If you haven’t ever read the classic article titled “What Is Fitness” from the October 2002 issue of the CrossFit Journal, we highly recommend you do so. This premise of this post is to break down a small portion of that article for quick overview and understanding. We believe educating our members as much as they are willing to learn is important and therefore, the purpose of this post is to do just that by focusing on the effectiveness of CrossFit training.

It’s clear that CrossFit has an evangelizing effect on many of its athletes and rightfully so. However, few know the science behind the effectiveness of the programming that they are training with.

The well known “met-con” or metabolic conditioning is a staple in CrossFit training but what many CrossFit athletes don’t know is that there are really three metabolic pathways that make up many of these testing workouts. These three are known as the phosphagen, glycolytic, and oxidative pathways. The phosphagen pathway entails activity that takes 10-30 seconds of work, the glycolytic pathway consists of activity that lasts 30 seconds – 2 minutes of work, and oxidative 2 minutes and beyond. These pathways apply to all activity in everyday life.

If you look at many sports, you can can actually categorize which metabolic pathway they are primarily using in only one or two areas. For example, football makes high use of the phosphagen and glycolytic pathways while a marathon runner is operating primarily in the oxidative pathway. In other words many sports and forms of training are either anaerobic (phosphagen and glycolytic) or aerobic (oxidative only).

What makes CrossFit so effective compared to other sports and forms of physical training is the balance among all three of these pathways. When doing a well programmed CrossFit workout, many athletes understand they are doing a combination of movements from gymnastics to weight training, but don’t realize they are actually making use of all three of these pathways which is what’s really helping them get the results they are receiving. In addition, when a workout is requiring an athlete to push to a certain point and then causing them to rest you can observe this balance in others or yourself when training.

This balance is what helps CrossFit make fast athletes strong without losing speed and strong athletes fast without losing strength. It is also this ability to expand across a broad range of modal domains that make it unlike typical interval training. By not specializing in one area of fitness, but mixing several areas together with varying degrees of reps, rest, and time, CrossFit is able to produce the results that it does and therefore, is why CrossFit works.