Jason Huang
What movement trains, is actually space
Many people have had this kind of experience.
Seeing an athlete walking over, before they even speak, you can guess what sport they probably play.
Particularly broad shoulders, perhaps a swimmer; highly developed forearms, possibly a tennis or badminton player; a prominent ratio of hips to thighs, maybe a sprinter or cyclist (Figure 1).
We always think this is just "muscles getting bigger."
But if we zoom out the perspective, perhaps what truly changes is not just the muscle, but the entire soft tissue space.
Figure 1. Body types of different sports specialties.
Soft Tissue Space
The human body is not made of independent pieces of muscle, but is a three-dimensional continuous system formed jointly by skin, dermis, superficial fascia, deep fascia, fat, muscle, nerves, and blood vessels.
When a movement is repeated thousands of times a day, what gets stimulated is not just the muscle, but the soft tissue along the entire path of force.
Over time, these organizations gradually adapt to the tension, pressure, and shear forces they regularly bear, forming a physique characteristic of that sport.
Therefore, what we see is not just muscle size, but the entire body space being gradually shaped to meet the needs of that sport (Figure 2).
Figure 2. During exercise, all tissues change together, not just muscle tissue. All soft tissue spaces undergo squeezing or lengthening changes with the movement of the joints.
Looking at physical changes through a single part (muscle group)
According to the theory of soft tissue deformation, for example, after training biceps curls for a period of time, if one only trains without stretching, it will produce the overall deformation state shown in Figure 3. When bending the elbow joint, the soft tissue space of the entire arm moves in a concentric direction. However, because the hand is gripping weight, the muscle will continue to hold the surrounding fascia and soft tissue (eccentric contraction). At this point, looking from the microscopic soft tissue space, it will still maintain a slightly squeezed state until the arm is straightened. However, the training repetitions can be as many as 60-100+ times. When the training is finished, the overall space of the biceps is shortened (Figure 3, right).
Figure 3. Schematic diagram of soft tissue space deformation after biceps curl training.
Bodybuilders' Physique
So when you are in the gym, you can observe bodybuilders. Those with large but shortened biceps cannot fully straighten their elbows. This inability to straighten involves not only muscle tissue, but the shrinkage of the entire forearm and upper arm space, affecting the mechanical environment of the surrounding fascia, tendons, and the entire anterior soft tissue. When they can straighten their arms, the overall muscle space will undergo even greater changes. Therefore, bodybuilders greatly need soft tissue maintenance and relaxation to keep the space maintained, which is the key to continuous muscle growth (Figure 4).
Figure 4. Bodybuilders will limit their muscle growth space due to the compression of the biceps space.
Just imagine, if such stimulation occurs in a growing child and only in a single direction, the body might lock into a certain spatial pattern early on, losing the multi-directional development opportunities it should originally have.
