I was having a conversation about intended stimulus for the workout of the day recently, and I realized it's more than likely a question several people have. It's not always easy to explain, but the truth is it's really not all that complicated either.
CrossFit itself is defined as a strength and conditioning program consisting of constantly varied functional movements executed at high intensity across broad time and modal domains.
But what does that exactly mean, and how is it related to intended stimulus in a workout? More importantly, what does that mean to me as an individual?
The intended stimulus of a workout is different from day to day. The reason for this is that it's constantly varied. It's designed to stress our bodies in varied ways for varied amounts of time--so they adapt to the stress and become stronger. That's how we increase our fitness. It's an incredibly effective process that touches on pretty much every aspect of strength and conditioning.
For today's workout, the stimulus might be to get it done within a specified period of time. Or, maybe it's to accomplish a specific number of reps as fast as you can. It could be to do lighter reps fast (high volume), or heavy reps more slowly (low volume), or maybe it's a long chipper that you have to push through mental walls and figure out how to pace yourself in order to get the work done. And other days, it'll be a short duration sprint to see how fast you can go. It all depends on what the workout is designed to help your body achieve. We stress your body in different ways--it's systems get stronger, and you become more fit. Next time, you'll be able to achieve more in the same or a similar workout. This is increased work capacity, which is also how CrossFit defines fitness.
The important thing to know about the intended stimulus for any workout, is that it can be adjusted to every level. We can take any workout and scale the number of reps, the amount of time, the weight, the distance--any aspect of the workout at all--to fit the individual athlete. This helps to ensure every person can do the same workout and finish in roughly the same amount of time--it preserves the intended stimulus. This is another reason why trying to RX a workout every time is a mistake--trust the process and stay within the time prescribed framework so you can realize your potential, and get the best possible results from your workouts.
If we take the benchmark workout, Fran, as an example: it's a workout designed to make you push yourself to your limits within a short period of time. Everyone in the class from elite to intermediate to beginner athlete should be able to finish in 7 minutes or less.
Fran consists of 21-15-9 thrusters and pull-ups as fast as possible. It has made me want to cry (probably because I didn't scale enough though). To preserve the intention: high intensity, fast pace, finish within prescribed time, we make the movements accessible for everyone in the class. That means scale the thrusters weight, and/or possibly modify pull-ups to banded, jumping, or ring-rows).
If I know I can do 95/65# thrusters, that doesn't mean I should for this workout. Why? Because I know I won't finish in under 7 minutes if I do. I need to scale the weight in order to make sure I can meet the time requirement, and thus preserve the intended stimulus.
The benchmark workout, Cindy, is different. It's a long, low intensity workout with the intention of testing skill and stamina. It consists of as many rounds as possible (AMRAP) in 20 minutes of 5 pull-ups, 10 push-ups, and 15 air squats. I would only need to scale for skill (possibly banded or jumping pull-ups (or ring-rows), push-ups from knees, off a box or wall, and/or possibly air squats to a target for example). The number of rounds and reps I'm able to accomplish will be determined by the timecap. The next time I do this workout, I can try to beat my own time.
The next time you see a workout on the whiteboard, try to see if you can figure out what the intention behind is; you can ask coach if you're not sure. Stay within the prescribed limits of the workout so you can scale properly. This will allow you to adjust the workout for where you are today, knowing it will increase your fitness effectively--and much more safely than attempting to do more than your body is adapted for yet. At the same time, it will empower you because you'll know you've made the changes necessary to preserve the intention behind the workout.