Chasing the RX Button & the Purpose of Scaling


When you come into CrossFit there are many new things to learn.  I believe that your first several weeks to months are akin to learning a new language.  What’s an AMRAP, EMOM, METCON, THRUSTER, C2B, TTB, SDHP, etc.  Along with all of the abbreviations we also throw numbers such as 60% x 5, 75% x 3, 90% x 1 to make you even more confused (just kidding). There is a rhyme and reason to all of the vernacular that is used and one of the most important abbreviations is RX.  As Coach Michelle went over in an earlier blog post, the RX button means to perform a workout as prescribed.  This article will discuss as to why “Chasing the RX Button” and not scaling appropriately is often misguided, counter-productive to our goals, and often times leads to injury.

Among many CrossFitters, being able to perform Metabolic Conditioning segments as prescribed is seen as a right of passage.  Many times individuals will choose to perform movements that they are not proficient in and weights that are too heavy for them in an attempt to perform a workout as prescribed.  We will start with an example in order to describe how to use proper scaling to achieve the targeted response to a workout.

Example: FRAN (The most famous or infamous CF workout)




What this means is that you will perform: 21 Thrusters, 21 Pull Ups, 15 Thrusters, 15 Pull Ups, 9 Thrusters, 9 Pull Ups

The RX (Prescribed) weights for thrusters are 95 lb/males and 65 lbs/females.  The RX (Prescribed) for pull ups is to start on the bar with elbows fully extended and with the chin reaching over the bar.  

Time Frame of Fran:

The time to complete FRAN will be around 2:00 from the fastest in the world and really should take no longer than 7-8 minutes.  

Who should perform this RX?

The answer to this is a little tricky, but here are some general guidelines:

  1. The thruster weight should be no more than 50-60% of your thruster 1 RM
  2. You should be able to perform a minimum of 10 pull-ups unbroken when you are fresh. (Kipping Pull Ups are recommended for those with competency)
  3. You should be able to perform both the thruster and pull up with competency of the movement under fatigue.

Why does it matter?

This is very important as we are performing this workout in order to attempt to produce a very high power output.  A quick physics lesson for everyone…

Power = (Force x Distance)/Time

As you can see TIME is very important in our Power output!!!

A major cornerstone of the CrossFit philosophy is to increase our power output as we train. As we increase our ability to improve our power output our fitness improves.  When we do not scale appropriately we inhibit our ability to train at a proper threshold that is needed to make improvements and adaptations.  

What does this mean?

During FRAN or any other workout you should always pick an appropriate weight and or movement to complete the workout.  This may mean:

-Choosing a Lighter or Heavier Weight

-Choosing to perform a different movement (Ring Row in place of Pull Ups)

-Changing the rep scheme ( Replacing 21-15-9 with 15-12-9)

The Ugly Side of Chasing the RX Button

If you have been around CrossFit long enough you have most likely seen many people fall to pieces during FRAN and take 10-15 minutes to complete it.  This typically manifests itself in each thruster looking like max effort with weight shifting to the toes, and rounding of the spine.  For the pull ups it typically looks like the athlete is potentially having a seizure while attempting their pull ups (often times 1 painful rep after another).  

When this happens, you are not achieving the purpose of the workout and are training at a much lower threshold than originally intended.  When not training at proper thresholds, you will not see adaptations.  And adaptations are typically why we work out, to become stronger, faster, healthier?  The guy using 95lb and taking 17 minutes to complete Fran has not only produced less power output than his counterpart who used 75lb and completed Fran in 8 minutes, but also never achieved the appropriate intensity level and didn’t provide his body the proper physical and neurological stimulus to produce adaptations.

Our Pledge at CFP

You will notice that for many of our metabolic conditioning segments that involve a barbell we often use percentages of your 1 Rep Max instead of an arbitrary number.  We believe that this helps direct members in the right direction.  Before every workout, we always perform movement demos as well as scaling recommendations.  Our intent is to put all of our members in the greatest position for success.  If you ever have any questions about what weight or what movement you should be performing, we always want you to speak up and ask one of our great coaches.
Dr. Warren


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s