The Taoist way of doing microcosmic circulation is through mobilizing one's pelvic floor muscles, and using sublimation of sexual energy. In addition to further spiritual promises, doing the microcosmic opens one front (ren 任脉) and back (du 督脉) psychic or chi-channels, the opening of which is believed to be beneficial for one's physical health. Some martial artists of the internal styles (内家拳) also believe opening the two channels being essential to form a strong body structure.
The question is: how do the martial artists open these two chi-channels? Or: is the Taoist way the only way to open these channels?
I do believe there are other ways. I find two ways quite useful. The first way is practiced by some I-style practitioners (意拳/大成拳). Essentially it is done by micro-shaking: when a practitioner is practicing eight-direction-force-equilibrium (八面爭力) under a combat stance.
The second way is practiced by some Wu-style tai-chi practitioners, using a style under the 24 styles nei-kung. Essentially it is done by directing the force from one's soles (instead of perineum) and with using one's hands (fingers) to direct or facilitate the chi-flow along the channels. Please check this post for details: Doing microcosmic through tai chi nei-gung
Needless to say these are advanced techniques requiring a good foundation in either martial arts form for a good execution.