The SRA Curve: You Don't Grow in the Gym
Updated: Jul 25, 2021
We live in a world where everyone thinks more is better. More money, more food, more friends...
This even carries over into the gym. People have developed the mindset that if they just do more each session they will see better results. They think that you are getting bigger and stronger in the gym. The reality is that we make gains from recovering from what we do in the gym.
In order for our muscles to grow larger, and get stronger they have to go through a process where they are stimulated, where they recover from the fatigue that comes along with that stimulus, and then finally they can adapt and grow. This process is called stimulus-recovery-adaptation (SRA), and can be represented visually by a graphed curve.
In this article we will review what this curve looks like, why it's important, and how to manipulate it to improve your programming and training.
What is the SRA Curve
The SRA curve is incredibly simple to look at despite representing the very process of improvement.
I have provided an example and used different colors to represent the different stages. The horizontal line on the graph represents your baseline of performance. This could be how well you performed a 5x5, how fast you ran a 5k, anything training related.
The changing line on our graph is going to represent where our performance levels are during each stage of the curve.
The start of this graph represents a training session. You go in and perform a bench session. This is the stimulus for your pressing muscles to grow bigger and stronger.
But before that training session has even finished the red line on the graph has begun to dip down. This drop from baseline performance is due to the fatigue developed from the training session. This starts after your first hard set is completed, you get more and more tired as the session goes on, and continue to hold onto the fatigue for hours and days after the training session.
The chances of you doing a very hard, grueling bench session and coming back an hour later and being able to match that performance are pretty slim.
With this we can see that it's not the training that's making us stronger, if anything it’s actually making us weaker, but it does provide the catalyst for improvement.
Once our fatigue reaches our peak it begins to change direction and moves into the next phase: recovery. This is represented by the green section of the curve.
During this phase muscles and nervous systems begin to return to their previous level of performance. This happens as we eat, sleep and rest.
At the peak of this phase we would be able to go into the gym and match our performance from the last session, but that's not what we are after. We are after progress. This occurs in the final stage.
The blue line jutting up from our x-axis represents the adaptation phase. When our body super compensates for the last session and we become bigger and stronger. It is when this hase peaks that we ideally want to be training that movement or muscle group again. If we time this right we should be able to get more reps or add more weight to the bar.
It is the process of going through these phases and trying to time training sessions for once the adaptation process is completed that creates the equation for making consistent and reliable gains.
This can be represented visually by this graph. You can see that this accumulation of SRA phases is resulting in a gradual increase in performance.
So many people get caught up in getting the most of a single training session when they should realistically be setting themselves up for the next one.
It is the recovery from session to session that allows us to progress, not the fatigue from the session itself.
#1-Training a muscle group to frequently
This is a common practice in many people who try to cross train. They often overlook the impact that running, other sports, and whole body workouts will have on the recovery from a previous day's session.
Training Legs hard on Monday and doing a long run on Tuesday may not allow you to recover in time for another leg session on Wednesday.
Or doing a several shoulder dominant Crossfit Wods back to back each day may leave you underperforming on your Jerks later in the week. Disrupting the SRA cycle can rapidly compound if programming isn't thoughtfully laid out resulting in high fatigue, reduced
performance, and potential injury.
#2- Not training a muscle or lift frequently enough
On the other side of the same coin is the issue with not training a muscle frequently enough.
“Bro splits” are accepted as programs where you train each muscle group once a week. While there is typically a higher level of volume per session, you are stimulating the muscle less frequently.
This may actually result in a detraining effect where your performance begins to decline from its post adaptation peak. While this does take some time to happen, you may be losing potential gains over time.
The research suggests most muscle groups benefit from 2-3 times per week training with around 24-72 hours of recovery in between sessions to maximize muscle growth.
#3- Too much Volume per session
We know that volume is the biggest contributor to fatigue. The more hard sets you do per session the bigger the stimulus for growth will be, however your fatigue will also rise.
When people move from a once per week frequency to a higher frequency, such as twice per week with a push/pull/legs split, they often make the mistake of trying to match the volume of intensity of their old sessions.
They may have been doing 15-20 sets per workout before, and that meant 15-20 sets per week. If they try to do that twice per week their volume jumps up to 30-40 sets. This becomes very hard to recover from on a weekly basis.
However there is another issue with this. As you will be training more muscle groups per workout your intersession volume will sky rocket. If you do 15 sets for chest, 12 sets for shoulders and 10 sets for triceps you are now doing 37 sets in a workout. If you are capable, and used to 20 sets max in a workout, the quality of those last 17 sets is going to be greatly diminished. These sets will turn into junk volume, or volume that doesn’t at much stimulus but still adds a disproportionate amount of fatigue.
This may all result in you creating such a fatigue debt that you are unable to complete the recovery and adaptation phases of the SRA curve before your second session comes around.
A Longer recovery phase equals a shorter adaptation phase between sessions which means a lower performance increase,
While simplistic in presentation the SRA curve is a very important consideration when adjusting training variables.
It will help drive decisions in regards to training frequency, resting frequency, volume per session, volume per week, cross training with the goal of maximizing gains.
Approach your training sessions like you are setting yourself up for your next one and focus just on much as recovering as you do training and your rate of progress will skyrocket.