Intensity and variance are critical components of CrossFit programming. Intensity drives the tremendous results CrossFit athletes experience, and variance develops the broad, general, and inclusive fitness we’re after. We must preserve the intended stimulus for each workout to ensure we optimize for both intensity and variance in our programming. Here are five factors to consider when determining the desired stimulus of a workout:
#1 – How the workout feels
Is it a lung-burner? Is it heavy and slow, or will it cause muscular fatigue in specific areas?
#2 – Loading
Is this a heavy workout where the loads challenge the athlete between 1-5 reps and a longer rest is required, a moderate workout where the athlete can perform 6-20 reps with the load and requires moderate rest, or a light workout where the athlete can handle sets of 20+ reps with short rest. This heavy, moderate, or light classification applies to weightlifting movements and gymnastics movements. For example, a muscle-up is a heavy gymnastics movement, a push-up is moderate, and an air squat is light.
#3 – Timing
Is the workout designed to be long, medium, or short? For example, Fran is meant to be a short, intense workout, so loading for the thrusters and pull-ups should be scaled appropriately to preserve this stimulus. Cindy is a longer workout intended to keep the athlete moving continuously for 20 minutes, which may require athletes to scale movement patterns or the rep scheme.
#4 – Volume
Does this workout intend to accumulate many reps or rounds (like the Filthy Fifty or Fight Gone Bad), or is it a lower-volume workout consisting of fewer reps or rounds, such as Grace or a heavy deadlift day? Volume is correlated with loading in that high-volume workouts tend to use lighter weights, and lower-volume workouts use heavier weights.
#5 – Movement patterns
Does the workout include an upper-body push or pull, a deadlift variation (hinge), or a squat? Ideally, we want to preserve the programmed movement patterns as much as possible for each athlete.
Consistently preserving the target stimulus across varied programming ensures we hit the full spectrum of intensity levels. This enables us to increase capacity in all areas, which is critical for optimizing results over the long term. If, however, we ignore the intended stimulus and bias our workouts toward what we’re good at or prefer, we’ll hamper the depth and breadth of our fitness development.
If we always do long, slow workouts, we’ll struggle with heavy days and short, high-intensity challenges. If we always lean toward heavier loading, we won’t do well with long, light, and fast workouts. We’ll find any movement patterns we consistently avoid difficult to perform. Fortunately, with some math, practice, and common sense, we can get very good at hitting the stimulus. We simply need to understand how long a workout should take in the case of a task-priority workout or how many reps or rounds should be completed for a time-priority workout (AMRAP). This guides the scaling of the above elements so athletes hit the intended time or rep targets.
How to Determine the Stimulus: the Math Method
The math method is a simple and effective way to determine the length of a workout or the number of reps an athlete should complete in the designated time. It entails calculating the time required to perform each exercise, along with estimates for rest, transition times, the effect of fatigue, and a little common sense to double-check our work.
Example 1 — Fran- 21-15-9 Reps for Time of: Thrusters and Pull-ups
Fran consists of 45 thrusters and 45 pull-ups. A thruster takes about 2 to 3 seconds to complete, so it takes about 1:30 to 2:15 to do 45 thrusters. Each pull-up takes 1 to 2 seconds, so we’ll need 45 to 90 seconds for 45 pull-ups. That gives us a 2:15 Fran if we use the fastest numbers for each movement. Add a little time for transitions, rest, and slowing due to fatigue, and a reasonable estimate is that our fastest athletes will complete Fran somewhere around the 3-minute mark.
Now, we just need to set the time for the slower side of the range that still preserves the stimulus. A simple rule of thumb is to set the slower time at double the fast time. We don’t want slower athletes moving for more than twice as long as the fastest athletes because it indicates they are resting too much and their intensity is too low. For Fran, we’ll set the slower time target at 6 minutes. Through scaling load, reps, and movements, we can ensure most of our athletes fall within this range (or at least close to it) and hit the stimulus.
Example 2 — Cindy- 20-Minute AMRAP of: 5 Pull-Ups, 10 Push-Ups, and 15 Air Squats
We can use the math method to determine a low and high range for rounds by calculating how long each round might take for faster and slower athletes. Allotting 5 seconds for 5 pull-ups, 10 seconds for 10 push-ups, and 15 seconds for 15 air squats, we get 30 seconds for a round. Based on those numbers, we’d expect our fastest athletes to get 40 rounds in 20 minutes. If we divide the work done by the fastest athletes in half to determine the target for slower athletes, we get 20 rounds. Experience and common sense tell us both of these numbers are too high.
For a workout this long and with this many reps, we must account for transitions, rest, and fatigue. It is not unreasonable to expect an average athlete to average 20 seconds for the pull-ups, 40 seconds for the push-ups, and 40 seconds for the air squats, totaling 1:40 per round. This shakes out to about 12 rounds in 20 minutes. That’s a good low-end target; 24 rounds or so is a good high-end target. If athletes get less than 12 rounds, their version is too difficult — they are resting too much and missing out on the intended intensity. Scaling variations such as ring rows, elevated push-ups, or altered rep schemes can all be used to ensure most athletes fall within this range and hit the stimulus.
Example 3 — Amanda- 9-7-5 Reps for Time of: Muscle-Ups and Squat Snatches
If we calculate 3 seconds per muscle-up and 3 seconds per squat snatch, and add a little time for transitions, we might expect Amanda to take 3 minutes or so for our fastest athletes. Doubling that time sets the target for slower athletes at 6 minutes. However, neither time is reasonable because the movements in this workout are high-skill and moderate to heavy in load. This means more rest is required during the workout, so we must expand the time targets to accommodate this. Around 4 minutes is reasonable for the fastest athletes. For our slower athletes, 9-10 minutes is realistic. If an athlete is slower than 10 minutes, the intensity drops too much. As with the other workouts, loads, reps, and movements are scaled to keep most athletes under the 10-minute mark so they hit the stimulus.
Results
Understanding the intended stimulus of a workout and scaling the workout to achieve the stimulus at our own fitness level is crucial for implementing CrossFit properly. Consistently preserving the stimulus of the workout ensures we maintain the variance and intensity we need to develop a high level of work capacity across a broad spectrum of challenges. Use the math method to help guide your scaling choices, and you’ll be astounded by the intensity of your workouts and results.
About the Author
Stephane Rochet is a Senior Content Writer for CrossFit. He has worked as a Flowmaster on the CrossFit Seminar Staff and has over 15 years of experience as a collegiate/tactical strength and conditioning coach. He is a Certified CrossFit Trainer (CF-L3) and enjoys training athletes in his garage gym.
Hitting the Stimulus in Each CrossFit WOD