What is Normal?: Sexual Response Cycle
The sexual response cycle describes what changes the body undergoes as it becomes aroused. It is an individualized process; everyone experiences the cycle differently, although almost all people go through a similar process. It is important to note that the cycle takes place during any sexual activity where a person becomes aroused—masturbation, intercourse, manual stimulation by a partner, oral sex, fantasy, and more.
Over the years, researchers have explored the sexual response cycles of men and women. There are two popular sexual response cycles: Masters and Johnson’s Four Phase Model and Kaplan’s Three Phase Model.
The first of the phases, excitement can last anywhere from less than a minute to several hours. There is also an increase in heart rate and blood pressure. Typically, the sexual organs, including the clitoris, labia, and breasts, become engorged with blood (vasocongestion) and often become a
deeper color. Lubrication is usually produced in the vagina during the excitement phase.
The plateau phase is generally short in length (a few seconds to a few minutes) and the sexual tension that started in the excitement phase continues to grow. Extending the plateau phase sometimes can lead to more intense orgasms. Everything that occurred during the excitement
phase continues to occur, but with more intensity—breathing becomes heavier, the sexual organs become a dark color, heart rate and blood pressure continue to rise, and muscle tension increases.
The orgasm phase is the shortest phase of the sexual response cycle, generally only lasting several seconds. Women do not always enter into the orgasm phase; sometimes they stay in the plateau phase. Most women experience rhythmic muscle contractions during the orgasm phase,
which can occur in the genitals, as well as all over the body.
The resolution phase is the final stage to the sexual response cycle. During the resolution phase, all sexual organs return to their non-aroused shape, size, and color. This change begins immediately after orgasm as long as there is no additional stimulation. The amount of time it takes for a
person’s sexual organs to return to their non-aroused state varies between individuals.
Kaplan’s Three Phase Model
A unique stage to this model is the desire phase; most other sexual response cycles do not include this phase. In the desire phase, it is assumed that people want to engage in sexual activity; that they desire the activity and/or another person. Not all sexual activity is desired, though. For
example, a couple trying to conceive a child may have sex even if they do not desire the activity.
The first of the phases, excitement can last anywhere from less than a minute to several hours. Myotonia, which is categorized by increased muscle tension and flexing and contractions of the muscles, occurs during the excitement phase. There is also an increase in heart rate and blood
pressure. Typically, the sexual organs become engorged with blood (vasocongestion), including the clitoris, labia, and breasts, and often become a deeper color. Lubrication is usually produced in the vagina during the excitement phase.
The orgasm phase is the shortest phase of the sexual response cycle, generally only lasting a few seconds. Most women experience rhythmic muscle contractions during the orgasm phase. It is not unusual for people to pass back and forth between phases or for people to miss a phase.
Not everyone follows the sexual response cycle exactly as is shown here. It is also common for people to experience the cycle differently each time they engage in sexual activity. The sexual response cycle simply serves as a model to help to understand the variety of sexual responses that
people may experience.