In the 1930s Hans Selye from McGill University in Montreal developed a theory that is particularly influential in exercise science. His General Adaptation Syndrome sought to describe stress and the human body’s response to it. He describes two kinds of stress: eustress or “good stress” (stress we can recover from) and distress (stress from which we can’t). The human body adapts to stressors (anything that is challenging or demanding) by adapting (changing to be better ready to deal with the same stress in the future).


What does any of this have to do with CrossFit?


CrossFit is stress. Appropriately applied and scaled, it’s eustress. If every time you come into the gym, you aim to do just a little bit more than you did the last time, your body will recover and you will adapt. If you take two weeks off and decide to Rx an hour long met-con or do 100 heavy deadlifts on your first day back, you will exceed your body’s ability to recover, and be stuck in distress.


But what you do in the gym doesn’t exist in a vacuum. Stress outside the gym can also push you down into the stress hole. Large caloric deficits, poor quality sleep, family, work, or school issues—these are all sources of stress. If you reach the point where life outside the gym is rough and you try to push yourself too hard at the gym, you could very well end up further away from your fitness or body composition goals. Chronically elevated cortisol levels (a stress hormone) have been linked to muscle breakdown, body fat increases, and poor immune system function.


The main takeaway here should be to listen to your body. If you’ve had a long day, sometimes it’s okay to go 50% on a workout. Sometimes it’s okay to show up, talk to your friends, and ride the bike for 20 minutes and go home. Sometimes it’s okay to even *gasp* take a rest day.


Rippetoe, Mark, Andy Baker, and Stephani Elizabeth Bradford. Practical Programming for Strength Training. Wichita Falls, TX: Aasgaard, 2013. Print.

Verkhoshansky, Yuri, and Mel Cunningham. Siff. Supertraining. Rome, Italy: Verkhoshansky, 2009. Print.

Lon Kilgore. Adaptation for Fitness. 2010.