Why Benchmark WODs Aren’t Really Benchmarks.

Posted: January 29, 2014 in Uncategorized

One of the things that really surprised me when I began CrossFit, and perhaps one of the main points of criticism from mainstream fitness, is CrossFit’s use of “benchmark,” “prescribed,” or “rx’d” workouts, without respect to individual differences like height, weight, body type, current fitness levels etc.

After my level 1 Seminar (taught by an all-star team made up of Chris Spealler, Eric O’Connor, Miranda Oldroyd, Jason MacDonald, and Tommy Rudge) I was even more confused since CrossFit HQ doesn’t teach coaches to prescribe that way. In fact, the CrossFit training manual closely resembles typical prescription methods and specifically focuses on “Macro View” of constantly varied functional movements, “Elements of Modality,” “Workout Structure,” “Application” and “Scaling”.  In fact, as you can see in my personal notes from my level 1 seminar it says: In order to reach virtuosity you have to have: Mechanics, Consistency, and Intensity; and as a side note it says “Don’t focus on Rx, Progression is needed by everyone.”

Since it is the most well-known WOD, let’s take a look at Fran. The name enough sends chills down my spine. “Fran” (21-15-9 of Thrusters and Pullups) sucks pretty bad no matter what; let’s just throw that out there. That being said, there are biological and biomechanical factors that will make it suck more or less depending on the person. To demonstrate this idea, let’s take the equation used to determine Work (weight x distance), and apply it to two different individuals with different heights. (Keep in mind this equation only demonstrates work output, and does not take other factors, like limb length, joint angles, or basal metabolic rate into consideration).

Subject 1 is shorter than subject 2 and weighs approximately 135 pounds. Subject 2 is taller and weighs 185 pounds.  To measure their work output for Fran both athletes were recorded to allow the distance to be observed. Next we multiplied the distance by the force/weight (for thrusters it was 95 pounds and for the pullups, it was the athletes body weight.) Evaluating these athletes demonstrated that the shorter/ lighter athlete’s work load was 8% less on thrusters, and an amazing 36.5% less on pullups, for an average workload of 22.25% less than that of the taller/heavier counterpart!

Thruster FinalPullup Final

 

I initially started thinking about this after my Level 1 seminar, but more recently have seen it in my own CrossFitting. It is frustrating for someone like me who is tall (specifically with longer femurs and shorter torso) to continually struggle with my deadlift, and have someone walk into the box and deadlift just shy of 500 pounds their first deadlift workout! (Yes, that really happened) Speaking of deadlifts, lets pair it with another of my least favorite movements, the hand stand pushup, and evaluate the same subjects for the workout “Diane” (21-15-9 of 225# Deadlift and Hand Stand Pushups).

Ultimately the workload results for “Diane” were similar to those in “Fran.” The shorter and lighter athlete performed 17% less work in the deadlift, and 40% less when performing the hand stand pushup in comparison to the taller and heavier athlete. This means in a workout like “Diane” the smaller athlete completes and average of 28.5% less work than the larger athlete.

Deadlift Finalhandstand pushup final

 

As demonstrated in the examples above, there is an advantage for a smaller athlete in these two workouts. So benchmarks are only benchmarks for athletes who share exact characteristics. But that certainly doesn’t mean that smaller athletes have an advantage across the board. There are several movements and exercises that benefit a taller athlete. I would much rather throw a wall ball 2 feet to hit the ten foot target, than three or four feet. For rowing, a taller athlete is going to get more meters per stroke than a smaller athlete. Last year, I did the half marathon row with one of my coaches who is significantly shorter than I. After we were finished I was blown away to find that while I only finished about a minute ahead of him, he had rowed three strokes for every two of mine. Advantage definitely favors the tall in rowing.

This type of constant variability in both exercises/movements and advantages/disadvantages is part of what makes CrossFit unique, and using benchmark and/or prescribed WODs works well in competitions where athletes are performing many workouts in a short period to make sure to level the playing field as much as possible. That way, the best all-around athlete becomes the victor.

The issue, then, becomes that the large majority of CrossFitters are not games athletes or even potential games athletes. Most of us just want to be part of community, work hard, and improve our lives. Sure we will compete with ourselves and others, but as coaches and individual athletes we need to recognize that “Rx” is just a couple of letters, and “prescribed weight” isn’t the result of some magical exercise science equation.

Shouldn’t we look to prescribe our WODs a little differently? Why not use the simple work=force x distance equation to prescribe exercise. Adding time to the equation will still help with power production… It does require a little more work, but I think that injuries would decrease, and results would continue to increase. Instead of prescribing “Grace” (30 clean and jerks at 135# for time), maybe we say “choose a weight that you feel comfortable with, and perform x amount of clean and jerks until you hit 4,050 pounds, for time. Whether we are talking about 30 reps at 135#, or 60 reps at 68#, it is the same amount of work! Or maybe we say “Perform 30 reps for time of the clean and jerk at 60% of your 1RM.”

We looked at height, and saw that there are some real differences in work performed. There are other factors that could be evaluated to show even greater differences. Things like limb length, joint mobility, anaerobic and aerobic condition, motor skill development etc. Hopefully we as coaches and athletes can get back to the focusing on individuals and recognize that there are some real quantitative and individual differences in our work. If we can shift our viewpoint and not get hung up on always Rx’ing the WOD or trying to best everyone else in the box, we can expect to see real progress.

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Comments
  1. […] Me, I’m 5’10, and I just weighed myself in at 185lb. The more I read, the more I come to realize that being tall may be a distinct disadvantage in Crossfit, but that doesn’t seem to stop ladies like Lindsey Smith. And I don’t intend on allowing it to stop me. Just to put things in perspective the following is a great post on the biomechanics of height and Crossfit: https://crossfitbiomechanics.wordpress.com/2014/01/29/why-benchmark-wods-arent-really-benchmarks/ […]

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