Reading time: 8 min 2s
December 11, 2015

CrossFit: Can Science Explain Its Success

Written by Damect Dominguez

CrossFit—both as a sport and a fitness methodology—is relentless in its growth. There’s no sign of it slowing down, but of course, most of you already know that. There are over 11,000 affiliated gyms worldwide and more than 250,000 athletes competed in its international competition, the CrossFit Games. Can all of this success be boiled down to a revolution in fitness or something else?

Although many may tab Glassman as an exercise genius, a scientific approach may also help explain the success of CrossFit. What is it about this sport, this methodology, that continues to attract new members and keeps them for life?

To have any successful exercise program, you need two things: human beings and human behavior. The amount of research that goes into performing movements, building strength and pushing the limits of the human condition (or what Glassman calls “genetic potential”) is well known. However, what many don’t consider is the behavioral science behind it all. Just like gravity pulling heavy barbells back down to Earth, the science of human behavior will always predict who continues to show up, hit PRs, and make strides with their fitness goals each and every day. This scientific approach will be helpful for any athlete, powerlifter, Olympic Weightlifter, or box owner, regardless of experience or skill level.

CrossFit is concerned with functional movement. Behavior analysis addresses the functions of our behavior (why we say the things we say and do the things we do). Each of our individual behaviors has a purpose or function, and can be measured. If you can see or hear it, it’s behavior.

Our measurable behaviors change the environment around us and make an impact. Repeatedly observing and measuring behavior allows us to predict what will happen in the future based on how the environment responds.

Our actions in and out of the box result in something gained or something lost. For the most part, when good things start to happen as a result of our actions, we tend to do more of those things. When you listen to your coach and get under the bar more quickly as a result, you’ll continue to listen to your coach–correct? And if you are a coach, how did the athlete’s performance (good or bad) affect the way you continued to coach? Did you use the same instruction or try something new? Of course, if some actions produce a less desirable result, we tend to shy away those actions. Think of the time you had a bad experience when trying a new gym–it’s unlikely that you would return to that box.

The concept of reinforcement

When our actions are followed by positive consequences, we are more likely to do them again and again. Reinforcement has two basic forms: Social reinforcement and automatic reinforcement.

Social reinforcement

includes consequences provided by our friends and coaches such as conversations on technique before class, cheering us on during a competition, and getting a fist bump after a big lift. Can you think of the athletes in your box that are motivated by seeing their name at the top of the whiteboard? Or do you show up at certain class times to compete against other members like I do?

Sometimes, too much social reinforcement may not be in your best interest. Can you remember a time when you were talking with friends when you should have been mobilizing and warming up for strength work? Coaches, you probably have a couple athletes in mind already…

Automatic reinforcement

includes consequences that occur without influence from other people. This can take the shape of seeing your scores (and reacting negatively or positively), feeling and looking healthier, going to that “dark place” during a WOD, or experiencing gains in power, flexibility and endurance. You train regardless of whether or not anyone notices. Improving your time or hitting a PR is good enough for you, and it doesn’t matter what others say. This may be more akin to the solo garage gym athlete. While you are working out, nobody is around to provide you with social reinforcers (“Great Lift!”).

Reinforcement in action

Whatever the source, as long as reinforcement is present, then you will continue putting in hard work. Successful lifts are the result of many things (flexibility, strength, stable midline). Most importantly, timing is key. The same goes for reinforcement. Reinforcement always occurs after the behavior of interest. When certain behaviors continually produce particular outcomes, the more we see of these behaviors. That’s the basic science behind it.


For instance, consider the action of posting workouts and lifts to social media. Online posts often produce an immediate consequence: social reinforcement. You receive 10-15 likes, winks, and emoticons within 5 minutes of your post. If this type of reinforcement is important for you or your business, you will probably continue posting in the future. Makes sense right? How likely do you think you would continue posting new PRs (or fails…those receive a LOT of social attention) if you did not receive any attention from social media? If there is no reinforcement, then you stop posting pictures and videos. Simple as that.

You can think of the different types of reinforcement as a plate on the barbell. Each plate will vary in size and weight (the effectiveness), but the more plates you load onto the barbell (the more reinforcement that is available), then the more a particular behavior is reinforced. This translates to consistency and higher performance in each athlete (Even though in reality, the more plates you put on the barbell makes it harder to lift, it works as a nice analogy so work with me here ☺). And of course, there are training days that are better than others. We hit strength plateaus, the head strength coach is out of town, or class numbers are low. Fortunately, other forms of reinforcement help us finish workouts and strength programs.

Using the barbell analogy, various sources of reinforcement (physical gains/weight loss, equipment, increased social circle, feedback from coaches, skills learned) are most often present in CrossFit boxes. See the picture below.

cf reinforcement

For one athlete, physical gains (largest/blue plate) may be more valuable than other forms of reinforcement. Other smaller plates (coaching, skills) may play a smaller role in your success, but are still a variable nonetheless. The globo gym athlete’s barbell like this:

globo reinforcement

What about when you train at a gym with awesome equipment, but lacks in other areas of reinforcement (coaching, community)? I never enjoyed waiting for the bench press during my globo gym days. When you go to a gym just for their equipment (the biggest plate), and you cannot use it, that is incredibly frustrating. So, do you start shopping for other gyms if it becomes a perpetual problem? If so, it is because the reinforcement has disappeared…and so does your behavior! No equipment, no you! Again, certain plates may or may not be important to you.

For the garage gym athlete, the reinforcement barbell could look like this:reinforcementYou receive online coaching, learn how to create programming, and can achieve incredible results. You have great training equipment and have success in a variety of CrossFit-style events and weightlifting meets.

Essentially, the more plates a gym has, the more likely it is to succeed. The barbell analogy above and combinations are hypothetical, but I would place my bets as to why so many people join CrossFit: CrossFit boxes have more plates to offer and are readily available. Most importantly, the combination of the social environment coupled with the overall physical health and wellness benefits works for most people, and this is what makes CrossFit unique and very successful.

Affiliates vary widely, but the differences come down to the amount and types of reinforcement that is available in each box. As a box owner, what type of reinforcement sets you apart from other boxes? As an athlete, when comparing memberships, why might you choose one box over another? How does it relate to reinforcement?

As a quick review, I have noted that CrossFit offers many forms of both:

Social Reinforcement:

  • Meeting new people
  • Becoming part of a community
  • Availability of coaching
  • Learning new skills and movements
  • Winning monthly box (placement in the Open) or local fitness competitions

Automatic Reinforcement:

  • Increased strength
  • Added mobility
  • Improved endurance
  • Weight loss
  • Improved physique
  • Improved well-being

Overall, we see how a principle of human behavior (reinforcement) can help explain CrossFit’s success. Reinforcement doesn’t happen once or twice or end when you leave the gym. It is a part of our everyday lives. We always need to be on the lookout of how we can encourage, praise, coach, and provide meaningful consequences to others as they engage in the behaviors (good form, showing up on time) we want to see more of.

Human behavior is complicated, and it might not be obvious at first as to why certain actions are happening. Reinforcers are different between people, can change or be a combination of more than one at a time. Coaches, are you assessing your athlete’s motivation during your initial paperwork? Every day? Once a month? Not at all? Athletes, what plates are most important to you? Are any missing or not living up to your standards? What can you do to change your environment to maximize the plates on your barbell? Once you have these answers, the next step is to start measuring the behaviors and the environment around you and track your progress.

If we answer two questions each day, then we can guide our own success:

How full is my barbell?
What plates are loaded?

reinforcement what plates

About Damect Dominguez

Co-founder of BoxLife Magazine. Author: Training Day: 400+ Workouts to Incorporate in Your Training.

Leave a Comment