-by Coach Rachel Binette

CrossFit works. All around the world, people are losing weight, getting stronger, and living better lives because of CrossFit.

But how does CrossFit work? What makes it special compared to other fitness regimens?

Here is the definition of CrossFit:

Constantly Varied
High Intensity
Functional Movements

CrossFit employs constant variance of functional movements at high intensity to improve fitness. Each of these components are critical to the definition of CrossFit. If we take any one of them away, we lose a potent part of what achieves results for CrossFitters.

We have been taught that specialization is the best way to achieve a high level of fitness. That is true when we are competitive in a sport--if we want to become a gold medal-winning Olympic swimmer, we must train swimming. However, training for a specific sport only improves our capacity for playing that sport. If we run for 3 miles per day, we become very good at running 3 miles per day, and that’s it.

We improve more when we apply many stimuli to our training.

In these two pictures, we have the input of “stimulus,” the workouts we perform, and we have the output of “adaptation,” which is what our body is doing when it improves in fitness. The bottom picture is the ideal–more stimuli leads to more adaptation. Variety is our friend, and “routine is the enemy.” Being stronger is good, being faster is good. Being stronger and faster is best.

How does this translate to our training? Programming. CrossFit programming is designed to maintain a variety of stimuli for increased adaptation over time. We see long workouts, short workouts, workouts with a variety of movements, each of them designed to train a facet of athleticism that transfers to increased adaptation. What are the different types of stimuli and how can we, as athletes, ensure that we’re receiving a constantly varied training regimen? By training the three metabolic pathways and by training every variety of functional movement that we can.

The Metabolic Pathways

Our bodies are capable of exerting effort over many different time domains. We can perform a 1RM back squat. We can do “Grace.” We can run a marathon. These tasks use different metabolic pathways to exert effort. Each metabolic pathway uses different sources of energy to fuel our activity.

We’ve all heard of aerobic and anaerobic training: aerobic training uses oxygen for fuel, and anaerobic training doesn’t use oxygen. Anaerobic sources of energy are ATP for the Creatine-Phosphate System, and stored carbohydrates, or muscle glycogen, for Glycolysis. The Creatine-Phosphate System is our top speed–it’s what we use when we are sprinting away from a bear, running for our lives. As we work at max effort, our ATP runs out after about 10-12 seconds. Then our body begins using muscle glycogen for energy, running out after between 90 seconds and two minutes of work. Glycolysis is another energy system for moderate to high speed--sprinting 400m for instance. After we’ve run out of muscle glycogen, our body can only use the oxygen we are breathing in to continue to fuel our effort. Once we’ve started to use oxygen to fuel our effort, we are moving more slowly. Athletes with superb stamina replenish their energy stores better and faster. Through recovery, our ATP and muscle glycogen replenish, and then we’re able to move quickly again.

CrossFitters train all 3 of the metabolic pathways. Deadlifting heavy on Friday to train our Creatine-Phosphate System, then performing a partner workout that uses our Glycolytic System on Saturday, and following up on Monday with a 30 minute EMOM, we have allowed our metabolic pathways to develop and support one another. This means that some days, our workouts must be under ten minutes long. Those five to ten minutes, when performed with high intensity (either heavier load, longer distance, or more repetitions within that time), will be more than enough to force adaptation. Training our anaerobic capacity has been proven to support the development of aerobic capacity.

Monostructural, Gymnastics, and Weightlifting

The movements we perform are probably the easiest form of variety to spot in programming. Here are some quick examples of each of these “modalities” for your reference:

Monostructural: running, biking, swimming, rowing, jump roping.

Gymnastics: pull-ups, push ups, dips, handstands, toes-to-bar.

Weightlifting: deadlifts, snatches, back squats, kettlebell swings.

The variety of movements in CrossFit is astounding, and is a large part of what makes it such a special training regimen. In avoiding specialization, our muscle recruitment is more nuanced than that of the specialist. Through muscular balance, by pulling, pushing, holding, running, jumping, squatting, rotating, stabilizing, flexing, extending, and on and on, our adaptation supports more of what we may want to do. Invited to go rock climbing one weekend? You’ll be prepared. Need to help an elderly relative move furniture? You’ll have it covered. A marathon runner’s training prepares them for running marathons. A CrossFitter’s training prepares them for everything.

A quick note on linear periodization:

A key component of the definition of CrossFit is constantly varied. Linear periodization (like the Wendler) is a popular method for building strength, and it is easy to see why: over the course of 8-12 weeks, lifters who employ this program do improve their strength benchmarks. What CrossFit recognizes, however, is that any linear program, one that does not employ constant variety, leads to plateaus in that specialized focus--this is known as accommodation. We stop improving when we do the same things over and over. (And isn’t that the truth for every part of our lives?) In addition, when the program ends, the adaptation is no longer needed, and so the strength that was gained is lost again. In order to facilitate adaptation, we employ variety.

Loads, Holds, Carries

In weightlifting and gymnastics, there are 3 more modalities to consider in training: loads, holds, and carries.

Load: a moving weight, whether it is bodyweight, a barbell, a kettlebell, or a D-Ball. Most CrossFit training incorporates loads through prescribed weights and bodyweight movements.

Hold: a static, or unmoving, position under tension. Examples include a handstand hold, the pause in a pause squat, and hanging from a pull-up bar.

Carry: a weight that is carried; yoke carries, sandbag runs, and farmer’s or suitcase walks are some examples.

Each of these modalities contain their own value in training muscle recruitment. A load, like a squat, is an everyday movement that staves off decrepitude. When we can get up off of the floor after falling at the age of 70, we have trained well. A weighted or gymnastics hold improves our muscular endurance and stability. As fatigue sets in, other muscle fibers take over. In weighted carries, we learn to use our midline more effectively to stabilize our spine. A strong midline supports every part of our lives, from deadlifting 500lbs safely to picking up our grandchildren.

How does constantly varied training impact us as athletes?

When we train consistently, we have a greater chance of receiving a constantly varied training regimen, and therefore a greater chance of seeing the results that we seek: improved health biomarkers like blood pressure and resting heart rate, athleticism that supports our lifestyles, and improved body composition.

In evaluating the training we receive, we look at time domain to see the metabolic pathways we are training (with the understanding that intensity is a critical factor--ATP runs out at 10 seconds of max effort) and we look at the variety of movements that support improving our athleticism (squats and deadlifts for lifetime functionality, Olympic weightlifting for developing power, and monostructural work for advancing our cardiovascular health, to name just a few). Great CrossFit programming is varied CrossFit programming, so great CrossFit training contains as many time and movement modalities as creativity allows. While the programmer provides the variation, it is up to us, the athletes, to ensure that we are undiscriminating when it comes to our training. Avoiding short workouts ensures that the two anaerobic metabolic pathways will remain a weakness. Avoiding a movement that challenges our egos neglects our capacity for improvement.

Constantly varied training gives us the biggest bang for our buck. In the next installment of this series, we’ll talk about High Intensity--why it is so important and how and when to use it.

Why Variety is Key to Your Success