I was thinking of different things, according to buddhism, atleast in its tantric knowledge, there are certain states of mind that are similar: orgasm, sleep, fainting and death. In these the mind experiences what is called "energy (or prana) entering the central channel (avadhuti)", it also true of concentrated states of mind. These mental states are similar to orgasm, or orgasm is similar to them. It happens also when an artist is very concentrated in the creative process or in the performing arts in an act of intensive performance. This is well-known too, and in accordance with the tantric view and practice. This is not always the case however, must be emphasized, and there is faked "artistic intensity", etc...
It would be very odd for a person to experience sexual arousal or release from meditating or doing artwork. When they say they are similar I think what is meant is that they are similar in terms of the subtle body and concentration of energy, but not similar in terms of the gross body and mundane thoughts & feelings, like the experience of physical pleasure. Art and meditation can be reflections of sub-conscious libido, but are not the same thing as conscious sexual desire and fulfillment.
To answer your original question: What is called "abstinence," is refraining from conscious sexual desire and fulfillment. But one could also refer to refraining from subconscious sexual desire and fulfillment (if possible?) as a form of abstinence as well. Almost anything that could be said of conscious sexual desire could equally be said of subconscious libido, although it is not necessarily skillful to say so, nor is it necessarily skillful to abstain from conscious and subconscious sexual desire and fulfillment. For the average person, conscious sexual desire is enough of a burden; concerning themselves with the subconscious sexual desire would be just another burden. For the superior person, all sexual desire -- conscious, subconscious, and whatever might be beyond -- is cut off entirely. Any entertaining of that desire is only the context in which wisdom is accumulated. When there is the final accumulation of wisdom and "sattva," is removed from "bodhisattva," leaving only bodhi, in that case sex and art are no longer necessary. In the meantime, they can be necessary.