As a trainer I really respect and support exercise programs that have an honest intention of helping others  and promote a healthier lifestyles. I don't dislike weightlifting, CROSSFIT, or the like. I do understand that there is a much better, safer, and more beneficial way to train people specifically for athletic performance.

CROSSFIT admittedly states that it is not adequate for sport training in one of their oldest and most famous quotes:

“Our specialty is not specializing. Combat, survival, many sports, and life reward this kind of fitness and, on average, punish the specialist.”   – Greg Glassman, Founder of CrossFit

All athletes are specialists of their sport and require a specialized set of skills for that particular sport. The verbiage used here is great marketing, but an example of the profound ignorance of inadequate trainers

Traditional weightlifting, powertlifting, olympic weightlifting, CROSSFIT, bodybuilding, etc. are not adequate means for training athletes, law enforcement, or military personnel who require a specialized set of attributes for their performance. These methods actually destroy muscular equilibrium and deter peak athletic performance and speed over a prolonged period of time with an increasing load. (Korobkov, 1953; Monogarov ,1958)

As a trainer myself, and after working with and learning from the some best in the business, I feel more strongly about the need to speak out about High School and Collegiate programs and others like CROSSFIT, Yoga Studios, and other workout facilities/programs who programs consist primarily of inadequate methods of training for athletes. Many programs precribe Olympic weightlifting for athletes without fixing weak hips, backs,feet, etc first.

In their highlights and videos, I see on a regular basis girls with weak hips and feet performing plyometrics, not to mention poor running mechanics. These images haunt me because of the risk of injury they carry, yet this is prevalent in schools and gyms around the country.

"Functional" training exercises are designed to improve basic functions, however athletes must surpass the basic necessities of "functional". "Functional" movements such as the squat and deadlift require the athlete to load the weight on the heel while performing these lifts.

In what sport are athletes running or generating any force through their heels? or performing these movements in any sport other than Olympic Weightlifiting? None. But yet these lifts are used to train athletes to help running and jumping?

During sports nearly all movement is done with the load of your body placed on the forefoot. Needless to say if the forefoot is not trained to transfer the force that the legs have been trained to produce via squatting/deadlifting etc., how is it then being applied to a sport? It's not. It's this improper training with these type of lifts that increases the risk of ACL tears, hamstring and quad injuries as well as lower back and ankle problems.

Before reading further please understand that the way you workout, or "TRAIN" your body to move in the gym is the way you are TRAINING it to move in sport, literally. Think of your last workout, were the repetitions tense and slow? did your performance end on a slower, sloppy note, or did you go to total exhaustion?

Should you continuously replicate this pattern of performance and expect it to make you better?

When planning your workout you must keep the question in mind, what movements will help improve the movements needed for my sport?

As the weight you lift increases your speed and accuracy decreases, plain and simple. This is proven throughout science. (Korbkov,1953; Vasiliev, 1954; Gerasimov,Yakhontov, 1954; Zimkin, 1956, Agdgomelashvili, 1964; Butenko,1967)

Aside from these points listed above I have not witnessed CROSSFIT address lateral movement, rotational force, muscles of the spine and lower abdominal cavity, hip abduction/adduction, proper glute ham contraction, injury remediation, involuntary reflex, etc..

Aren't these attributes needed for athletes, law enforcement, military elite, etc..?

Without a method of testing for imbalances and weakness they will almost always produce further injury and imbalance. These workouts are prescribed in a generic format, which neglects the needs of INDIVIDUALS who all have different weaknesses requiring different training priorities. Many of the workouts are performed with a prolonged race against the clock, pushing the body into a state of exhaustion at which point focus, coordination, timing, form, all decay. Resulting in performance that has slipped well below their Peak. 

Out of 4,400 affiliated Crossfit gym I cannot name 1 elite professional athlete they have produced.

OLYMPIC WEIGHTLIFTING IS A HIGHLY TECHNICAL SPORT.

Having a football player perform Olympic lifts is the equivalent of having an Olympic weightlifter play football to get better at Olympic lifting.

You wouldn't train a baseball player the same way you would train a firefighter would you? or a football player the same way you would train a swimmer?

So how do generic functional programs address the needs of athletes? They don't.

Do these type of workouts make you mentally tough, and able to push through pain and misery? In my opinion,  yes they do. However there are better ways of doing it than beating yourself into submission. Chances are if your body is being pushed into this state of pain and misery in sport, fighting, law enforcement then you are already on the losing end. Our goal is to see to it that you never reach that point  of falling behind to begin with. We focus on PEAK PERFORMANCE, not deteriorating performance.

Take a look at nature..

If you look at jungle cats, they are arguably the most athletic of all mammals. They can run fast, jump high, change directions quickly, balance, react instantly, have a incredible strength to bodyweight ratio ..yet they lift no weights at all. Compare that to a Horse pulling a plow, or a rhinocerous. Which one is a better athlete? these animals were created by the stimuli in their environment and evolved over time to become what they are as the end result. When you think of your training program you must always consider what will happen if you continually progress down the road you have chosen. Will you end up like a jungle cat ready to sprint, jump, balance, fight? Or will you end up like a strongman who can barely wrap his arms around his own chest, stiff, with an aching back or hamstring issue. In the wild those attributes will get you killed. Those are the end results.

The Muscle is part of a protective/adaptive component of the musculoskeletal system which is controlled entirely by the nervous system. The human muscle is designed to produce on average 40% (varies between upper and lower body) less force concentrically than it can resist eccentrically, multiple repetitions of the same weight throws this ratio completely out of balance.

The human muscle produces the greatest amount of force by RELEASING ELASTIC ENERGY that is stored in the various MUSCULOTENDINOUS UNITS. Think of jump roping, once you start jumping it's easier to keep going as opposed to jumping once, then stopping for 3 seconds then repeating. This is because the STORED ELASTIC energy in your feet, achilles, legs, etc. is greatly contributing to the work, rather than relying on the muscle alone.

How is this ELASTIC ENERGY STORED?

This is important to know.

The STRETCH SHORTENING CYCLE.
This is when an eccentric load creates a forceful stretch of tendons and ligaments, which then use that stretch to their benefit by RELEASING THE STORED ENERGY created by the stretch and immediately contracting the muscle, producing a more forceful and faster contraction. This is why Plyometrics have been proven to develop explosive strength faster and to a greater degree than any other type of resistance training method.

Perhaps this example will help clarify:

Think of jumping on a trampoline except that, the trampoline is the muscle and you are the load being imposed on the muscle. The higher you jump (the more eccentric force you will impose) on the trampoline, the higher the trampoline will propel you because of its stored energy.

Now to correlate with the above statement, imagine the trampoline as the muscle, and the springs around the trampoline as the tendons and ligaments, together they form the MUSCULOTENDINOUS UNIT.

What would happen if you made the trampoline thicker and heavier than it was meant to be without putting stronger springs on there? It's not going to throw you off as high and it's probably going to tear somewhere, somethings gonna give...

We train the muscles, tendons, and ligaments as a whole so that it maintains equilibrium and elasticity. The result is that we have far less injuries, develop more force as well as more grace and fluidity of movement.

Weight training that focuses on HYPERTROPHY increases the muscle cell without regard to the musculotendon unit.

If a trainer knows how to read a bar graph then it's easy to understand, as the LENGTH-TENSION RELATIONSHIP and FORCE-VELOCITY RELATIONSHIP clearly explain the science proving how these types of training listed in the first paragraph destroy muscular equilibrium.

Weightlifting does not challenge the muscles and tendons in various joint angles adequately throughout the range of motion, resulting in an unbalanced muscle.

 EX: When performing a squat or bench press, the load feels much heavier at the bottom of the movement as opposed to the top of the movement where it feels easiest. This is because as the joint angle increases the muscle produces more force, simple biomechanics. With that in mind if 100 pounds is challenging at the bottom but easy at the top, how is this producing equilibrium in the muscle, or challeging the muscle to its potential accurately? It's not. It is however training the muscle to become slow in the smaller joint angle, faster in the larger joint angle, creating crossbridges in a pattern that is optimal for developing hypertrophy but not optimal for muscular equilibrium, strong tendons and ligaments, healthy joints, and a balanced body for sports performance.

It's really pretty basic to be honest, you can ask any physiology professor to explain it to you. The heavier the weight you lift, the slower the contraction, the less precision you have with your movement, the less control and relaxation you have with your body, the shorter your muscles become, and the slower you become.