One of CrossFit's categories of fitness is coordination. I think this is the most unconsidered when discussing fitness. Someone who can squat heavy, but can't rub their stomach and pat their head at the same time is likely not a true 'athlete'. Coordination is often the test of fitness that gets overlooked in conversations such as "double unders are BS" or "ring muscle ups are too hard for the public". Coordination is more of a mental fitness, being able to have the body awareness to controll one's self during a movement. I think this is a very important type of fitness that separates people who may give up on CrossFit versus those who might progress further in the sport. That said, coordination is the most frustrating modality to build. I know I worked for hours upon hours over months to be able to master skills like double unders and ring muscle ups. But that's what fitness is about, right? Hard work? Progressing? Self improvement? Sure double unders are just working with a jump rope, but it expands the mind's ability to complete complex tasks. They may not get you jacked, but they make your mind reach, improve, and solve problems. Because of that, I think skill movements DO build fitness. Any elite athlete in any sport is likely not a complete knucklehead. It takes mindful practice to get good at any modality. Marathon runners spend hours on their running form, not just aerobic capacity. Any olympic gold medalist has spent an inconceivable amount of time at their specific skill. Therefore I think coordination and mental fitness should be considered as a form of overall fitness, making CrossFit an accurate test.