CrossFit is referred to as a General Physical Preparedness (GPP) program. Its intent is not to cause specialization in any one of 10 critical areas, but rather increased performance across all of them so the individual athlete is prepared for whatever life throws at them. The “official” aim of CrossFit is:
“Increased work capacity across broad time and modal domains.”
In plain English, as CrossFitters, we simply strive to improve a range of activities such as a weightlifting Snatch 1RM performed in a very short period of time to something like a metabolic conditioning 2000 meter row which occurs over a longer period of time. Each of these activities, and those between and beyond, utilize differing metabolic pathways in differing ways; training across a broad range of activities optimizes these metabolic pathways and leads us in a positive direction towards health, fitness, and longevity.
Once we complete Elements and start to get comfortable with certain moves, many CrossFitters are faced with the quandary: “What weight should I use for this WOD?” This, of course, varies with the rep scheme of the WOD as well as training status and experience of the given athlete but one should always keep the overall aim, mentioned above, in mind. So I ask you this: Is it possible to INCREASE the power output of a given workout by DECREASING the weight one uses?
In order to answer this we’re gonna have to geek out just a bit, so bear with me…
Work is defined as Force X Distance (F X D). Simply put, it’s the energy required to move a weight a given distance. If you divide the result by the time it takes to move the mass the given distance, the result is called average power (aka “work capacity”).
Let’s consider a simple WOD consisting of 45 Thrusters, for time, at a prescribed weight of 95 pounds. And let’s say it takes an athlete 5 minutes to complete the work. In our example, from the bottom of the squat to the overhead position is a distance of 6 feet. So our calculation looks a little like this:
W = F X D6 feet X 95# = 570 foot-poundsP = W/T570 ft-lb/300 sec = 1.900 Watts*
*(Coincidentally, a more commonly used unit of power output is a Horsepower, which is equal to 746 Watts, so our athlete demonstrated a work capacity of 0.0025 HP).
After finishing, our athlete feels the 95# weight really slowed him down so, after a few days of recovery, he decides to repeat the WOD with a scaled weight of 75#. By dropping the weight a little over 20% he is able to complete the WOD in 3:30. Now let’s go back to our original question – Is it possible to INCREASE work capacity by DECREASING weight?
You bet it is. Let’s prove it:
6 feet X 75# = 450 ft-lb450 ft-lb/210 sec = 2.143 Watts or 0.0029 HP
In this case, decreasing the weight allowed a significantly faster time which resulted in a 16% increase in work capacity. Kristin, check my math.
You're probably wondering how this info is useful to you? Should you bust out an abacus and slide rule before every WOD? Well…no, not unless that’s your thing, but it is helpful to understand the concept at least so you don’t get hung up on using the Rx’d weight for a WOD. In fact, if you’re at the box long enough you’ll probably see some folks come and go that simply aren’t able to check their ego at the door and insist on doing Rx’d weight no matter what. If you watch closely enough, you’ll cringe at the sloppy technique, rapidly deteriorating form, or injury. Simply put, you may very well get a better workout, and thus better results, by scaling and making small, incremental steps towards Rx'd weights.
Speaking of prescribed weights, it’s important we remember they are intended for “Elite” athletes. Each of us has strengths and weakness, and while we all are striving for maximum performance, the journey to get there goes from Untrained to Novice, then Intermediate, Advanced, and finally Elite. I refer you back to our welcome post with the suggestion to truly gut-check where you are reference to some defined “standards” and set goals accordingly.
One last thought I’ll leave you with…It is damn-near inevitable that each of us has compared ourselves to others on the board at the box. Maybe you’ve even used others’ performance as a “guide” for setting up your WOD. This can be OK if you're using the information wisely. The caution I offer is this can be either beneficial or detrimental to your results. Unless the individuals you are comparing yourself to are similar in age, physical stature, training status, experience, nutrition and recovery, the comparison is likely moot; a better suggestion is to compare your results to YOUR results. Keep an organized workout journal and get with one of the instructors to help you shore up areas that are lagging.
If you are competition-minded or absolutely, positively must compare yourself to others look into a membership* at Beyond The Whiteboard. This tool allows you to log your personal stats and WOD performance and then stores it in a database with thousands of other results. You can do comparative searches based on criteria such as age, height, weight, etc. It yields results in a bell-curve format so you can see where you are relative to comparable peers. It’s a much larger sample size and can give you a better idea of where you truly stand as a CrossFitter.
*Until recently BTWB was "open" to view others' WOD results but it looks like this may have changed. They do offer a free 30-day trial if you'd still like to check it out.
I've seen some people beat themselves up about not being able to do Rx'd weights, or attempting to and ending up frustrated with their performance -- I've been guilty of both myself. As the Challenge comes to a close, I hope you keep this post in your mind as you proceed with your training. It's not an excuse to not push yourself but rather a challenge to train smartly, efficiently, and safely. I've enjoyed writing these posts and working with all of y'all. See ya' at the box!
3, 2, 1...GO!