Structural Integration is different from massage therapy, acupuncture, stretching, exercise, chiropractics...
It is not the type of modality to do preventatively. It should be seen more similar to physical therapy, or something you do in a round to recalibrate the body.
I recommend choosing a time in your life where you are able to commit to a series of session in a shorter window of time. These sessions build upon one another and are aimed to assist your body in creating new habits and neural pathways...this is how you create long lasting change.
If you want to experience total-body rebalancing but do not have the resources (time, money, energy, etc.) to commit to the 12 Series protocol, you CAN do a shorter series.
You can do a 3 Series.
This is the generally the first 3 sessions in of the method (sometimes a little different). Front, Back and Lateral lines. This makes up the superficial fascial sleeve of the body. You can experience a lot of change and glean much awareness / information about your body from these 3 sessions. Depending on the body and the patterns, this can be enough to discover and undo fascial hold-ups that are causing pain, discomfort and poor movement habits.
Once you've completed a 3 or 12 series, I work with folks independent of the series.
These are called one-off sessions.
They are thought of as a tune-up when a problem arises in your body that seems fascial in nature (posture and movement feels off, your body feels stuck in a pattern).
I need folks to complete some sort of series first to create a foundation for the one-off sessions.
SI holds the belief that most pain is symptomatic of dysfunction happening somewhere else in the body. The series helps find those source areas.
In the words of SI founder, Ida Rolf...where you think it is, it ain't.