What’s Rx?

Have you ever asked this question? Ever started off the first round of a workout blazing, adrenaline pumping, completing the reps faster than everyone – and ended the last round with taking twice as long to finish, or with half the reps of the first? Are you always time capped?Have you had to decrease the weight you chose for the WOD midway through? Or started off with cleans looking near perfect and absolutely abysmal by the end (and maybe injuring yourself)? 
We’ve all done it, don’t worry. This isn’t an attempt to shame anyone – we’ve all been there. This is an attempt to provide an insight from the coaches’ side into why we may tell you to take LESS weight or SLOW DOW in a workout sometimes rather than FASTER and MORE WEIGHT. 
Why? Surely more weight is better? Faster is better, no matter what the cost? Everyone should do Rx? 
Nope! 

First we ned to define: what actually is Rx?

Rx is determined depending on who programmed the workout. The crossfit.com workouts and benchmark workouts will use a slightly different scale for Rx than your local box. Benchmark WOD prescriptions are generally designed Regionals-level athletes. Boxes will likely have a slight skew on what their Rx is depending on their athlete population; you may have noticed when you travel, different boxes have different Rx prescriptions. 
For time-priority workouts, the measure is pretty simple; if you’re not finishing the workout under the time cap, you need to scale. Like, Rx weight for Fran should allow you to finish in less than 5 minutes. If you’re taking longer, you need to scale. 
The coach (or other athletes’ scores for a workout) should give you an indication of the goal for total time, time splits of rounds, reps completed, or percentages of your max for weights to use in a workout. For example, in a 15′ AMRAP of 10 squat cleans and 15/20 cal rower, the coach should be providing guidance in the movement prep in the form of; 

  • Pick a weight you can break up into max. two sets for the cleans. 
  • The calories on the row should take you under one minute, if it takes longer you should scale down calories. 
  • You should aim for 6-7 rounds in the 15 minutes. 

With this information in mind, you then should NOT be picking your weight based on what you see on the whiteboard what Bob did this morning for his cleans, and doing the Rx calories on the rower even though it takes you 90 seconds to complete them. 

Similarly with high skill movements; when a WOD includes toes to bar or double unders and you’re not able to complete these movements with proficiency yet, but insist on doing them “Rx” anyways, you’ll either end up being time capped or complete so few rounds that you’ll finish the workout frustrated, not sweaty, and without having improved your fitness. Choosing high knees and single unders would have allowed you to get a good challenge in for your conditioning and improve the basic skills that will later allow you to better your higher skilled movements. 

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How do I know if I need to scale?

If you’re not finishing the workout under the time cap, you need to scale. If you’re working at weights or movements that you’ll be moving at half the pace of other athletes, you need to scale. If your form looks terrible, you need to scale. There is no shame in scaling!

Why is it so much better to scale?

All workouts are designed with a specific goal of metabolic or nervous system adaptation in mind. Perform at a level that allows you to achieve the intention of the workout, ie “the stimulus”. This is best demonstrated by short, benchmark workouts, but can be applied to longer ones as well – a series of AMRAPS as well as Fran or Grace.

Scaling enables you to get the intended stimulus


Take Fran: 21-15-9, thrusters and pullups. Elite athletes are completing this workout in under three minutes, no problem, with Rx weights and butterfly pull-ups. Those three minutes are extremely intense, pushing them to their limits, almost no breaks, barely time to breath. If you are an average CrossFitter, take Rx weight for Fran, and have to break up the thrusters into sets of four and also try to do kipping pull-ups even though you can do maybe doubles or triples before you need a rest – it will take you maybe 10 minutes. After you’re done, maybe you’ll be pretty tired, but you probably won’t need to lie on the ground and catch your breath for 5 minutes after… because you didn’t reach the intended level of intensity, the intended stimulus. 
The lesson? If you can’t complete the workout at a high level of intensity, scaling is your friend: reduce the weight, do the thrusters unbroken, do jumping pullups and only rest once or twice and you’ll be done in 4.5 minutes – at the intended level of intensity to reach the stimulus. 


The same can be applied to a 30’ E3MOM – if in your first round, you’re done with the movements in 60 seconds but the last 4 rounds you’re barely finishing, or maybe not finishing at all, then you’re not reaching the intended stimulus for the workout. In this case, you’d want to pick weights and speeds that allow you to maintain consistency throughout the 10 rounds as much as possible. 

Mechanics, Consistency, and then, only then Intensity

I want you to have the goal of, at the speed and load you choose, to perform your last reps looking almost as good as your first. I use the words goal and almost purposefully: this doesn’t mean it will be achieved, but if you go in with the intention to execute as such, you may come close to reaching it. If we aim for perfection, we may achieve excellence. If you’re constantly moving with intensity at higher loads than your body can move well at, you’re engraining poor movement habits, not reaching full ranges of motion, and putting stress on joints and tendons that they aren’t designed for. 


Taking a step back and working at lighter loads to establish good, functional, full range of motion movement patterns may not be sexy or cool, but the long-term payoff in the long run is where you should keep your sights set. Invest in your future self by moving well today. 

Injury: Risk vs Benefit

A risk-benefit ratio is highly subjective and very nuanced – but it’s not worth taking that extra 10kg for a jerk or doing those last 5 thrusters where your back is hyperextended if it means the risk is an injury. Especially if it’s potentially an injury that puts you out of training for months at the benefit of using the same weight as your buddy next to you. Doesn’t seem like a great risk-benefit ratio. Get to know your body, tune into it, and respect your own limits. Being pushed by other members is awesome and part of why you come to train in a group. Going past your limits that you know deep down is too far, only for the sake of intensity, at the sacrifice of moving well – is not so awesome.  

We hope this helps you gain an insight into your training habits and check your ego next time you think about listening to what Rx is or what your buddy is doing rather than knowing your own body’s capabilities. 

‘Written by

Claire Wolfert

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