. Crossfit espoused the concept that human bodies are for something more than just being looked at. This concept is especially important for women. Unfortunately, Crossfit is built on a system that rewards poor form, short term benefits, and selects exercises that are suboptimal for fitness. The quality control on Crossfit coaches has also created a lack of reliability when going to an affiliate; you might get a good coach, but more likely, you'll get an idiot.
Short term incentives and Programming
Crossfits run WODs (workout of the day) which, in general, are timed workouts. Crossfitters are also highly competitive and this is encouraged by the organization. During the timed workouts, Crossfitters are constantly racing against each other to be the first to finish. Theoretically, this could be done in a healthy way, but that's the outlier rather than the commonplace practice. What's common is exercises that have atrocious technique and cut off range of motion and trainees pushing themselves far harder than they should be. I've seen this many times. The most notable example was when I did Murph for the first time.
Murph is a timed workout with the following exercises:
1 mile run
100 pull ups
1 mile run
You can do these in any order. For example, run 200m, 10 pull ups, 5 pushups, 5 pull ups, 50 squats, 10 pull ups, run 500m, etc.
Everyone started with solid form. Soon, however, many trainees did partial range of motion pull ups and squats and nose to ground pushups. As the workout progressed further, their form deteriorated more and more until they were barely moving through any range of motion. The worst part was when a man who had never done Crossfit and had not exercised since he was in college came in with a friend and asked to join. The owner said "Sure. Glad to have you", and that was basically it. He finished last after having thrown up twice about three quarters of the way through the WOD. Everyone encouraged him to keep going and finish including the owner and coaches. This is an awful idea. When you throw up, you're done for the day. Cool down, drink some water, and rest. Not only did the owner not even bother to scale his workout (maybe do a third of the reps), but he and his coaches encouraged him into continuing even after he threw up.
Crossfit places short term validation over long term progress, and this is an awful way to get fit. Workouts should cause stress that can be recovered from so that adaptation and the consequent goals can be achieved. Crossfit programming is not done with this in mind. I have never met a Crossfitter that can clean more than 315lb. I know there are Crossfitters that can do it, because I've seen it on youtube, but I can guarantee they aren't doing the WODs that Crossfit.com posts, because complex movements must be practiced frequently to maintain technique and the Crossfit.com WODs include cleans maybe once or twice a month.
The other programming issue is that highly complex movements (cleans and snatches) are done for high reps. The problem is that these are highly technique dependent movements, high reps cause fatigue, and fatigue disrupts good technique. The more technique dependent the movement, the worse it is for high rep training. Because of this, the prowler is an excellent tool for conditioning, because it requires almost no coaching or technique adjustments; you just push it and don't need to think about much.
The largest problem with Crossfit gyms, specifically, is the lack of quality control in their affiliates. If you want to open a Crossfit gym, you can sign up for a Level 1 cert online, pay $1000, spend a weekend at a Crossfit gym learning how to do box jumps and cleans, and pass a multiple choice test. In the eyes of Crossfit HQ, you are then qualified to coach trainees in complex movements where injury is a serious possibility. 16 hours, and you're good to go.
Now that said, I have been to Crossfit gyms with phenomenal coaches who know a lot about strength and conditioning. However, that is not the usual case. The usual case is an owner that is highly passionate about his business and coaches that have no idea how to do basic coaching functions: designing an exercise or program for a deliberate goal for their clients, cueing a trainee to get them to do an exercise properly, and actually listening to the trainee about what issues and goals the trainee has.
The problem with this is that, when you go to a Crossfit gym, unless you're already a strength coach, you don't know what you're getting. You could be getting an experienced, educated coach that will help you or you could get a 20 year old who's majoring in exercise science and thought it would be fun to get his Crossfit Level 1 last weekend.
There are several downfalls of Crossfit that can be learned from. Exercises must be practiced consistently to maintain technique. Training is done for a specific long term goal, not just so you can crush Justin at the WOD. Quality control on coaches for any organization should be well managed, and consequently, if you know an organization doesn't have decent quality control on their coaches, understand you probably won't get an experienced coach. Finally, highly technique dependent movements should not be done for high reps. I hope anyone thinking about doing Crossfit will consider these undeniable assertions and save their money for high quality coaches and programs that will actually work to achieve their goals.