In this day and age, it is difficult if not borderline impossible to live without stress. We’re constantly connected through social media, we overschedule our days (and nights), we live in a crowded, polluted, noisy world … stress is, according to one report, “an inevitable part of a busy, modern life.”
And that’s just the MENTAL side of things.
The truth is, while having kids of dating age or trying to get past rubberneckers when you’re late for work are stressful on our bodies, physical stressors are a regular part of our daily routines, as well. In fact, we’re almost constantly experiencing some sort of physical stress … and we’re lucky that our bodies are designed to adapt to it.
CrossFit is what we call an intentional stressor. Exercise has been likened to “… a reset button for stress,” but that is more the psychological side of things. CrossFit is designed to cause physical stress to the body, meaning the body must adapt; the difference is that in this case, the stress is specifically designed to affect you in ways that allow—or more accurately, force—your body to adapt for the better.
From the moment you start your first CrossFit workout, your body must work to meet the sport’s constantly varying exercises. Your lungs learn to function more effectively, your heart learns to pump more efficiently, your muscles get stronger to keep up with the demands.
In what is called general adaptive syndrome (GAS), our bodies respond to stressors in a predictable way. Scientists explain GAS as the body’s way of adapting to a perceived threat in order to better survive. GAS can be broken down into three stages:
Sound the Alarm
First we have the Alarm stage. In the first stage, the body encounters an “unaccustomed” stressor—in other words, a physical demand it currently isn’t capable of completely meeting. A distress signal is sent to a part of the brain called the hypothalamus, which starts a chain reaction that triggers the release of adrenaline—your basic “fight or flight” response.
This puts stress on your muscle cells; in fact, the point is to damage your cells by stressing them beyond their capacity, which mean you’re going to wake up sore tomorrow … but there is more to the story.
Resistance Is … Helpful?
Once your body starts settling down from the adrenaline rush, you enter into the Resistance stage. This is where your body tries to counteract the damage done during the Alarm stage. Cortisol levels drop, while your heart rate and blood pressure ease back toward normal. If this were the end of the stress situation, your body would return to its previous state during the Resistance stage.
For our purposes, however, that’s not helpful. You see, the body is efficient to the point of being lazy. It likes to keep things on an even keel, and doesn’t want to exert any more energy than absolutely necessary to stay there. But now, it’s freaking out a little: you just exposed it to a demand it was not at all expecting or prepared to meet. That stressor caused damage.
Logically enough, your body doesn’t want to go through that whole Alarm phase again. So if there’s a chance you might re-encounter that stressor sometime in the near future, your body wants to be ready for it. So in repairing the damage, it also builds up the muscle a bit … just in case.
This Is Exhausting
The Alarm and Resistance stages are necessary if we are to become stronger, faster, and more fit. And it can’t just be done once: that whole lazy-body thing, remember? If we go too long without using the new muscles we created, the body decides it doesn’t need to keep them quite so ready to perform.
Having said that, there is a danger of going too far the other direction, as well: if we don’t allow enough time—two to three days, sometimes—for the body to complete the repair process, we run the risk of moving into the Exhaustion stage. And that’s not good.
In the Exhaustion stage, cells are being pushed to the breaking point before being able to fully repair itself from the first round of demands. This restarts the Alarm process at a point where there are even fewer resources in the body to fight it. Given time, a pattern of insufficient repair time stemming from too many/too intense/too frequent training sessions will lead to overtraining … and eventually, a breakdown.
Putting It in Perspective
With all this in mind, it becomes easier to understand how CrossFit can and does improve athletic performance. We can draw a few conclusions from this.
First, the amount of time your body spends in the Resistance stage is extremely important. Rest is required for improvement. Second, your body can’t do all this work on a diet of Cheetos and Dr. Pepper: nutrition is a key piece of the puzzle. In particular, making sure you get enough protein means your cells have the circulating amino acids they need build more muscle strength.
Finally, we see why the stressor—that is, the specific movements—must be “constantly changing.” The guy who runs the same course every day, or the gal who hits the gym every day but does the same routine … honestly, they’re not helping themselves that much. Their bodies long ago adapted to the amount of energy it needs … which means it is back on its even keel and no longer making improvements.
At its core, CrossFit was designed so as to not allow such stagnation to occur. By intentionally giving your muscles and cardiorespiratory system something different every day, it forces your body to continuously adapt. In an environment where muscles and energy systems regularly encounter an unaccustomed stress, your body has no choice but to respond.